Can we have it all? Towards a circular model for the built environment by Eliah Mallants

CAN WE HAVE IT ALL? Towards a circular model for the built environment

Submitted by: Eliah Mallants Supervisor: Prof. Pieter Pauwels Counsellor: Marc De Kooning Master's dissertation submitted in order to obtain the academic degree of Master of Science in de ingenieurswetenschappen: architectuur Department of Architecture and Urban Planning Chair: Prof. dr. ir. Arnold Janssens Faculty of Engineering and Architecture Academic year 2017-2018

Can we have it all? Towards a circular model for the built environment Eliah Mallants

Supervisor: Prof. Pieter Pauwels Counsellor: Marc De Kooning Master's dissertation submitted in order to obtain the academic degree of Master of Science in de ingenieurswetenschappen: architectuur

Department of Architecture and Urban Planning Chair: Prof. dr. ir. Arnold Janssens Faculty of Engineering and Architecture Academic year 2017-2018

PREFACE Dear reader, This disse tatio is the esult of a ea s o th of esea h, i for sustainable architecture. For this, I am grateful to

hi h I t

to o e

e thusias

My promotor, prof. Pieter Pauwels, for giving me the opportunity to pursue this topic in my own way, while guiding me every step of the way. My counsellor, Marc De Kooning, for introducing me to the subject and providing his unconventional viewpoints. My partner, AnaĂŻs, for supporting me and tirelessly listening to my ramblings on sustainability. My dear friend, Fideel, for proofreading my writings, despite my absence. Thank you

PERMISSION TO USE "De auteur geeft de toelating deze masterproef voor consultatie beschikbaar te stellen en delen van de masterproef te kopiĂŤren voor persoonlijk gebruik. Elk ander gebruik valt onder de bepalingen van het auteursrecht, in het bijzonder met betrekking tot de verplichting de bron uitdrukkelijk te vermelden bij het aanhalen van resultaten uit deze masterproef." "The author gives permission to make this master dissertation available for consultation and to copy parts of this master dissertation for personal use. In the case of any other use, the copyright terms have to be respected, in particular with regard to the obligation to state expressly the source when quoting results from this master dissertation." Eliah Mallants, 31 mei 2018

iii

OVERVIEW Title: Can we have it all? Towards a circular model for the built environment Supervisor: Prof. Pieter Pauwels Counsellor: Marc De Kooning Master's dissertation submitted in order to obtain the academic degree of Master of Science in de ingenieurswetenschappen: architectuur Department of Architecture and Urban Planning Chair: Prof. dr. ir. Arnold Janssens Faculty of Engineering and Architecture Academic year 2017-2018 Abstract The current trend towards sustainability tries to reduce the negative impact of buildings on the environment. This strategy has only shown limited success, in part because additional costs make uildi g g ee affo da le to a i o it o l . This requires a new way of building, a solution that benefits society, the environment and the economy. From the scale of building elements to that of the city, different concepts are explored to offer a holistic solution called circular building. As the subject that is covered is very broad they are clarified using examples from within and beyond Europe. The final chapter summarizes the main features of circular building. This stud s ai goal is to add ess the ole of a hite ts a d uildi gs i a ha gi g so iet . B means does it offer a final answer on the topic of sustainable building. The reader is invited to broaden his scope, yet remain critical of the presented solutions.

Keywords: circular economy, buildings as material banks, urban metabolism

NEDERLANDS EXTENDED ABSTRACT Context De actuele duurzaamheidsbeweging doet een poging om de impact van de bouwpraktijk te reduceren. In plaats van een werkelijke transitie naar een nieuw systeem, gaat het slechts om optimalisaties; minder slecht, in plaats van goed. Bovendien heeft slechts een minderheid toegang tot deze oplossingen vanwege de bijkomende kosten die met duurzaam bouwen gepaard gaan. De bouwsector staat onder druk langs verschillende fronten: •

Sociaal: er heerst een nijpend woningtekort terwijl de gebouwde omgeving grotendeels onderbenut blijft.

•

Ecologisch: gebouwen zijn verantwoordelijk voor een groot deel van onze grondstoffenconsumptie en hebben een aanzienlijke impact op onze omgeving.

•

Economisch: we kunnen de groeiende wereldbevolking en levensstandaarden niet bijhouden met onleefbare steden en een onbetaalbare infrastructuur tot gevolg.

Dit zijn symptomen van eenzelfde probleem, een onduurzaam gebouwde omgeving. Inhoud Dit probleem vraagt om een nieuwe manier van bouwen, een oplossing die zowel de maatschappij, de omgeving, als de economie ten goede komt (people, planet, profit). Circulair bouwen kan hierop een antwoord bieden. Deze thesis probeert aan de hand van concepten op verschillende schalen te achterhalen wat circulair bouwen inhoudt, gaande van het bouwelement tot het niveau van de stad. De bedoeling is om de leemte in de literatuur te duiden, een overzicht te bieden dat als aanknopingspunt voor verder onderzoek kan dienen en de rol van architecten en gebouwen in een veranderende samenleving te duiden. In het tweede hoofdstuk worden de onderliggende principes van het circulaire bouwen voorgesteld. Deze zijn gebaseerd op de circulaire economie, in tegenstelling tot het huidige take-make-dispose model. Een lineaire economie werkt grondstoffenconsumptie en kortere gebruiksduur in de hand. De circulaire economie daarentegen verschaft andere businessmodellen die verantwoordelijkheid en waardebehoud aanmoedigen. Welke businessmodellen zijn dit en wanneer worden ze best toegepast? In het derde hoofdstuk wordt gekeken naar de technologische ontwikkelingen die circulariteit van gebouwen mogelijk maakt. Een circulair gebouw is een tijdelijke samenkomst van componenten en materialen met een gedocumenteerde identiteit. Een dergelijk gebouw dat tegelijk aanpasbaar is en over een materialenpasspoort beschikt, noemen we een materialenbank. In het vierde hoofdstuk wordt besproken hoe circulaire gebouwen binnen een groter netwerk, zoals de stad, bijdragen aan de duurzaamheid van het gehele systeem. Hierbij wordt verder gekeken dan louter de bouwcomponenten, maar komt het geheel van grondstoffen aan bod die deel uitmaken van het functioneren van een gebouw zoals ook water, elektriciteit, afval en grond. Cases Tenslotte worden de belangrijkste circulaire concepten samengevat in een lijst van criteria waaraan de circulair gebouwde omgeving aan kan voldoen, zowel op gebouw als stedelijk niveau. Vervolgens worden deze gebruikt om een circulaire ontwikkeling te toetsen die, op het moment van schrijven, aan de gang is. Dit vormt de conclusie van de thesis.

v Uit de oplossingen die naar voren komen, blijkt dat de bouwsector zich zal moeten heruitvinden, wil ze kunnen beantwoorden aan een steeds dynamischere samenleving. Op technologisch vlak zal er een inhaalbeweging nodig zijn, voornamelijk qua digitalisering. Een succesvolle transitie zal echter ook een mentaliteitswijziging vereisen, waarbij zowel gebouwen als steden op een meer holistische wijze moeten benaderd worden. Het is verleidelijk de status quo als noodzakelijk kwaad te beschouwen en een nieuw model te verwerpen. De bouwsector in het bijzonder is gekend om zijn inertie. Echter, onder voldoende druk kan een transitie tot stand komen. Overheden en bedrijven doen momenteel pogingen om nieuwe strategieën te formuleren. Wie dit niet doet zal onherroepelijk achterblijven. Om de concepten die gepresenteerd worden te verduidelijken worden verschillende voorbeelden aangehaald. Aangezien het thema erg breed is, zijn deze voorbeelden afkomstig van binnen en buiten Europa. Dit laat ons een ruimer blikveld toe en voorkomt dat een enkel voorbeeld als totaaloplossing naar voren wordt geschoven. Deze voorbeelden zijn niet zonder hun tekorten, maar dragen enig bewijs naar voren dat de ideeën die ze vertegenwoordigen gegrond zijn in de realiteit van vandaag. Anderzijds moeten we sceptisch blijven tegenover ogenschijnlijk allesomvattende antwoorden. Circulair bouwen staat nog in zijn kinderschoenen en zal ongetwijfeld nog verschillende iteraties doormaken. Nieuwe problemen en technologieën zullen ontstaan die de vorige overbodig zullen maken. Daarom raad ik de lezer aan een kritische blik aan te wenden, eerder dan de voorgestelde oplossingen blindelings te aanvaarden.

ENGLISH EXTENDED ABSTRACT Context The current sustainability paradigm is focused on reducing the impact of the housing sector. Instead of a transition, all effort is directed towards optimising the current system; less bad instead of good. On top of that these solutions are only accessible for the minority that can afford the additional costs associated with sustainable building. The housing and construction sector is facing problems on multiple fronts: â&#x20AC;˘

Socially: there is an acute housing shortage, while our built environment remains largely unused.

â&#x20AC;˘

Ecologically: buildings have a major share in the global resource consumption and are detrimental to our environment

â&#x20AC;˘

Economically: construction productivity cannot cope with a rapidly growing global population and living standard, resulting in unliveable cities with lacking infrastructure

These are different symptoms of the same problem, a fundamentally unsustainable built environment. Content This problem requires a new way of building, a solution that is beneficial to people, planet and profit. Circular building could be that solution. This dissertation tries to find out what circular building is all about by exploring concepts on multiple levels, ranging from building element to the scale of the city. The goal is to address the hiatus in toda s lite atu e o e i g i ula uildi g, to p o ide a overview that can serve as a starting point for further research and to clarify the role of the housing sector in a changing society. In the second chapter the underlying principles of circular building are explored. These are based on the circular economy, in contrast to the take-make-dispose model of our current economy. Our linear economy stimulates resource consumption and shorter product lifecycles. The circular economy by contrast provides alternative business models that encourage responsibility and value retention. Which business models are these and when are they best applied? The third chapter is about the technological developments that made circular building possible. A circular building is a temporary collection of components that are identifiable. Such a building that is both adaptable and documented in a material passport is called a material bank. The fourth chapter discusses how a circular building functioning in a larger network like a city can contribute to the sustainability of the overall system. Here we look beyond building components, also addressing other resources that are parts of our built environment like water, electricity, waste and land. Cases As a conclusion to this dissertation, the important circular concepts and techniques are summarized in a list of criteria for a circular built environment, both on a building level and on an urban level, which is used to evaluate a circular development that is ongoing at the time of writing.

vii The presented solutions emphasize the necessity for the housing sector to evolve, or it will no longer be able to keep up with a changing society. This requires technological innovation, especially in the field of digitization. A successful transition however also requires a change of mentality in which buildings and cities alike are approached in a more holistic manner. It is easy to dismiss a new model in favour of the status quo. Especially the construction sector is known for its reluctance to change. Yet under enough pressure transitions do occur once in a while. At the time of writing, governments and businesses are already adopting circular models. Ultimately, those who are unable to follow will probably be replaced by those who can. To clarify some of the concepts that are discussed, several examples are presented. As the subject is very broad, these examples are diverse and originate both from within and beyond Europe. This enables us to broaden our scope and prevents one concept from being presented as the final answer, while others are disregarded. By no means are these examples flawless, but they carry some proof that that the ideas the o t i ute a e ia le a d ooted i toda s ealit . On the other hand, we should remain sceptic when presented with a silver bullet. Circular building is still in its infancy and is bound to evolve. New problems and technologies will emerge, rendering previous ones obsolete. As such, I advise the reader to remain critical about the solutions presented here, rather than accepting them dogmatically.

viii

TABLE OF CONTENTS Preface...................................................................................................................................................... i Permission to use .....................................................................................................................................ii Overview..................................................................................................................................................iii Nederlands extended abstract ................................................................................................................ iv English extended abstract ....................................................................................................................... vi Table of contents ................................................................................................................................... viii Table of figures .........................................................................................................................................x List of abbreviations ............................................................................................................................... xii 1

Sustainability ................................................................................................................................... 1 1.1

Planet....................................................................................................................................... 3

1.2

Profit ........................................................................................................................................ 3

1.3

People ...................................................................................................................................... 4

1.4

Circular building....................................................................................................................... 5

1.5

Method and acknowledgement .............................................................................................. 5

Circular economy............................................................................................................................. 7 2.1

Linear model ............................................................................................................................ 8

2.2

Green model .......................................................................................................................... 11

2.3

Circular model ....................................................................................................................... 13

2.3.1

principles ....................................................................................................................... 14

2.3.2

conditions ...................................................................................................................... 15

2.3.3

consequences ................................................................................................................ 15

2.4

Circular business models ....................................................................................................... 16

2.5

Transition............................................................................................................................... 18

2.5.1

Government .................................................................................................................. 20

2.5.2

Citizens .......................................................................................................................... 21

2.6 3

Conclusion ............................................................................................................................. 21

Buildings As Material Banks .......................................................................................................... 23 3.1

Current building practice ....................................................................................................... 24

3.2

Industrial architecture ........................................................................................................... 26

3.3

Adaptable building ................................................................................................................ 30

3.3.1

scenarios ........................................................................................................................ 30

3.3.2

compatible ..................................................................................................................... 33

ix 3.3.3 3.4

value .............................................................................................................................. 38

3.4.2

exchange........................................................................................................................ 40

3.4.3

monitoring ..................................................................................................................... 41

conclusion .............................................................................................................................. 44

Urban Metabolism......................................................................................................................... 47 4.1

urbanization .......................................................................................................................... 48

4.2

Earthships .............................................................................................................................. 50

4.3

A wealth of flows ................................................................................................................... 52

4.3.1

The circular city ............................................................................................................. 52

4.3.2

Digitalization .................................................................................................................. 53

4.4

Space ..................................................................................................................................... 54

4.4.1

adaptability .................................................................................................................... 56

4.4.2

property ......................................................................................................................... 58

4.5

Urban biocycles ..................................................................................................................... 60

4.5.1

waste ............................................................................................................................. 61

4.5.2

vegetation...................................................................................................................... 64

4.5.3

food ............................................................................................................................... 67

4.6

Energy .................................................................................................................................... 69

4.6.1

distribution .................................................................................................................... 70

4.6.2

generation - storage ...................................................................................................... 71

4.7

People .................................................................................................................................... 74

4.7.1

Housing .......................................................................................................................... 74

4.7.2

mobility .......................................................................................................................... 76

4.8 5

Material passport .................................................................................................................. 38

3.4.1

3.5 4

reversible ....................................................................................................................... 35

Conclusion ............................................................................................................................. 81

Summary........................................................................................................................................ 83 5.1

Circular criteria ...................................................................................................................... 84

5.2

Case Buiksloterham ............................................................................................................... 88

Bibliography........................................................................................................................................... 93

TABLE OF FIGURES Figure 1: the triple bottom line of sustainable development ................................................................. 2 Figure 2: consumption and production of the European construction sector........................................ 3 Figure 3: underoccupation and overcrowding in Europe7...................................................................... 4 Figure 4: a circular built environment ..................................................................................................... 5 Figure 5: chapter structure ...................................................................................................................... 6 Figure 6: principles of the linear economy .............................................................................................. 8 Figure 7: Loesje addressing consumerism............................................................................................... 8 Figure 8: two kinds of planned obsolescence ......................................................................................... 9 Figure 9: how much is left ..................................................................................................................... 10 Figure 10: value loss after first use cycle............................................................................................... 11 Figure 11: limitless growth .................................................................................................................... 12 Figure 12: sustainability is more than energy use alone ....................................................................... 13 Figure 13: three economic models ........................................................................................................ 14 Figure 14: construction and housing opportunities in Denmark .......................................................... 16 Figure 15: facade-as-service .................................................................................................................. 17 Figure 16: DBFMO process .................................................................................................................... 17 Figure 17:Harvestmap is an online second-hand material marketplace .............................................. 18 Figure 18: the law of disruption ............................................................................................................ 19 Figure 19: dougnut economics .............................................................................................................. 20 Figure 20: productivity cannot keep pace with demand....................................................................... 24 Figure 21: construction sector has lower profits than other industries ............................................... 25 Figure 22:Ikea and Skanska are mass-producing affordable housing ................................................... 25 Figure 23: benefits of an open building system .................................................................................... 26 Figure 24: an open building system can be tailored to the occupant's wishes..................................... 27 Figure 25: integrated car assembly ....................................................................................................... 27 Figure 26: Loblolly house consists of cartridges that are part of an integrated assembly ................... 28 Figure 27: traditional building process versus 'construction team' ...................................................... 28 Figure 28: Virtual Design and Construction........................................................................................... 29 Figure 29: Art & Build by Van Volxem is an example of an intelligent ruin .......................................... 30 Figure 30: the combination of structure and circulation is decisive with regards to adaptability ....... 31 Figure 31 (top): common scenario of an evolving household: children leave the house, return and leave again ............................................................................................................................................. 32 Figu e iddle : LCA o pa es a uildi g ele e t s fi a ial a d e i o e tal costs over its life cycle, depending on different scenarios ............................................................................................... 32 Figu e otto : g aphi al a al sis of a apa t e t s ge e ality and adaptability using the SAGA method .................................................................................................................................................. 32 Figure 34: the E-Cube, a kit-of-parts (left) and the Dom-Ino house, a support-infill (right) ................. 33 Figure 35: despite their unconventional shape, these buildings mostly consist of standardised elements ................................................................................................................................................ 33 Figure 36: SAR applied to student housing la Mémé ............................................................................ 34 Figure 37: reversible connections for a brick façade (left) and concrete beam (right), traditionally monolithic elements.............................................................................................................................. 35 Figure 38: building layers seperated according to their function and lifecycle .................................... 36 Figure 39: adaptable concrete floorsystem .......................................................................................... 36 Figure 40: conventional connections replaced by reversible connections ........................................... 37 Figure 41: instructions for the E-Cube assembly................................................................................... 37

xi Figure 42 summary page of a material passport ................................................................................... 39 Figure 43: progressively increasing value,, ............................................................................................ 39 Figure 44: third-party-financing facilitates product-service business models ...................................... 40 Figure 45: reverse logistics .................................................................................................................... 41 Figure 46: material passport versus building passport ......................................................................... 42 Figure 47: actual and theoretical gas consumption for different energy lables ................................... 43 Figure 48: engaging people to conserve energy by monitoring their behaviour .................................. 44 Figure 49: imagining Asterdam's circular construction industry ........................................................... 45 Figure 50: global urbanization ............................................................................................................... 48 Figure 51: a city's resource flows .......................................................................................................... 48 Figure 52: climate change affecting European cities ............................................................................ 49 Figure 53: the economic power of global cities .................................................................................... 50 Figure 54: the Bullitt center is self-sustaining water and energy wise ................................................. 51 Figure 55: types of networks ................................................................................................................. 52 Figure 56: growth and funding of the P2P economy............................................................................. 54 Figure 57: the positive urbanization feedback loop .............................................................................. 54 Figure 58: property value increases even when construction price remains similar............................ 55 Figure 59: a static built environment leads to overlapping shortage and vacancy .............................. 56 Figure 60: concentrating motorized transport increases public space ................................................. 56 Figure 61: multi-purpose space ............................................................................................................. 57 Figure 62: Static layout versus anticipatory layout ............................................................................... 57 Figure 63:New York home value to replacement cost ratio (2016) ...................................................... 58 Figure 64: transfer of development rights ............................................................................................ 59 Figure 65: degrees of property ownership ............................................................................................ 60 Figure 66: Amsterdam's potential biocycle ........................................................................................... 61 Figure 67: zero wastewater with energy and nutrients recovery ......................................................... 62 Figure 68: metabolic hub on a neighbourhood level ............................................................................ 63 Figure 69: symbiosis between urban, agricultural and natural zones create a biocycle ...................... 64 Figure 70: effects of imperviousness on runoff and infiltration ........................................................... 65 Figure 71: the Venlo city hall presents a lot of green on a small surface ............................................. 66 Figure 72: distribution of energy use in the U.S. food system (2002)................................................... 67 Figure 73:aquaponic system diagram ................................................................................................... 68 Figure 74: peak PV production versus peak load .................................................................................. 69 Figure 75: collective generation and storage in a smart micro grid...................................................... 70 Figure 76: district heating network ....................................................................................................... 71 Figure 77: seperate heat and electricity generation versus cogeneration ........................................... 72 Figure 78: the effect of thermal mass ................................................................................................... 73 Figure 79: using passive design to mitigate temperature ..................................................................... 73 Figure 80: seasonal thermal energy storage ......................................................................................... 74 Figure 81: Flanders' sprawling urban zones .......................................................................................... 75 Figure 82: city's annual cost per household in Halifax, Canada ............................................................ 75 Figure 83: density can be achieved in different ways ........................................................................... 76 Figure 84: compact development can reduce transport emissions ...................................................... 77 Figure 85:mobility on demand combines complimentary technologies............................................... 78 Figure 86: one-mile walk in a compact neighbourhood or a sprawling suburb.................................... 79 Figure 87:TOD or compact nodes linked by mass transit ...................................................................... 80 Figure 88: Copehagen's transit-oriented Finger Plan ............................................................................ 80

xii Figure 89: power, vegetation, transportation, buildings, water, space and waste are all part of the urban metabolism ................................................................................................................................. 82 Figure 90: Buiksloterham's ambitions ................................................................................................... 89 Figure 91: de Ceuvel's biocyle ............................................................................................................... 90 Figure 92: Schoonschip is a floating community ................................................................................... 91 Figure 93: City plot makes the most of its roof surfaces ....................................................................... 92

LIST OF ABBREVIATIONS 3XN AC BIM BREEAM CAD CAM CLT CNC CO2 CPC DBFMO DC DWHR EU EV FSI GDP GSHP HFC HVAC IFD LBC LCA (M-)CHP P2P PUR SAR TDR TOD TU Delft UCLA UK US VDC VMRG

3 x Nielsen (architectural practice) Alternate Current Building Information Modeling Building Research Establishment Environmental Assessment Method Computer Aided Design Computer Aided Manufacturing Community Land Trust Computer Numerical Control (computercontrolled machines) Carbon diOxide Collective Private Commissioning Design Build Finance Maintain Operate Direct Current Drain Water Heat Recovery European Union Electric Vehicle Floor Surface Index Gross Domestic Product Ground Source Heat Pump HydroFluoroCarbons Heating Ventialtion Air Conditioning Industrial Flexible Demountable Living Building Concept Life Cost Analysis (Micro-)Combined Heat and Power Peer to Peer PolyURethane Stichting Architecten Research Transfer of Development Rights Transit Oriented Development Technical University Delft University of California Los Angeles United Kingdom United States Virtual Design and Construction Vereniging Metalen Ramen en Gevels

1 Sustainability

It’s the right thi g to do, it’s the s art thi g to do, it’s the profitable thi g to do Hunter Levins

The way we construct and exploit buildings is the root cause of several pressing problems. From the scale of a building element, to that of a city, our built environment is fundamentally unsustainable. Can we find a solution to these problems by turning to a circular building model? In this first chapter we will give a short overview of the impact and urgency of the challenges we are facing. Next, we will explore the concept of circular building and the solutions it offers. I the se o d hapte e ll e plo e the ea i g of the i ula e o o a d its i po ta e fo a circular building model. The third chapter discusses how a building could become a material bank and how these are different from the way we currently construct and design buildings. The fou th hapte is a out ho i ula it a also e attai ed du i g a uildi g s e ploitatio phase and its implications on a higher urban level. Finally, a checklist for circular building is provided, summarizing the more important properties to take i to a ou t du i g a uildi g s life le. When we say the housing sector is unsustainable, what exactly do we mean by this? Up till now, our main concern has been energy consumption, but this is only one aspect of a more fundamental problem. In this dissertation, we will adhere to the definition of sustainability defined by John Elkington. Ensuring that the future needs of people, planet and profit are met, going beyond purely ecological concerns. Even though these economical, social and ecological factors influence each other, we will try to address them separately below.

Figure 1: the triple bottom line of sustainable development1

Image source: So ial Sustai a ilit Aust alia - What It Is & Wh It Matte s .

1.1 PLANET Like we discussed earlier, our environmental concerns go beyond those regarding heating and electricity consumption. The housing sector itself is directly responsible for a large part of the global consumption of materials, water and energy, but brings with it an equally concerning amount of waste and CO2 production.

Figure 2: consumption and production of the European construction sector2

That is before we even address the indirect environmental effects caused by buildings: traffic emissions caused by sprawl, disappearing greenfields to satisfy our thirst for housing or the creation of heat islands in our cities.

1.2 PROFIT The construction sector is one of the largest job sectors worldwide, larger than all the manufacturing industries combined. In the EU it contributes to 8.8% (10% worldwide) of the GDP and provides 14 million jobs.3 These figures put the tremendous economic role it plays into perspective. Compared to other sectors however, the construction industry has seen little innovation in recent decades and its productivity has stagnated, even decreasing in some parts of the world. This fact combined with an ever-increasing global population, but more importantly a growing middle class, leads to an inconvenient disparity between supply and demand. The next figures4 give a sense of the task the industry is facing in the coming years. • • • •

9 billion world population by 2050 +3 billion middleclass by 2030 +3 trillion GDP in 2015 +70% housing demand by 2030

The majority of this growth will manifest itself in cities, especially in developing countries. Between a d , Chi a s iddle lass ill ea l t iple f o illio people, to illio .

Growth Within: A Circular Economy Vision for a Competitive Europe, 82. Growth Within: A Circular Economy Vision for a Competitive Europe, 91. 4 Jensen and Sommer, Building a Circular Future, 23.

In the same period of time, China is building the equivalent of 100 New Yorks to house an additional 350 million urban population. That amounts to 221 cities with a population over 1 million and 170 mass transit systems. Ou ities i f ast u tu e ill e pe ie e tremendous pressure in order to cope with this increase in housing. The mounting costs to maintain our expanding infrastructure ultimately have to be carried by governments who are finding it harder than ever to collect the necessary funds. The result is lacking public services like water infrastructure, even in affluent countries.

1.3 PEOPLE We could also state that the current housing sector is unequitable. An ever-increasing share of our budget (30% on average) is spent on housing, our largest household expense5. Fewer people can afford to buy property and are forced to rent. This leads to building occupants being less and less involved in the construction process. Everything is decided beforehand and short-term savings for developers lead to higher costs in the long term. For example, those with access to more expensive and performant construction methods can save on heating in the long run. Over 1/5th of the Flemish populatio li es i e e g -po e t , spe di g too u h of thei udgets to pa thei e e gy bills.6 The use of space is also unequally divided. First of all, there exists a chronic housing shortage, while vacancy rates for offices are higher than ever before. The housing market itself is unbalanced as well. While 50% of Europeans report living in houses that are too big, 11 million households (5%) experience severe housing deprivation, meaning overcrowding combined with lacking sanitation, a leaking roof, or insufficient light7.

Figure 3: underoccupation and overcrowding in Europe7

Growth Within: A Circular Economy Vision for a Competitive Europe, 82. EĂŠ Gezi Op Vijf Ka Ve a i g Nau elijks Betale - De Sta daa d . 7 Housi g Statisti s - Statisti s E plai ed .

1.4 CIRCULAR BUILDING From the descriptions above, we get a feeling for the unsustainability of the current built environment. What is circular building and can it be a sustainable alternative that can respond to these diverse issues? Circular building is the application of the circular economy paradigm on the construction and housing sectors. Its core principle is to retain the value of materials and products by reusing and regenerating them, instead of consuming them like we do now. This principle can be applied on multiple levels (building element, building, city) and during multiple phases (design, construction, exploitation). In order to reach circularity, one should integrate data, technique and economy.

Figure 4: a circular built environment8

1.5 METHOD AND ACKNOWLEDGEMENT This dissertation continues with a chapter on the circular economy, since this forms the prerequisite f a e o k to u de sta d i ula uildi g. The hapte s o uildi gs as ate ial a ks a d u a eta olis a e u de stood as the o se ue es of i ula uildi g.

Image source: Growth Within: A Circular Economy Vision for a Competitive Europe, 89.

Figure 5: chapter structure

The goals of this dissertation are the following: 1. To add ess the hiatus i toda s lite atu e o e i g i ula uildi g 2. To provide an overview that can serve as a starting point for further research 3. To clarify the role and stress the importance of the housing sector in a changing society Its e t al uestio , Ca i ula uildi g eet the de a ds of ou uilt e i o ep ese ted the title. Ca e ha e it all? a e i te p eted as follo s: â&#x20AC;˘ â&#x20AC;˘ â&#x20AC;˘

e t? , is

Can we own everything individually? Can we simultaneously have a socially, ecologically and economically sustainable built environment? Can we provide these solutions for everyone?

to which circular building answers: no, yes, and hopefully. It is easy to dismiss a new model in favour of the status quo. Especially the construction sector is known for its reluctance to change. Yet under enough pressure transitions do occur once in a while. At the time of writing, governments and businesses are already adopting circular models. Ultimately, those who are unable to follow will probably be replaced by those who can. To clarify some of the concepts that are discussed, several examples are presented. As the subject is very broad, these examples are diverse and originate both from within and beyond Europe. This enables us to broaden our scope and prevents one concept from being presented as the final answer, while others are disregarded. By no means are these examples flawless, but they carry some proof that that the ideas they contribute are viable and ooted i toda s ealit . On the other hand, we should remain sceptic when presented with a silver bullet. Circular building is still in its infancy and is bound to evolve. New problems and technologies will emerge, rendering previous ones obsolete. As such, I advise the reader to remain critical about the solutions presented here, rather than accepting them dogmatically.

2 Circular economy

Circular economy is not about recycling of volume, but about recycling of value John Sommer

To facilitate and understand circular building, we should first understand the principles of the circular economy. The circular economy is an economical model with sustainability as its main goal, ecologically, economically and socially. In this chapter we will start by going over the issues with the current linear economy and what makes the circular economy different. Next, we will look at the different business models it creates for the housing sector. Finally, we discuss how governments can manage a transition towards this new model and how this effects citizens.

2.1 LINEAR MODEL Toda s o su e ist so iet lies at the hea t of the sustai a ilit isis. To la if this, e just ha e to look at a products lifecycle according to our current economic model. We take material, we make a product out of it, and we dispose of it.

Figure 6: principles of the linear economy

Toda , ost of us do t u de sta d ho this ould e p o le ati , o ho thi gs ould possi l e diffe e t. E e if ou te h olog i p o es, p odu ts do t last as lo g as the used to. Thei life le is shortened on purpose, which leads to resource shortages and a growing mountain of waste. This uote f ee spee h o ga isatio Loesje u de li es the a su dit of the situatio . Wh p odu e aste if e th o it a a ?

WAAROM AFVAL PRODUCEREN

ALS HET TOCH WORDT WEGGEGOOID

Figure 7: Loesje addressing consumerism

The explanation is very simple. Our current economic model is based on throughput: more stuff equals more money. This means manufacturers benefit when their products lose their value once bought (because they break or become obsolete), so they can be replaced with new products. We call this principle planned obsolescence. Fundamentally, the linear economy is not based on the increase of value, but on devaluation.

Figure 8: two kinds of planned obsolescence9

Here we start to see the limits of sustainability. Our planet is a closed system, which means nothing leaves or enters, except for sunlight and the occasional asteroid. In other words, we only have a limited amount of resources to our disposal. The goal of the linear economy is to stimulate the consumption of resources and energy, which inherently leads to the depletion of our natural assets. The graph on the following page shows how fast we are running out of resources. This scarcity is already having detrimental effects on the economy. It leads to higher and more volatile commodity prices, which is especially worrying for regions that depend on import, like Europe. In Flanders for example, where an average business spends 53% of its expenses on resources10, these are uncertain prospects. Simultaneously, all this consumption generates a lot of waste. Not only giant landfills and plastic island, but also greenhouse gasses count as waste. While our awareness concerning emissions revolves largely around domestic energy consumption and passenger transport, the majority of all emissions (55-65%) is material-related11. To satisfy our demand for resources, we start extracting low-quality resources, which takes more energy, leading to even higher CO2 emissions.

Image source: Rau and Oberhuber, Material matters, 31. Image source: I fog afieke - Vlaa de e Ci ulai . 11 Image source: I fog afieke - Vlaa de e Ci ulai . 10

Born in 2010: How much is left for me? 2010 Energy

2020

2030

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2060

2050

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Oil

2100

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Coal Gas Uranium Metals used in Antimony renewable energy solutions Lead Indium

2856

Rare earths cerium, dysprosium, erbium, europium, gadolinium, holmium, lanthanum, lutetium, neodymium, praseodymium, samarium, terbium, thulium, ytterbium, yttrium, ferrocerium, monazite, bastnasite, mischmetal

Zinc Silver Gold

Gold production is declining

Copper

Calculations based on known reserves: Reserves

Years remaining if production continues to grow at current rates

Resources (undiscovered)

Years remaining if production remains static

Resource base (to energy intensive to extract)

Sources: US Geological Survey, Adroit Resources, World Bureau of Metal Statistics, International Copper Study Group, World Gold Council, Minormetals.com, Roskill Nickel Report, Cordell et al (2009), Smil (2000), Silver Institute, World Nuclear Association, International Lead and Zinc Study Group, Wikipedia. Source (fossil fuels): BP Statistical Review of World Energy 2010.

Where to find the leftovers?

Russia & former soviet republics Europe North America Middle-East

South-East Asia

Africa South & Central America Oceania

100% 90% 80% 70% 60% 50% 40% 30% 20% 10%

Share of total world reserves expressed as a percentage. Sources: US Geological Survey, World Nuclear Association, BP Statistical Review of World Energy 2010.

Oil Coal Gas Uranium

Antimony Lead Indium Rare earths

Zinc Silver Gold Copper

Peter Stouthuysen

Other industrial metals

2.2 GREEN MODEL How do we respond to these problems? Our current solution to the sustainability crisis is the green economy or the recycling economy. The idea is to minimise the impact of the linear economy. I stead of t a sitio i g to a e odel, it s a out opti isi g the old o e. This optimisation usually comes at a cost not everyone can afford. This means sustainability remains something only wealthy countries, companies and people can pay for, out of reach of those who cannot afford a green image. The g ee e o o uses guilt t ippi g as a st ateg to sell its p odu ts. Those ho do t pa ti ipate should feel bad about themselves, but the result is usually indifference and passive behaviour. Coupled with the notion that the effects of unsustainability are only felt far away, we are not convinced to change our ways. After all, we care more about our wallets than about polar bears. Even when we are willing to contribute to a sustai a le ause, it usuall ea s doi g less ad i stead of good . Sol i g o e p o le usuall leads to a igge o e. B the , e ha e e o e too reluctant to go back on our bad decisions. A waste incinerator for example, recovers energy from waste that otherwise would have been landfilled. This is considered to be an alternative to energy derived from fossil fuels. However, resources are irreversibly being destroyed and the emissions that are produced in the process are more polluting than those coming from coal power plants1314. Now that the energy grid is dependent o this e e a le sou e, it is too late to tu a k. I stead, this e e g is la elled as ei g g ee . This story reveals two symptoms of the green economy. The first is downcycling, meaning recycled material is of lower quality and functionality than the original material. Recycled construction steel for example, is too low-grade to be reused in new beams. Most recycled materials are not used for their original application but end up in products of inferior quality. This cycle is repeated until the ate ial s ualit has dete io ated to su h a e te t it a o lo ge e used. In the case of the waste incinerator, the energy derived from the waste is less valuable than its raw materials.

Figure 10: value loss after first use cycle15

Sea hi ge et al., Fi i g a C iti al Cli ate A ou ti g E o . EPA EGRID CO , SO a d NO E issio s Data fo U.S. Ele t i Po e Pla ts | E e g Justi e Net o k . 15 Image source: Growth Within: A Circular Economy Vision for a Competitive Europe, 18.

The second symptom, called greenwashing, occurs when green marketing is deceptively used to promote the perception that a product is environmentally friendly. Labelling waste-to-energy plants as g ee e ause aste is a e e a le esou e, de ies thei e i o e tal i pa t. As a esult, a ou t ies el o these pla ts to ea h thei sustai a ilit goals. That s like t i g to lose weight by eating sugar instead of fat. Even if a green model would reduce the environmental impact per person, it would not be enough. We are living in exponential times, which means the rapid growth of our combined impact remains inevitable. By 2030, our demand for basic commodities will increase, especially for food (+50%), energy (+50%) and water (+30%)16.

Figure 11: limitless growth17

The construction sector suffers from the same misconceptions. Currently, a sustainable building is synonymous with an energy-efficient building, which is synonymous with a well-insulated building. Because of a one-sided view on the matter, other factors such as location, occupancy rate and material use are disregarded.

16 17

Jensen and Sommer, Building a Circular Future, 23. Image source: Wh Ou E o o Is Killi g the Pla et a d What We Ca Do a out It .

Figure 12: sustainability is more than energy use alone18

The ongoing decrease in building-related energy consumption has even led to counterproductive practices. One example is the use of spray-foam insulation. In order to comply with regulations, contractors are encouraged to use PUR-foam, since it is cheap and easy to apply. This has become the default floor insulation in passive houses. As a consequence, different materials are irreversibly joined, which have to be incinerated after demolishment. The diffusion of blowing agents over time also has severe health implication, increases thermal conductivity and most shocking of all, it is a greenhouse gas 800 to 1300 times more potent than CO2. The environmental payback period takes multiple decennia (9 to 100 years depending on layer thickness), compared to only 2 years for most insulating materials. By now HFC spray-foams have been banned in several EU countries19.

2.3 CIRCULAR MODEL Is there a way to reconcile economy and sustainability? The circular economy is one alternative that can be regarded as the culmination of multiple sustainability models: service economy, cradle to cradle, biomimicry, industrial ecology, blue economy, ... Looking beyond the current take-make-dispose model, the circular economy is restorative and regenerative by design. In an ideal circular model, all impact of a human activity is considered and all activities must either produce no negative impact or be turned into a positive input in other activities, a p o ess k o as closing the loop . Rel i g o s ste -wide innovation, its approach to products and services is to design out waste, thus minimising negative impacts. Supported by a digital transition, the circular model builds economic, natural and social capital.

Image source: Va B oe k a d Bogda , De Vlaa se kli aattop op ap il . Bo e la de , Maats happelijke O e egi ge Bij Het Aa e ge a PUR-Isolatie Aan de Bovenzijde van Ru e Vloe e .

18 19

Figure 13: three economic models20

2.3.1 PRINCIPLES How does the circular economy work? As opposed to the linear take-make-dispose odel, the e s the circular regenerate-reuse-reduce model. First of all, we need to distinguish two cycles: that of the biological nutrients and that of the technical nutrients. Biological nutrients belong to the biosphere and are renewable. They are regenerated under the influence of sunlight, after which they are consumed. Finally, their residual nutrients are used as feedstock for other biological products. Example: sunlight grows cotton that is used to make a reusable bag. Once it has been worn out, it can be anaerobically digested into biofuel. Technical nutrients belong to the technosphere and are finite. Their cycle is a bit more unusual. A producer processes raw material into a product. Rather than selling the product, he provides it as a service. After a user no longer requires the service, the product returns to the producer or provider, who can use it again. When the product is worn out or no longer required, its parts can be reused in other products. Making technical nutrients available over and over is only possible thanks to data and digitalization. Example: a car is leased using a digital contract. Once the contract expires, the car is returned to the manufacturer, who can make the necessary upgrades and lease it again.

Image source: I fog afieke - Vlaa de e Ci ulai .

2.3.2 CONDITIONS What does a circular economy need? First and foremost, a transition towards a service economy and as a o se ue e, te h ologi al de elop e t that fo uses o a p odu t s e ti e life le. Today, these might seem like unattainable goals for the housing sector. Still, more and more applications of the service model are finding their way onto the market and into our buildings: separation walls as a service, office furniture as a service, carpet, elevators, ventilation, even facades as a service, the list goes on and on. These have already been tested commercially. To develop a service model, we first need to answer the uestio hat do I a tuall eed? . Architect Thomas Rau asked the same question and lau hed the p oje t Pa Pe Lu i pa t e ship ith Philips. The sta ti g poi t fo Rau s o ept is that consumers are not interested in lamps, but in the light they produce. Consequently, Pay Per Lux is not a product, but a service: the customer buys a subscription from Philips for a certain amount of light per year. Philips then supplies the lamps, ensures that the energy bill is paid and takes responsibility for replacing lamps when needed. Philips remains accountable for its own products and the e e g ill that o es ith it, so it is i the o pa s i te est to p odu e lo g-lasting, energyefficient lamps. When the lamps need replacing, the raw materials can be re-used, thus lowering the production costs of new lamps. The design of the lamps ensures they can be easily disassembled for recycling purposes. The transition from a linear to a circular model also shifts the relationship between producer and consumer. Linear consumer producer product ownership throughput conflicting interests planned obsolescence

Circular user provider service stewardship performance overlapping interests sustainable design

A major argument in favour of the circular model, as opposed to the green economy, is that achieving a sustainable world does not require changes in the quality of life for consumers, nor does it require loss of revenues or extra costs for manufacturers and other economic agents. The argument is that circular business models can be as profitable as linear models and allow consumers to keep enjoying similar products and services. 2.3.3 CONSEQUENCES What are the effects of a circular model? â&#x20AC;˘

Planet: Possibly the primary concern of the circular economy. The wellbeing of the environment is integral to the functioning of the economy. It is beneficial to both user and provider to use and regenerate resources in the most efficient way possible. As we will see in later chapters, this is not just the case for construction materials, but also water, energy or land.

•

Profit: Markets acquire economic self-sufficiency and stability. Win-win for governments, businesses and citize s. € illio esou e ost edu tio fo the o st u tio se to i the EU , o pa ed to the u e t s e a io, o € t illio e sus toda 21. People: Responsibility and control over own resources lead to more territorial cohesion on a global scale. Specifically for the construction sector, a more accessible and qualitative housing supply with more involvement of the end user.

Figure 14: construction and housing opportunities in Denmark22

2.4 CIRCULAR BUSINESS MODELS How can the construction and housing sectors put these circular principles into practice? 1. Material driven, focusing on providing the product or material with additional take-back/reuse services. Example: PROgroup has office buildings in Luxembourg featuring a wide range of sustainability concepts. For their new steel-structure parking lot, PROgroup has reached an agreement with the supplier on a buy-back option of their steel beams at deconstruction. The supplier has agreed to a price point higher than the second-hand market average, since buying back their own products significantly lowers the risks compared to acquiring used beams from other manufacturers. Deconstruction will be carried out by the supplier to ensure proper dismantling. Such buy-back schemes further incentivize suppliers to design for simple (de)construction and standardization. 2. Product performance driven, focusing on providing access to a complete performance package instead of ownership of a product. Example: It is more difficult to implement leasing systems when the product is fixed or connected to the building (like a façade), mainly due to legislation. However, in the Netherlands take-back or leasing models for façade systems are starting to be applied in a 21 22

Growth Within: A Circular Economy Vision for a Competitive Europe, 91. Delivering the Circular Economy.

joint project between VMRG and TU Delft. The idea is that the faรงade remains property of the provider. The user leases it and gets an upgrade when the contract expires. The faรงade systems comes with maintenance, operation and return services. If a part no longer works, it gets replaced the p o ide . Si e it s i thei o est i te est, the faรงade s desig is demountable and modular, which makes it easier to recuperate.

Figure 15: facade-as-service23

3. Building performance driven, focusing on providing a complete performance package on building level, basically being the main partner for building owners. Example: DBFMO (Design Build Finance Maintain Operate) is a contract in which all aspects of a project are outsourced to a consortium. Usually, a DBFMO is used for long term collaborations, since the service package covers the entire lifecycle of a building. The client e p esses spe ifi ishes ased o e ifia le esults. It s up to the o so tiu to desig a d execute an answer. This way, the consortium can employ their expertise to provide innovative and efficient solutions. The client pays for the performance but does not finance the construction. This stimulates the consortium to finish and exploit the building according to contract agreements.

FINANCE OPERATE DESIGN

BUILD

MAINTAIN

Figure 16: DBFMO process

Faรงade Leasi g pilot p oje t at TU Delft .

4. Network driven, focusing on connecting people with services in- or outside the construction industry. This is where digitalization becomes important. There exist a wide variety of digital platforms that provide services related to the construction and exploitation of buildings. These include but are not limited to: management of material passports, workplace sharing, performance monitoring and (re)distribution of products.

Figure 17:Harvestmap is an online second-hand material marketplace

All of these business models reduce raw material usage, either by reusing, repairing or as a last resort, recycling. These principles are as old as time, originally to deal with scarcity, resulting in inferior product quality. Nowadays, with the help of modern technology, these strategies can lead to more efficient and durable products. Not every business model is applicable to any part of the building process. Deciding which of the previous business models should be considered depends on several factors, such as: • • • •

Life cycle (beam/separating wall) supply risk (steel/concrete) value retention (cable tray/carpet) ownership (public/private)

2.5 TRANSITION How can we transition towards a circular economy? One thi g is e tai : it o t happe o e ight. We cannot expect producers everywhere to start implementing circular practices on their own accord. Individually, no one can change the status quo which locks everyone in perpetual business as usual. Consumers buy what is cheapest, politicians legislate whatever gains votes and businesses are motivated by profit. Despite all this, there is a disruption that is ongoing with technological innovation taking the lead. Digitalization has triggered a wave of new technologies complementary to the circular economy. This allowed the circular economy to gain exposure and the expectations surrounding it are starting to rise.

Figure 18: the law of disruption

If these e pe tatio s a e t a aged, the ircular transition will go through the typical hype cycle as e e othe eakth ough idea. The isi ilit of a i ula e o o as t igge ed te h ologi al innovation around 2010. Now, nearly ten years later, the expectations surrounding it are reaching their peak inflation. As everyone starts to jump on the bandwagon, the circular economy might not be able to live up to the hype. If this happens, the hype cycle crashes and it will take years before the circular model recovers its productivity. To prevent the abandonment of the circular economy before its potential is realized, transition management needs to slowly build a new system over the old one. There are other hurdles to take. The transition to a new system always comes at a loss. Businesses that cannot adapt will disappear, overtaken by those who can. This is inevitable, we can only decide who is going to take their place. Are these going to be P2P (peer-to-peer) platforms dominated by tech giants or are we creating a future where an entire city is owned by a single building consortium? If e a t this e e o o to e o e i lusi e, it has to o k to e e o e s e efit, athe tha consolidating the monopoly of a few multinationals24. Finally, the circular economy has to deliver on its promise to sa e the e i o e t . The ait to a circular model is its ability to couple economic growth with sustainable behaviour. In reality it s this growth can still have negative consequences. The housing market is nearly perfectly elastic, which means that for a 10% decrease in costs, demand will increase 9%. This is known as the rebound effect25. If the circular economy makes products more affordable, overall consumption will increase, offsetting any progress towards sustainability. There is no magical fix. Maybe we cannot reconcile economic growth with environmental sustainability. Does a growing economy, an increase in GDP, also mean more prosperity? Does it really improve our lives? Some say not. Alternative economic models like the donut economy for example, suggest we should only fulfil our needs in order to create a social foundation. Limiting g o th so e do t o e shoot ou e ologi al eili g eates the ight ala e et ee hu a ki d and nature.

24 25

Narberhaus and Mitschke-Colla de, Ci ula E o o Is t a Magi al Fi fo Ou E i o Growth Within: A Circular Economy Vision for a Competitive Europe, 87.

e tal Woes .

Figure 19: dougnut economics26

2.5.1 GOVERNMENT Governments around the globe play an important role in a successful transition towards a circular economy. They can regulate and incentivize the market in order to steer it towards the desired goals. Today, sustainable products are usually more expensive than their unsustainable counterparts. This is e ause of the hidde osts that a e pa ed fo so iet . A fa to ight pollute the i e , ut it s the ta pa e that pa s fo the ate t eat e t pla ts, effe ti el su sidizi g the pollute . Internalization of external environmental and social costs in prices of products is an instrument governments can use to sensitize businesses and consumers of the (long-term) impacts of a product, such as climate change, resource depletion, or health effects. Internalization of external costs, or true cost, will only work if it is applied over country borders. Another way to facilitate transition is by setting up pilot projects, subsidizing or enforcing policy by including it in mandatory assessment. Labels like BREEAM could be normalised, much like energy labels today. In Belgium, government purchases make up 17% of the total GDP27. This public procurement can be a powerful driver and can play a significant role in mainstreaming circularity practices. For example, healthy building materials remained expensive in Sweden, until municipalities started including them as requirements in their tenders. Being one of the largest client groups, demand from the Swedish public sector optimised the entire supply chain and lowered cost over time. 26

Image source: Raworth, Doughnut Economics, 38.

Public building projects are well positioned to further raising awareness and sharing experience. Karlstad is a public hospital in Sweden that used healthy building materials in a renovation. It was recognized that the additional upfront cost is insignificant compared to long-term costs. Even city politics can have a significant impact on sustainability, especially as cities are gaining influence in their national political landscapes. Mayors usually face less opposition and are often better positioned to facilitate transition. Freiburg in Germany is living proof that it is political will, vision and policy, not some mysterious green sensibility, that enables sustainable living. F ei u g s mayor and city council defined policy in the areas of transportation, energy, waste management, and land use. Direct citizen participation is also important and consolidates long term community solidarity. 2.5.2 CITIZENS As we will see, sustainability is as much a matter of individual choice as of design. As such, citizen acceptance and participation are important conditions for the circular economy to succeed. Compared to a linear model, consumers can enjoy similar services, but there are some crucial differences as well. Today, people tend to enjoy a sense of property or ownership in general, though this is changing. Instead of having your own car, the pinnacle of freedom, people drive company vehicles. Still, especially in Belgium, owning a house is perceived to be a necessity in order to enjoy comfort and self-agency. Consumerist society measures our worth by our possessions and has transformed us from citizens into consumers. The only responsibility we have left, is to vote with our wallets. Yet this individualist attitude might be the secret ingredient to integrate sustainability into our society. Not by reinvigorating the norms and values of the good old days, because that implies regression. Rather a new ethos, that leverages our competitive nature and personal freedom to take care of ourselves. Do t ode ate ou eat o su ptio e ause ou feel guilt fo eati g a i als ut do it so ou sta health . Bei g sustai a le fo o e s o sake, sustainable individualism28.

2.6 CONCLUSION Understanding of the circular economy is a requirement for circular building to work. The circular economy is an economical model which revolves around social, environmental and economic sustainability as an alternative to the linear economy. First, we discussed the problems of the current take-make-dispose model. It purposely stimulates resource consumption through devaluation in an attempt to increase throughput. As a result, we generate more waste and our natural reserves are becoming scarce. The current solution aims to optimise this system but is conflicting with our growing needs and destined to fail. Then we learned the main principles that drive the circular economy. By shifting towards a regenerate-reuse-reduce model, we can close the technical and biological material loops. This creates value as opposed to the linear model, by using performance to link economy with sustainability.

Re so , We ge iete o s te plette . Maa

ie a d is te ede .

We applied these principles on multiple business models that are suited for the housing and construction sector. Depending on several factors, these models are either material driven, performance driven, or network driven, but all incentivize service providers to take responsibility for their products. Finally, we discussed how a transition to this new economy has already started. Governments need to find a way to manage these disruptions caused by technological innovation. Tools like true cost pricing, public procurement and city politics are ways to steer the economy in such a way that it remains beneficial to businesses and citizens alike. Citizens themselves will also play a significant role i this t a sitio . Ou i di idualist so iet ould tu out to e the ke to ha ge people s eha iou towards sustainability. If the status quo remains, sustainability is just a pipedream. But betting everything on a magical fix is risky as well. We have to remain critical towards change and keep referring to our original intentions or we might end up worse than before.

3 Buildings As Material Banks

A uildi g is ot so ethi g you fi ish, itâ&#x20AC;&#x2122;s so ethi g you start Stuart Brand

In this hapte e ll go o e ho i ula uildi gs a e diffe e t f o the way they are designed and constructed.

t aditio al uildi gs, ega di g

First, we will discuss the construction process and the benefits of an industrialised architecture. Then we will examine how our decisions during the design phase determines the adaptability of a building. Finally, the concept of ate ial passpo t is e plo ed as well as the effect it has on the exploitation phase a d the e d of a uildi g s life le.

3.1 CURRENT BUILDING PRACTICE What problems do we face in our current construction model? The construction sector should be able to keep up with the growing demand for real estate, but it struggles to do so because of the low, even declining, productivity that is the result of several factors: • • •

Low profits High risks Fragmented market

This means there is not enough cash-flow to warrant investment in development, causing it to be the least innovative and digitized industrial sector29. If the construction sector were to experience half the productivity increase other manufacturing sectors benefit from, costs would decrease by 50%30.

Figure 20: productivity cannot keep pace with demand31

The current construction process is almost archaic paradigm that has t e ol ed i a sig ifi a t way in over a century. Buildings are complex puzzles made up of several thousand parts assembled manually, often piece by piece, on site. This leads to a costly and wasteful building process, resulting in 15% of the used materials being lost. On average, projects costs turn out 80% higher than anticipated and take about 20 % longer to finish32. Yet, the initial cost of a building says little about the costs through its entire lifetime, which usually amounts to a staggering 3 to 5 times the original building cost33.

Ma ika et al., Digital A e i a . Growth Within: A Circular Economy Vision for a Competitive Europe, 83. 31 Image source: Attia, Haiti s Re uildi g -- The La ge Pi tu e . 32 Bla o, Ja auskas, a d Ri ei i ho, Beati g the Lo -P odu ti it T ap . 33 Padua t, Ci ulai ou e . Ee le e s lus isie op ge ou e als ate iaalbanken als samenspel tussen e s hille de a to e .

Figure 21: construction sector has lower profits than other industries34

We construct buildings as if they were everlasting, increasing their technical lifespan, while new technologies and an increase in user mobility means they become obsolete at a rate faster than ever before. Disruptive technologies are already here, but the construction sector needs to adopt them or it will be overrun by new players and multinationals. IKEA already completed several real estate projects in Sweden and even in the UK, providing ready to move in housing, complete with furnishing. Even tech giants are looking to claim a piece of the real estate pie. Sidewalks Lab, a subsidiary of Google, is going to develop the Toronto Quayside. Their goal is to provide living and working space for 80.000 people, integrating the latest in digital technology to monitor (and sell) enormous amounts of data. This effectively turns the city into a giant piece of hardware which will be indispensable to architects, developers and inhabitants alike, offering cheaper housing, more efficient energy use, better connectivity, etc.

Figure 22:Ikea and Skanska are mass-producing affordable housing35

34 35

Image source: Ad ia S ith, Agile a d Lea fo Co st u tio . Image source: Rose, Ste e Rose T a els to S ede to Sa ple Life i Ikea s Read

ade Ho es .

3.2 INDUSTRIAL ARCHITECTURE Which technologies are disrupting the market and how are they steering it towards circular design and construction? If the sector wants to become more productive, it should integrate technologies and trends that are based on other industries. We can think of product development, but especially manufacturing industries such as the car industry. It can be hard to imagine the impact this could have, but it is easier to imagine the opposite case. This narrative36 sheds some light on how dated our way of building is, and the reverse, what an industrialised building practice could offer. If cars were built like houses: • • • • • •

each one would be built outdoors, exposed, in the middle of a muddy field. each car would be slightly different than all others, and would be built under different laws, depending on where the muddy field was located. Each part of the car would be put together and installed by a different company, with different workers guided by different supervisors, on different schedules Sometimes in the rush to finish the car, the battery or steering wheel wouldn't arrive in time car shoppers would never drive the car before they bought it, and no one would ask about the mileage per gallon, since no manufacturer ever bothered to test it these cars would cost hundreds of thousands of dollars

IFD (Industrial Flexible Demountable). When we think of industrial architecture, the first thing that comes to mind is serial prefabrication, a relic from the modernist past. This is still the case for most building elements today, since this is the only way to keep costs from spiralling out of control. Assembly however, still takes places on the building site. This kind of prefabrication is the result of a closed building system, that is tailored to a single design, never to be used again afterward.

Figure 23: benefits of an open building system37

36 37

Home Performance, If Cars Were Built like Houses... Image source: De T o e , A hite tuu k aliteit E Maato de i g De Belgis he Situatie .

In an open industrialisation, the system comes before the design. At first, this system-before-design approach might seem to limit the freedom the architect or client has. Yet the opposite might be true. Instead of similar designs, made of unique elements, we would get unique designs made of similar elements, quite in the same way LEGO (an open building system) allows for endless creativity and variation. New CAD/CAM techniques could further facilitate mass customization, tailoring a design to the individual user, without an increase in cost.

Figure 24: an open building system can be tailored to the occupant's wishes38

This s ste s app oa h ould t just help the desig p o ess, ut also ould also st ea li e the construction process. Instead of having all parts arrive on site to be assembled, we can gradually build clusters of parts into modules. In the car industry this process is alled integrated assembly , and it improves the quality while reducing the cost of the product.

Figure 25: integrated car assembly39

Because the modules are organised in tiers, they can contain as many parts as they need, without e o i g too o pli ated to ha dle. A odule, so eti es alled a hu k , a e a thi g a gi g from a bathroom, to a floor, to an exterior wall. Instead of multiple independent contractors working on a single element, all parts of a module are asse led i o e o kshop. Whe the e fi ished, they are delivered on site and quickly installed. These buildings are not the concrete monstrosities e thi k of he e hea the o ds i dust ial a hite tu e , uite the opposite.

38 39

Tila Housi g Talli A hite tu e a d Desig | Apa t e t Blo ks . Kieran and Timberlake, Refabricating ARCHITECTURE.

Figure 26: Loblolly house consists of cartridges that are part of an integrated assembly40

LBC (Living Building Concept). Not just the building process needs to be addressed, problems arise long before the first wall has been drawn on paper. Currently the development of a building is a linear process, organised between three parties in an antagonistic relationship: the client, the architect and the contractor. Neither the final occupant, nor the supplier are involved in this process, yet these parties ultimately use and produce the building. Disregarding the innovation brought by the supplier and the changing lifestyle of the occupant means a building is usually outdated before it s fi ished. Fo the lie t, this ill p o a l e the fi st a d also the last time he is involved in a risky building process. Yet without any prior experience, he has to specify what he will need. LBC proposes instead that the client no longer expresses himself in terms of exact specifications, but rather in terms of certain needs and ambitions. Contractors and architects combine their expertise to p opose a solutio . This is alled the apid p o u e e t phase . The lie t the sele ts the ost suita le solutio a d togethe ith the a hite t a d o t a to fo s a construction team (nl: bouwteam , hi h is the sta t of the o kout pe iod . Fi all , tou h do happe s he all performance specifications have been defined. When we include the occupants, suppliers and building managers in a construction team, designing a building for its entire lifecycle becomes possible, hence the name Living Building Design.

Figure 27: traditional building process versus 'construction team'41

40 41

Image source: Lo loll House | P efa i ated A hite tu e I teg ated ith Natu e . Image source: Het Vlaa s I o atie et e k .

BIM / VDC (Building Information Modelling / Virtual Design & Construction) Sometimes BIM is confused with 3D CAD. The important difference is the added information that is embedded within a Building Information Model. Going beyond the 3 spatial dimensions, time and cost are taken into account, sometimes referred to as the 4th and 5th dimension of a building. Beyond the ability to visualise in detail what a building will look like, structural and technical characteristics are part of the same model. Instead of different plans going back and forth between the different building partners, a single model is shared between architects, engineers, and other stakeholders. In a way, BIM is a tool used to communicate and collaborate, rather than a design tool. Instead of having raw geometry, a BIM is made of self-contained elements (e.g. a single column), called instances. An instance can contain information about its geometry, price, weight, conductivity, etc. These instances are hierarchically organised in types (all columns with the exact same properties), which belong to a family (all round columns), which belong to a category (all columns). VDC in its turn is often confused with BIM, because of its shared and virtual character. But rather than being a tool meant for designing, Virtual Design and Construction is a process used to optimise the construction phase of a building. Schedules can be made, simulating how long a certain building phase takes, what equipment is needed, what the cash flow is, when parts should be ordered, etc. These methods of planning, organising and collaborating greatly increase the efficiency with which design and construction are executed.

Figure 28: Virtual Design and Construction42

How does this all tie in with circular building? As we have seen in the previous chapter, for a building to be circular, it has to be a temporary collection of materials, a material depot of sorts. For someone to recuperate these materials, the building needs to be adaptable, and its parts identifiable. These disruptive technologies are crucial if we want to achieve this. The ultimate goal is to create a building that not only keeps its original value, but increases it. A building as material bank.

Image source: Vico software, 4D BIM Scheduling for Dummies.

3.3 ADAPTABLE BUILDING What is timeless? Monuments maybe, but there are very few buildings that have this quality. Especially when our demands and ambitions are changing faster than ever before. But how do we design buildings in such a way that they stay useful, even when times change? Adaptability is the degree to which a building can support change. There are many forms of adaptability depending on which timeframe we are looking at (days, months, years), yet we can categorise them either as generality, movability or transformability. •

•

Generality: A building or space is general or multi-pu pose he it s desig ed i such a way that it can support changing needs and requirements without having to make physical changes to the building or spatial layout. Movability: Integrating moveable components, such as sliding, pivoting or foldable walls in building elements or fit-out, makes it possible to adapt a room or building into a number of predetermined configurations. Transformability: Buildings that can be adapted in many different ways because some or all of their components can be disassembled, and then reconfigured to support changes in needs and requirements.

3.3.1 SCENARIOS One way to make a building last is by organising its spaces in such a way that in the long run they can be used in different ways, without the need for radical alterations. There are three important factors to consider if we want a design that is suitable for different functions. 1. St u tu e, e ause it s ha d to ha ge afte a d 2. Circulation, because it allows us to access and divide space 3. Technical distribution, because it determines where functions can occur The office building below (left) is an example of adaptable design through clever organisation of the factors mentioned above. When in the future its office function becomes obsolete, it can become an apartment building (middle) simply by installing a few separation walls. If we were to strip the building of everything but its structure, circulation and techniques, we get what is called an intelligent ruin ight .

Figure 29: Art & Build by Van Volxem is an example of an intelligent ruin43

Padua t, Ci ulai ou e . Ee le e s e s hille de a to e , .

lus isie op ge ou e als

ate iaal a ke als sa e spel tusse

Different combinations of structure, circulation and techniques result in different kinds of ruins, some more intelligent than others, but there is no single most flexible layout. A load bearing faรงade for example, allows for the most internal flexibility, but is unfit for external expansion. Trying take every possibility into account leads to generic and costly design, usually more detrimental to the environment than a conventional design would be.

Figure 30: the combination of structure and circulation is decisive with regards to adaptability44

In the absence of an infinitely adaptable layout, which one should we pick? This choice can be informed by developing scenarios. Scenarios are stories, exploring imaginable but divergent futures. They express how a building might change and take into account the owner s knowledge about future requirements and the designer s i sight i the uildi g s adapta ilit . Once probable scenarios have been determined, we can compare different designs using an LCA or Life Cycle Analysis. This is a set of techniques used to assess environmental impacts, and financial costs asso iated ith all the stages of a uildi g s life f o a ate ial e t a tio th ough manufacture, maintenance, and end of life, commonly known as cradle to grave.

Padua t, Re-Design for Change. A 4 Dimensional Renovation Approach towards a Dynamic and Sustainable Buildi g Sto k .

Figure 31 (top): common scenario of an evolving household: children leave the house, return and leave again45 Figure 32 (middle): LCA compares a building ele e tâ&#x20AC;&#x2122;s fi a ial a d e viro different scenarios46 Figure 33

otto

e tal osts over its life y le, depe di g o

: graphi al a alysis of a apart e tâ&#x20AC;&#x2122;s ge erality a d adapta ility usi g the SAGA

ethod 47

Friedman, The Adaptable House. Galle, Va de ou ke, a d De Te e a , Life C le Costi g as a Ea l Stage Feasi ilit A al sis . 47 He thogs et al., E aluati g the Ge e alit a d Adapta ilit of Floo Pla s Usi g the SAGA Method .

Depending on the freque a d e te t of t a sfo atio , o e ight o lude that the uildi g s ui ill e sho t li ed, i hi h ase a kit of parts a o pletel de ou ta le st u tu e ight e more appropriate. If on the other hand the building is well located and satisfies future demands, a support-infill pe a e t st u tu e is o e suited fo lo ge it .

Figure 34: the E-Cube, a kit-of-parts (left)48 and the Dom-Ino house, a support-infill (right)49

3.3.2 COMPATIBLE As we discussed above, an open building system not only allows for a faster construction phase, but also makes the parts interchangeable between different buildings. We could say one building system is compatible with another. This allows for easier building adaptability while also extending the lifetime of materials and products. Since buildings are often made out of repetitive components (one type of roof, floor, faรงade,), using modular and standardised building elements makes sense.

Figure 35: despite their unconventional shape, these buildings mostly consist of standardised elements50

Instead of having to tailor each individual element to the next, a modular building system means e e ele e t has its pla e, ot o l ithi the uildi g it s a pa t of, ut in any building made according to the same modular system. Rottie s, E-Cu e . E e ge t H id P efa St u tu es i D elli gs . 50 Jensen and Sommer, Building a Circular Future, 114.

To some this might sound like an unattainable and undesirable goal, yet modularity is as old as building itself. Most countries have standardised brick sizes such as 190mm x 90mm x 50 mm, meaning a brick from a facade can be recuperated and used in another facade. If we were to transform the same materials into different buildings over and over, without destroying materials, we would never need to extract virgin resources again. Historically, this way of building was the norm until the 20th century51. People used to recover building materials after a building was demolished, until the rise of real estate speculation in Manhattan during the twenties led to the idea of disposable buildings. When prices on land and rent started to skyrocket, the relative value of a building itself dropped, meaning it would have to be demolished within 20, 30 years to provide adequate return on investment. Compatible building systems could be a solution to increasing land values, since they facilitate shorter building lifecycles. The decreasing share of material value on the other hand, remains concerning. This problem will be addressed in chapter 4. To have the same building components used over and over, or at least be compatible with each other, they should belong to a system that is both universal (the same modules are used everywhere) and timeless (new parts and systems are compatible with older ones). One example of such an open building system dates from the sixties and was designed by the SAR foundation, who created a grid of 30 cm by 30 cm. These 30 cm is split further into 20 cm for the structure and 10 cm for nonstructural elements.

Figure 36: SAR applied to student housing la MĂŠmĂŠ52

The increase in connectivity brought by the internet has led to new building systems. Instead of the top-down approach of SAR, bottom-up collaboration has led to online platforms like Wikihouse and Openstructures. Like Wikipedia or Linux, these systems are based on a set of rules that allow anyone to create parts that can be shared with others, who in turn can adapt and improve their design.

51 52

Ta dt, Passiefge ou e Zij Tikke de Tijd o e . Image source: Galle, Ti e-Based Design, Over de Aanpas aa heid E Het O t e pe

a Ge ou e .

Again, the system starts with a grid that defines common assembly points. Individual parts are designed according to this grid and made available online. Someone can then buy these parts in a store or simply download them to be produced with the help of a CNC-machine or 3D printer. After the produced parts are assembled into components, they become part of a structure that can evolve through the exchange of parts and components with others structures. Though this system is designed to be P2P, businesses could participate as well. 3.3.3 REVERSIBLE Our desire for energy-efficient and consequently airtight buildings combined with the demand for faster construction has led to the increased use of foams, sprays, glues and similarly irreversible connection techniques. This trend makes buildings harder to disassemble, so we must resort to demolition. Modular as they may be, we cannot recuperate the bricks bonded with cement mortar (as opposed to lime mortar), since we cannot undo the bond without breaking the stones. The optimal deconstruction scenario would be the building order in reverse. Using dry, standardised connections can improve construction speed, without taxing their reversibility. The more independent the connected parts are, the easier they will be to take apart (can you install a new electricity socket, without having to disassemble the entire wall?).

Figure 37: reversible connections for a brick faรงade (left53) and concrete beam (right54), traditionally monolithic elements

We can think of a building element in terms of functional layers to help us decide which connections to make. Take an exterior wall for example. It is composed of an exterior finish, an insulating layer, its structure, a layer for techniques and an interior finish. These layers can be ranked according to their lifecycle duration. Structure generally lasts longer than skin, which lasts longer than services. Separating functional layers ensures parts stay independent in case a replacement is needed. These te h i ues a e al ead applied to i te io fi ishi g, ut a e t as o o ith ega ds to structure. Load bearing structures howeve a ou t fo a out th ee ua te s of a uildi g s ass55, mass being a good indication of environmental impact. We usually rely on cast concrete to solve issues related to fire safety, acoustics and stability. Reversible solutions for load bearing concrete st u tu es e ist, hi h should t o e as a su p ise. No ada s, ost o ete ele e ts a e (semi)prefab, only to be connected on site to improve lateral stability.

Daas Bakstee . Peikko F a e . 55 Jensen and Sommer, Building a Circular Future, 28. 53

Figure 38: building layers seperated according to their function and lifecycle

One example of reversible concrete connections was developed in Finland (see Figure 37, right). The long drying times due to the cold climate necessitated a different approach56. The result is a system of concrete walls that can be connected using steel anchors. These anchors are embedded within the o ete, so the do t i te upt the o ti uit of the o ete su fa e. Another example of reversible concrete connections was developed in the Netherlands. To address the disparity between office space oversupply and housing shortage, a floor was developed that allows future adaptation to its techniques. Instead of encasing ducts and pipes in dead-weight concrete, only the functional top and bottom layers remain, leaving a technical layer in the middle. These floors are lighter and thinner than conventional concrete floors and can easily be upgraded with newer techniques.

Figure 39: adaptable concrete floorsystem57

56 57

Jensen and Sommer, 103. Sli li e Floo S ste .

In theory most of our buildings are already reversible. With enough time and effort, we could meticulously take them apart, but this is where high labour costs become an issue. Having fewer and faster connections is what makes recuperation worthwhile. For now, only valuable elements are recuperated, while everything else gets demolished.

Figure 40: conventional connections replaced by reversible connections58

An unforeseen consequence of easier connections, is that it allows untrained and unequipped people to manipulate them. Combined with the introduction of P2P platforms mentioned above, do-ityourself building kits could lower construction costs even further. Not only would this have implications on the liability during and after construction, but more so on the role of contractors and a hite ts. If ostu e s do t ha e to el o p ofessio als fo thei housi g, e e fo of age ends up with whoever is in charge of the distribution platform. This trend could be the alternative to big DBFMO companies taking over smaller players. Whatever happens remains to be seen.

Figure 41: instructions for the E-Cube assembly59

58 59

Jensen and Sommer, Building a Circular Future, 139. Rottie s, E-Cu e , .

3.4 MATERIAL PASSPORT Despite ost uildi g p odu ts ei g i dust ialised, e a t see to appl the sa e effe ti e ess p ese t i othe a ufa tu i g se to s. Not fo the a t of te h i al skill, ut e ause e e la ki g in information. For now, the construction sector remains one of the least digitalised industries, but things are changing. In the chapter on circular eco o , e e see ho data ould ege e ate technical nutrients, like building materials. Digital material passports are used to store information about buildings and their elements to prevent devaluation over time. The regeneration, or even increase in value is pivotal to the success of the circular economy. 3.4.1 VALUE According to the circular economy, technical nutrients cannot be consumed, but remain either as valuable products, or as waste. To prevent products from becoming waste, we should design them so they (or their composing nutrients) can be recuperated, as was explained. However, building something so you can take it apart again is only half the story, effectively reclaiming the materials is the othe half. Whe e ha e o idea hat s i ou uildi gs or what properties these materials have, the fate of this building is at best a material mine. We can recuperate whatever we know is valuable, but everything else becomes scrap. This is the strategy of RotorDC, a Belgian company that salvages precious interior finishing. 54% of all construction European construction waste is landfilled or incinerated, either because it cannot be segregated or because it is toxic60. The fate of ate ials that do get e led is t u h better. Even though Belgium has a leading position when it comes to recycling of construction waste (up to 90% in weight fraction)61, most of this is basically downcycling. This is the result of our current recycling paradigm. One example is that the value of a reinforced concrete wall element is some 50 times higher per ton than the value of the gravel into which it is currently broken down when buildings are demolished. Similarly, the value of prefabricated and painted steel beams is some 30 to highe pe to tha the pu e etal alue 62. To prevent the devaluation through the loss of information, every building element should be identified with a material passport, that stores information such as: • • • • • • •

Who owns this element? (not as obvious when different companies provide services) What is its histo ? o igi , p e ious o e s, upg ades, … How can it be (dis)assembled? What is its status? o ito i g deg adatio , use, … What are its composing materials and their values? (both biological and technical nutrients) What is its environmental impact? (LCA) …

Growth Within: A Circular Economy Vision for a Competitive Europe, 20. Jensen and Sommer, Building a Circular Future, 12. 62 Jensen and Sommer, 26.

Figure 42 summary page of a material passport63

When we retain information about an element, its value should increase, rather than decrease. As Tho as Rau puts it, e should ite do , i stead of ite off . Si e esource prices are on the rise, the value of building elements should increase as well. Instead of a material mine (scrapping and recycling valuable elements), or a material depot (reversible design, but without the retention of information), we get a building as a material bank or BAMB (temporal storage of elements whose value increases). We can think of it this way. If a building were a vault, the way we currently handle its end of life is ith a sti k of d a ite. Si e e do t k o the o te ts of the ault, e a t k o its alue. Paying for a locksmith would be too expensive, so we use the dynamite to blow up the vault, damaging the contents in the process. A material passport would the equivalent of having a registry containing the codes to open the vault and a description of the content and its value.

material mine

material depot

material bank

Rotor DC

Alliander HQ

De Fire Styresler

Figure 43: progressively increasing value64,65,66

Ne Offi e Buildi g . Image source: Roto De o st u tio â&#x20AC;&#x201C; Reuse of Buildi g Mate ials Made Eas . 65 Image source: Lia de - RAU . 66 Image source: Jensen and Sommer, Building a Circular Future, 37.

3XN applied the BAMB p i iple o thei desig of de F e St esle , a â&#x201A;Ź illio offi e uildi g. Half of this value originates from the superstructure. Through the use of reversible design and ate ial passpo ts, the added a additio al â&#x201A;Ź , illio to the esidual value of the superstructure, about 4% of the total cost of the building (the additional economic value for the interiors and the electrical/mechanical systems was outside the scope of their study). If we consider only the superstructure and envelope, the e t a alue o espo ds to a out , % of thei e uilt alue i current prices and double the amount by 2065 (the intended end of life for the building)67. 3.4.2 EXCHANGE This begs the question: who is responsible for a building element and its material passport? Should it be the supplier, who might go bankrupt. Or perhaps the building owner, who is now charged with the management of complex data? There is always the risk that the involved suppliers or users are no longer around, once an element reaches the end of its use phase, because of their long lifespan. There are cases where, in spite of their reversible design, adaptable buildings were demolished and their materials disposed of because the involved actors had disappeared. One way to circumvent this problem would be to introduce a third party, the trustee. Third-party financing works as follows: The producer wants to offer a product as a service, but does t a t to take a isks. The use a ts a se i e ut a ot pa a la ge su up f o t. The solution to this stalemate is the financial trustee. A bank can act as a trustee and collects periodic payment from the user, in exchange for the initial investment. This way the financial security of both parties is guaranteed.

Figure 44: third-party-financing facilitates product-service business models68

Another way of providing secure transactions would be through the use of a blockchain. The blockchain is an incorruptible digital ledger of economic transactions that can be programmed to e o d ot just fi a ial t a sa tio s ut i tuall e e thi g of alue. 69 The main advantage over third-pa t fi a i g is that a lo k hai does t e ui e a iddle a to se u e a t a sa tio ut relies on a decentralised computer network. How blockchain exactly works would lead us too far, but the concept is simple enough.

Jensen and Sommer, 255. Image source: I fog afieke - Vlaa de e Ci ulai . 69 Tapscott and Tapscott, Blockchain Revolution. 68

Some blockchains, such as Ethereum, can be used to verify a transaction of information, such as cryptocurrency, records or contracts, just like a bank would. The blockchain version of a contract is alled a smart contract a d it sto es a pa e t i a lo k u til a e tai e ui e e t, the se i e, is met. If this condition is met, transaction is ensued. If not, the payment is returned. This might sound like science fiction, but smart contracts are already being used to execute real estate transactions. In Georgia there have been 1,2 million succesful property registrations since April 2017 that use this technology70. But how does a building element make its way from one building to another? When building materials are ready for their next life, they should be retrieved before they can be used again. This process is called reverse logistics. When an element is demounted, it has to be identified before it can be retrieved by its supplier or stored in a warehouse. This is the main benefit of using a material passport: to facilitate the reverse logistics chain that enables the reuse of technical nutrients. Next, the element is collected and returned to a material stock. Here an element reaches the interim phase, the period between two use cycles. The stock can either be passive (materials are returned to a second-hand storage warehouse) or active (materials are recovered by their suppliers). The active recovery of building elements by the supplier is the preferred scenario, since the risk at loss of information is minimised. Another application of blockchain technology mentioned earlier, lies in its ability to store records, such as material passports. A decentralised storage of data would prevent any information from being lost, safeguarding the value of the building element, even in a passive stock.

Figure 45: reverse logistics71

3.4.3 MONITORING If parts of a building are to be reused, we need assurance they will perform as expected. Uncertainty about the stability of a structural element is unacceptable. Rather than manual inspection, other ways of active and passive monitoring can be employed to verify their condition. An example of a passive verification method is a strain gauge, a thin film that indicates if concrete has been stressed. If we periodically measure the thermal resistance of a wall element, we can tell when the quality of the insulating material degrades. This is called active monitoring.

70 71

Fi a iĂŤ estudee t i oe i g lo k hai ij aa koop huis . Image source: I fog afieke - Vlaanderen Circulai .

We can also imagine a passport for a building, rather than for an individual element. This building passport could contain information on: • • • • •

The elements that are part of the building and by extension their material passports. Its environmental impact or LCA Its co su ptio a d p odu tio of e e g , ate , se age, … Its occupancy rates …

Figure 46: material passport versus building passport72

Nowadays, most buildings already have some form of passport containing information on their owner, location and energy profile. The Flemish government has recently introduced a building passpo t alled o i gpas , that o i es the diffe e t e tifi ates a o e eeds to sell o renovate their house. A possible benefit of a building passport could be its potential to monitor the water and energy o su ptio i a uildi g. Though these a e t uildi g ele e ts e essa il , thei o su ptio is elated to a uildi g s desig o e o utilities i the follo i g hapte . Buildi g passpo ts could drastically improve resource efficiency. Until now, everyone from architects to owners, to politicians ha e elied o h potheti al data to i fo thei de isio s o hat is sustai a le a d hat is t. We use mathematical models based on parameters like insulation thickness and building volume to al ulate the e e g pe fo a e of a uildi g, ut e a e a el o f o ted ith a uildi g s eal consumption of primary energy. The next figure compares the actual and theoretical gas consumption of Dutch dwellings. As we can see, the difference between high and low performance housing is a lot smaller than anticipated.

Ne Offi e Buildi g .

Figure 47: actual and theoretical gas consumption for different energy lables73

This is a typical example of the rebound effect, where improved resource efficiency increases consumption, rather than decreasing it. Measuring resource consumption could make us more aware of our behaviour and consequently help limit our impact. One way to do this is by addressing the economic benefit of saving electricity. Once we see how much power our fridge actually uses, we might be incentivised to invest in a more energy-efficient model. E o o i i e ti es ho e e , a e t al a s effe ti e. Not e e o e is i te ested i sa i g a fe euros if it ea s the ha e to tu do thei heati g. A d hat a out people ho do t pa thei o e e g ills, like i hotels, u si g ho es, stude t housi g, â&#x20AC;Ś A UCLA project called Engage, studied what motivates us to save energy, by installing smart energy meters in student residences. Providing real-time feedback combined with different personalised messages led to surprising results. Some students got messages telling them how much money they saved, others on the health effects of emissions, others yet on their environmental impact. Even though participants claimed their reasons for saving were mostly financial, data showed that messages on the economic benefits had no impact on their behaviour. Messages explaining how energy consumption increases the risk of asthma among kids, led to an 8% decrease (up to 19% in households with kids). The biggest impact was when the researchers introduced social competition to the mix. When households were compared to their neighbours and rewarded with messages complimenting them for their good behaviour, energy consumption dropped an astounding 20%74. This strategy of competition and reward can also be applied to other social groups, like companies or neighbourhoods. Some companies give their tenants an energy-budget they can exchange or gift, increasing social cohesion. Maj e , Ita d, a d Viss he , Theo eti al s. A tual E e g Co su ptio of La elled D elli gs in the Nethe la ds . 74 Vox, Why Humans Are so Bad at Thinking about Climate Change.

Figure 48: engaging people to conserve energy by monitoring their behaviour75

The combination of big data and behavioural design could prove to be more effective than simply relying o effi ie t te h olog . This o fi s e e ot just a ti g as ho o e o o i us , ut as so ial eatu es. Usi g desig to i flue e ou eha iou o nudging , a help us edu e ou i pa t. People tend to use the stairs, rather than the elevator, when they are clearly marked or have an i te esti g desig . The Bullit Ce te s i esista le stai e ou ages a health lifest le, de eases elevator waiting times and cuts back on energy use.

3.5

CONCLUSION In this chapter we explored how a building and its elements can be designed, constructed and maintained in a circular fashion, and how this differs from the current building practice. Our first conclusion is that the building sector is woefully outdated, resulting in a wasteful and generally unsustainable building stock. Taking lessons from more industrialised and digitalised sectors could help us improve on this. Applying the circular business models described in the previous chapter allows us to reframe this situation. The systematised design and assembly of building elements (IFD) makes it possible to adapt and demount a building according to its changing needs. Including suppliers, building occupants and facility managers in the design process (LBC) would shift the design focus from building completion to its entire lifecycle. The use of building data and construction simulation (BIM/VDC) facilitates collaboration among stakeholders and optimises the building process. The goal of a circular building is to regenerate and increase its value. We can achieve this by designing it in an adaptable way and storing its information in material passports. Both of these desig st ategies o i ed, akes the uildi g s ele e ts eusa le a d gi es us hat is k o as a Building As Material Bank or BAMB. Building adaptability is the result of scenario development,

Che , Del as, a d Kaise , Real-Time, Appliance-Le el Ele t i it Use Feed a k S ste

element compatibility and reversible connections, while material passports are used to store element value, facilitate element exchange and monitor resource consumption. Scenario development is considering the probable evolution a building demands over its lifetime, and finding a fitting layout of structure, techniques and circulation. Calculation of environmental and fi a ial osts o e the uildi g s lifeti e LCA), can inform us whether a support-infill is preferable, or a kit-of-parts. Compatibility forms a framework for different designs that makes elements interchangeable. This framework provides a set of rules, usually in the form of a universal grid, that determines modular dimensions and connections. Reversibility is the ability of connections to be undone, usually a property of dry, mechanical joints, rather than wet, chemical bonds. Thinking in terms of functional layers ensures parts stay independent in case they need to be replaced. Material passports store information about a building and its elements, such as their contents, who owns them and how they can be disassembled. This makes sure their value is retained and can even increase over time, turning a building into a material bank. Third party financing facilitates the product-as-service contract between suppliers and users. Verifying if contract requirements have been met is another function of the material passports. At the e d of a ele e t s life, it is etu ed to the supplie i hat s alled the reverse logistics chain.

Figure 49: imagining Asterdam's circular construction industry76

De elopi g a Road ap fo the Fi st Ci ula Cit : A ste da

Finally, a material passport is used to monitor a uildi g s esou e o su ptio a d p odu tio . This insight can better help us understand how buildings are used and inform its users on their behaviour. The future role of architects needs to be redefined. If buildings are conceived as adaptable configurations of standard building components made of building kits, designing and constructing buildings can become accessible to more stakeholders, not only architects. If the construction and real estate sectors want to keep up with these disruptive technologies, they will have to evolve. Traditional architect offices will have to adopt data-analysts and product developers, or it will be the other way around.

4 Urban Metabolism

A e dless u

er of gree

uildi gs does â&#x20AC;&#x2122;t

ake a sustai a le ity

Jan Gehl

In this chapter we will expand the scope of circular building to the level of the city. We look at the interaction between a building and its environment through the lens of several key resource flows such as energy, water and mobility. Fi st, e ll go o e the i pa t of the i easi g u a isatio o ld ide a d the i po ta e of ities in a struggle for sustainability. Then we will discuss the different technical systems present in buildings and how their dependency on an external infrastructure can be limited. Finally, we explore the different resource flows in a city and how these can regenerate each other.

4.1

URBANIZATION Since 2008, over half of the world population lives in cities. This urbanisation shows no signs of slowing down. Quite the contrary. The United Nations recently projected that nearly all global population growth from 2017 to 2030 will be absorbed by cities77. The o ti ui g u a izatio a d o e all g o th of the o ld s populatio is p oje ted to add . billion people to the urban population by 2050, pushing the global urbanisation rate over 66%. Europe is already on the verge of 80% urbanization. While the expansion of cities is impressive, the city slums grow at twice that pace. Without considering other socioeconomic factors that contribute to this issue, the current building sector is unable to keep up with urbanisation, leaving 2 out of 3 urban inhabitants living in slums by 2050 as a result. Ways to address this lack of productivity were presented in the previous chapter.

Figure 50: global urbanization78

Currently cities take up about % of the o ld s la d a ea79, while they account for: • • • •

75% of all resource consumption 50% of all waste production 80% of all emissions 80% of worldwide GDP

Figure 51: a city's resource flows80

Cohe , U a izatio , Cit G o th, a d the Ne U ited Natio s De elop e t Age da , . Attia, Haiti s Re uildi g -- The La ge Pi tu e . 79 Delva, Buiksloterham circulair. 80 Image source: BIOPOLUS .

This immense growth puts cities under a lot of pressure from several directions. First of all, they are more sensitive to the effects of climate change. Most global cities are situated near the oceans, making them prone to rising sea levels. Even Europe, which has the means to cope with these scenarios, would suffer if global temperatures were to rise81. Southern Europe in general would see the biggest overall increase in temperature (worst specifically in Rome and Stockholm), resulting in dramatic draughts pushing cities like Malaga and Almeria to the breaking point. Similarly, central European cities in general would experience more frequent and intense heatwaves (worst specifically in Prague, Vienna, Lisbon and Madrid). Meanwhile, North-western Europe in general is facing worse floods due to rising river levels (worst specifically in Dublin, Helsinki, Riga and Zagreb).

Figure 52: climate change affecting European cities82

Cities are unable to accommodate the traffic generated by their inhabitants, resulting in congestion. The economic consequences are immense. Time lost in traffic cost 2% of GDP in many cities83. All this traffic leads to pollution, which decreases air quality. Approximately 80% of urban areas have air pollution levels that exceed the World Health Organizatio s li its. These o ditio s ha e ad e se effects on cities that go beyond the direct impacts on human health; for example, in China, studies have shown that low air quality is undermining city competitiveness and is leading to a significant brain-drai f o Chi a s la gest ities84. Megacities around the world are struggling to provide basic infrastructure under the pressure of growing demand. 125 of the largest 500 cities worldwide are experiencing water stress in some way

Gue ei o et al., Futu e Heat-Wa es, D oughts a d Floods i Eu opea Cities . Image source: MAPS | E i o e tal Mig atio Po tal . 83 Growth Within: A Circular Economy Vision for a Competitive Europe, 20. 84 Cities i the Ci ula E o o .

or another85. Many cities have outdated infrastructure, contaminated sources, or simply not enough ate to fill thei ese oi s. The ostl i po tatio f o outside the ities te ito leads to a sha p increase in drink water prices. Today 3.4 billion people suffer from water shortage and by 2030 demand for fresh water will exceed supply by 40%. Yet despite decreasing liveability, cities keep attracting more people, accumulating more wealth. At the heart of creativity, innovation and growth, cities play a central role as motors of the global economy, allowing them to wield more political influence.

Figure 53: the economic power of global cities86

4.2 EARTHSHIPS Ba k to uildi gs. Ne t to those esou es that a e pe a e tl pa t of a uildi g, ou tless othe resources are temporally entwined with a building. In the previous chapter, we discovered those stati o st u tio ate ials a e o e d a i tha e pe ei e the to e. Still, thei life le is on a timescale of months and years, rather than days or hours. The temporal resources we are talking about are less rigid, more flowing. Energy, in the form of heat or electricity, is one of those. A building depends on a network to supply these flowing resources. Consequently, the sustainability and value of a building depends largely on external systems. I a a , a uildi g s te h i ues itigate its sho t o i gs. It ight e ell i sulated, et additio al heating is required. It makes the most of daylight, yet artificial light provides visual comfort. For adequate air quality, we need a HVAC-system, etc. With enough technical installations, a building 85 86

The Cities Most Likel to Ru out of D i ki g Wate . Flo ida, Whe Cities A e Mo e E o o i all Po e ful Tha Natio s .

could become entirely self-sufficient and function off-the-g id. We all these uildi gs earthships , analogous to spaceships, since they are also self-contained.

Figure 54: the Bullitt center is self-sustaining water and energy wise87

One example of such an earthship is the Green Solution House conference centre and hotel on the Danish island of Bornholm. Not only is the building designed for disassembly, but the resources it consumes on a daily basis are (re)generated on-site. Photovoltaics produce energy, rainwater is collected and used water is biologically cleaned and reused, integrated greenhouses produce organic fruits and vegetables for the hotel restaurant and the daily material flows from running the centre are either recycled or composted. Finally, the foundation reinvests all earnings back into the centre, which makes it a project under continuous development. We can push this o ept to the e t e e a d thi k of a uildi g s ai suppl i a losed s ste , o air enters or leaves the building. Air cleaning is a new concept that goes beyond heat recovery and can be used to improve poor air quality. While usually the supply of fresh exterior air suffices, extremely polluted metropolitan areas like Beijing might benefit from air quality improvement. This might sound like an exceptional situation, yet many European regions suffer from similar conditions. It is estimated that on average, people of Fla de s life spa de ease ea s due to e posu e to anthropogenic fine particulate matter.88 Our first impression could be that these solutions are anti-urban. Instead of being part of a greater system, earthships are self-centred, individual entities. Even though these integrated technical solutions are commonly used in more remote areas, they can be applied in more urban environments as well. Buildings that are self-sufficient are less dependent on expensive external infrastructure, without weighing down an already overburdened system. Suppose every building generated some resource and exchanged these with other buildings in return for different resources? Instead of externalising every problem, every building would contribute to an urban network. More buildings would generate more resources and allow for greater connectivity and collaboration. This pushes the idea of a sustainable city beyond the usual discussions about building typology and density.

87 88

WA, Bullitt Ce te . The GAINS Model - IIASA .

4.3 A WEALTH OF FLOWS 4.3.1 THE CIRCULAR CITY Circularity of the built environment is being explored and developed on a building scale, but its application on an urban scale is a more recent endeavour. Cities could be uniquely positioned to drive a global transition towards a circular economy, with their high concentration of resources, capital, data, and talent over a small geographic territory, and could reap significant benefits from the outcomes of such a transition. In the coming decades, cities play an important role in the transition to a circular economy as even greater rates of urbanisation are expected, and significant infrastructure investments will be made. How does a circular city work? Rather than a machine, designed to fix problems in the most efficient way possible, think of it as a complex metabolism. Every system grows and influences the others, working with complexity, instead of against it. Mobility impacts space, waste impacts energy and vegetation impacts water. A circular city can adapt to changing conditions over time. This requires a holistic approach, all systems in symbiosis with one another, combining effectiveness (doing the right things) with efficiency (doing things right). Too little effectiveness leads to a brittle system, while not enough efficiency leads to stagnation. The right balance between both leads to a resilient and streamlined system. As we will see later, energy networks are one example of where we have to balance effiectiveness and efficiency.

EFFICIENT

EFFECTIVE Figure 55: types of networks89

To make these concepts more tangible, these excerpts90 describe a day in the circular city: â&#x20AC;&#x153;O e ou e do e ith eakfast all the lefto e s, i ludi g the pa kagi g of the food, go st aight into the bio-waste chute, where it de o poses a d e o e fe tilise fo the o u it ga de . Si e the eathe is t that nice, you decide to skip biking to the train station and instead order one of these self-d i i g, ele t i po e ed a s You ate ial a ketpla e o has e plo ees, but since everyone travels so much, or often prefers to work remotely, it makes no sense to keep 18 desks standing empty most of the time. Not to mention the rent and bills costs. So you share an open office space of 30 desks and five meeting rooms with th ee othe o pa ies. 89 90

Blo k hai a d E o o i De elop e t . Vol, Futu e of Cities .

Gi e the a e f e ue ou ha e eed fo house tools, it s o e ie t that ou o u it e t e has a local tool library where, for a small fee, you can borrow a good drill, saw and a hammer for a ouple of da s. Just efo e goi g to ed ou he k the e e g fo e ast fo to o o . Good e s – it looks like low e e g o su ptio is e pe ted i ou eigh ou hood 4.3.2 DIGITALIZATION O e of the flo s e did t dis uss et, is the flow of information. Yet this might be the most i po ta t esou e of the all, fa ilitati g the i ulatio of the othe s. If a i ula it is a metabolism, the digital network is its nervous system. Digitalisation facilitates a circular economy through virtualization, control over material flows, and new ways of interaction between government, businesses and citizens. These interactions range from P2P networks, to monitoring service contracts between consumers and providers. The collection of data can identify wastefulness and enables people to make informed decisions. The following digital technologies in particular can enable a smart city: •

•

Asset tagging: tagging technologies can provide information such as the condition and availability of materials. In turn, this information can help extend their use of an asset and regenerate atu al apital. Fo e a ple, due to leakages i Fla de s ate ai s illio lit es of drinking water is lost daily. The financial cost amounts to 280 million euro every year. Using sensors to verify network integrity could reduce this loss, limiting costs and environmental impacts. Material passports are one example of asset tagging. Geo-spatial information: When combined with asset tagging, geo-spatial information can provide visibility on the flow of materials, components, products and people across the city. One application is optimising traffic routes to mitigate congestion based on real-time information Big data management: Leveraging advanced processing capacities, computers can now analyse complex data more quickly, overlaying human behaviour with information based on asset tracking and geo-spatial mapping. An example would be balancing energy demand peaks and valleys by predicting weather conditions and energy consumption patterns at a local level. Connectivity: the widespread access to the internet through the use of computers and smartphones increased the connection between people. It makes information more accessible and transparent towards end users but also enables circular business models such as leasing and P2P (peer-to-peer) sharing platforms by facilitating take-back systems.

Some things to consider in the face of the digital revolution: •

•

Monitoring and measurements gain more importance and play a major role in decision making processes. However, raw data by itself gains us nothing. It needs to be analysed and interpreted to become useful. Sensors and data technology are becoming more accessible, both financially and in application. Still, we have to assure this technology is to the benefit of everyone, without marginalising those without the means to participate. Otherwise, sustainability is devoid of humanity. Right now, collaboration remains unfeasible because of limited interaction between different parties. Releasing open data on sharing platforms allows developers to create useful applications. In London for example, public transit companies shared its data. As a result, 42% of Londoners use an app that was developed based on open data.

â&#x20AC;˘

Network transparency and data protection become more important as connectivity increases. When responsibility gets separated from power, consumers get the short end of the stick. Their data is mined for the benefit of providers who remain untouchable.

The way we handle this digital revolution will decide whether it will help us solve our problems, or actually make them worse. We can be sure of one thing, we are becoming more and more dependent on it, and there are no signs of it slowing down. The following graph demonstrates the spectacular growth of several sharing platforms, often monopolies in their respective markets.

Figure 56: growth and funding of the P2P economy91

More often than not, these platforms overshoot their goal to provide authentic experiences while increasing the use of assets. The opposite might be true. Rather than sharing a ride with someone who, by chance, is going the same, Uber has become the biggest taxi service worldwide, without owning a single vehicle, thus avoiding any legal responsibility. Instead of decreasing emissions through greater efficiency, private transportation is encouraged. On top of this, these unregulated vehicles are more polluting than their taxi counterparts. If we replace taxis with hotels, we get the exact same story for Airbnb. To summarise, cities and their inhabitants are facing the challenge of a rapid urbanisation, while holding the key to turn this to their benefit. Due to their concentration of resources and people, dense cities are the ideal breeding ground for a circular economy while also benefitting greatly from digital technologies to enable this transition. These developments impact the city in turn, fuelling the ongoing urbanisation, which creates a positive feedback loop.

URBANIZATION

DIGITAL REVOLUTION + CIRCULAR ECONOMY Figure 57: the positive urbanization feedback loop

4.4 SPACE Our cities are sprawling, whether they are being scattered over large territories, or keep growing layer upon layer like an onion. As our cities keep growing, they swallow up ever more land, that can

Image source: I fog afieke - Vlaa de e Ci ulai .

no longer be used for agricultural purposes or as natural landscapes that provide us with fresh air and water. I Belgiu , % of the populatio li es i u a a eas92 (coming in 7th in the worldwide ranking, behind countries like Monaco and Singapore). 32% of Flanders has been built upon. There is hardly any space left, yet in Flanders, open space disappears at a rate of 12 football fields a day, nearly all of it to housing93. We usuall do t thi k of spa e as a esou e, e ause of its unchangeable nature. We can think of it this a : the uildi g s site is its ost lo g-lasting parts. Occupants and buildings are mobile, but the la d e ai s. We do t o su e it like e o su e ate o e e g , e e el o up it. But, o e we build upon it, it cannot be used for something else. In a way that makes land the most limited resource. While energy and water can transform and loop, ea th s su fa e is fi ite. O e e sta t keepi g t a k of all la d i a adast e, ho s the o e a d what s it o th, its alue sta ts i easi g. The de a d fo housi g keeps i easi g, et the suppl of land remains unchanged. That is the main reason why property becomes more expensive: a house depreciates, but land appreciates.

Figure 58: property value increases even when construction price remains similar94

Yet e a age ou li ited spa e e poo l . While the e s a a ute housi g sho tage, a of ou buildings stand empty7. In Europe 60% of office space is underused, even during working hours. 35% of all homes are under occupied, while 17% is overcrowded. When we consider the lowest 60% of incomes, this overcrowding rate rises to 30%. It s ot just that ou housi g is t e e l dist i uted, our cities cannot adapt fast enough to a mobile population whose needs keep changing. This inability to adapt has some dramatic consequences. As of 2018, the Netherlands is suffering from a shortage of 200.000 homes95, while over 5 million mÂ˛ of office space is vacant96. This surplus and shortage does t exist at different places in the country, but overlap in the major cities like Amsterdam, Rotterdam, The Hague and Utrecht (see Error! Reference source not found.). U a izatio Cou t . Ve kla e de Fa to e i de E olutie a Het Rui te eslag > Rui te Vlaa de e > Studies - Ruimtelijke O de i g . 94 Ke dall a d Tulip, Supple e ta I fo atio | RDP 8- . 95 S ijde s, Wo i gteko t e eikt hoogtepu t i . 96 Leegsta d a Ka to e -2017 - PBL Pla u eau Voo de Leefo ge i g .

Figure 59: a static built environment leads to overlapping shortage and vacancy

4.4.1 ADAPTABILITY How can we design space to be more resilient and responsive to change? Most strategies presented below are similar to the ones we discussed in the previous chapter under building adaptability. 1. Spatial organisation: Keep subdivisions limited, by compacting and optimising infrastructure (roads, parks, power stations,). Subdivision leads to sprawl and limits future development. Less infrastructure means less financial and environmental impact, while compactness means development can happen all at once, instead of one at a time.

Figure 60: concentrating motorized transport increases public space97

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2. Multi-purpose space: More general spaces allow for different kinds of activities. When a certain function is no longer required, the space can take on a different function. This means it can be used more frequently so its value (and the value of the surrounding buildings) remains. For many restaurants, empty spaces can be transformed into affordable working spaces during the day. Wi-Fi, desk space and basic amenities can be provided in return for financial benefits and costumer attraction. Spacious is a US startup connecting empty restaurant spaces with people looking for a prime working location around New York or San Fransicso. A app e a les Spa ious usi ess odel to o k o e ti g use s ith the ea est lo atio with available space.

Figure 61: multi-purpose space98

3. Functional diversity: Co i i g diffe e t fu tio s o housi g t pes i ease a eigh ou hood s ohesio . I stead of a sleeper town that only functions at night, or a tourist city that lives for the holidays, mix living, working and playing. Even a single building can house a different function on its street level and on upper floors. Teleworking takes this idea to the 21st century. You o lo ge ha e to go to o k, let the o k o e to ou. This ki d of i tual o uti g would drastically reduce traffic and its related costs. 4. Space for the long term: Anticipating on future developments make things easier in the long run. Rather than having to expand an existing neighbourhood, redundant design allows for potential transformations to grow naturally from the inside out.

Figure 62: Static layout versus anticipatory layout99

Image source: Padua t et al., Casestud o t e p a ge ou e i fu tie a aa pas aa heid: Mahat a Ga dhi ijk Me hele . 99 Image source: Paduart et al. 98

5. Reuse The usual reaction to a demand for more space is usually to build more. Rather than starting from scratch, adapting an existing context can yield several benefits. From renovating existing heritage, to the recuperation of old materials, reusing old elements means fewer financial and environmental costs. 4.4.2 PROPERTY Many homeowners consider their property to be a long-term investment, often financially stimulated by the government as an alternative pension/retirement plan. People hold on to small snippets of land, with the intention of passing these on to their children, without ever developing them. Add to that the restrictions on housing density and the result is a fragmented and underdeveloped territory. On the other hand, we have the big cities, where limited area is ramping up property value. Especially in the downtowns of major metropolitan areas, where the home value can exceed the replacement cost 5 times over (i.e. Land versus construction value). The limits on density exclude people that are able to pay for construction but cannot afford the land. In both cases, the limits on housing supply leads to troubling scenarios. Both expensive metros and sprawling town would benefit from the relaxation of restrictions on housing density, but for different reasons. Greater density in the city can mitigate housing shortage, whereas in expanding villages it can prevent sprawl.

Figure 63:New York home value to replacement cost ratio (2016)100

But does t i easi g a lot s de sit aise the alue of the la d? The i eased la d alue is ot the result of dividing the same land over more units, but having a fixed number of zoned units for an increasing population. The value of land depends on several characteristics, amongst those the nu e of u its it is zo ed fo . Upzoning ill thus i ease the la d alue, ut also i eases the number of homes allowed on the market, decreasing their scarcity.101 100 101

Image source: Ro e , Pa i g Fo Di t: Whe e Ha e Ho e Values Deta hed F o Romen.

Co st u tio Costs?

Upzoning one area (perhaps an attractive location near the city centre), but not another (the fringes of suburbia) is not fair towards the property owners. To keep the total amount of housing in check, one solution might be a TDR or transfer of development rights. A location unsuited for densification is dezoned, while a more desirable location is upzoned. The increased value is distributed among both owners. This is beneficial to all parties while freeing up space and decreasing environmental impact. As e e discussed earlier, the reason this land value appreciates is not because of the property owners. The increased value is the result of external factors, like investments in public infrastructure, or proximity to businesses. Major infrastructure projects around London, like Crossrail 2 and the Bakerloo tube line extension are estimated to cost the public £36 billion. Landowners, meanwhile, will pocket £87bn from increased land values nearby102.

Figure 64: transfer of development rights103

Wh should t the o u it e efit f o its olle ti e effo ts? This is possi le if e sepa ate construction value and land value from each other. A Community Land Trust, or CLT, allows exactly that, for someone to own a house, but not the land it sits on. Like with a lease, the homeowner merely uses the land owned by a trust. When the homeowner decides to move, he keeps the added value of the house, while the land returns to the trust, together with its added value. The trust, often the city itself, invests in better infrastructure which further increases the land value. Disconnecting land and construction also means lowering the costs for buying a house, since it is no longer tied to land value. We can go a step further and forgo ownership altogether. A DBFMO, one of the business models we discussed in chapter 2 chapter, means ownership remains with the developer, who provides a uildi g as a se i e to its o upa ts. I stead of o i g a offi e that s o l useful half of the ti e, workers could rent a workplace for as long as they need it and share office amenities with other companies. 102 103

Colli so , House P i es A e t the Issue – La d P i es A e . Va B oe k a d Bogda , De Vlaa se kli aattop op ap il

One could always rent their home, but their capital would diminish over time, without getting anything for it in the long run. And yet, renting is becoming the most common form of acquiring a home in the city. In Gent, over 50% of the inhabitants rent, instead of buying. Half of those who rent, spend more than 1/3rd of their family budget on housing. A housing cooperative combines the benefits of ownership with the freedom of renting. One becomes a member of a housing cooperative by buying a share of the company that owns real estate. Once a member, a person pays a monthly rent and in return is granted the right to occupy a housing unit. But the member is still a shareholder in the company that owns his house, so is entitled to his share of the profit, a dividend which is deducted from the rent. The shareholder also gets to decide what happens with the pooled resources. Maybe invest in solar panels, or a shared car. Agency o e o e s ho e is the se o d ad a tage housi g oope ati es ha e o e egula e ti g. A CPC or Collective Private Commissioning is similar in concept, but different in execution. Usually, a multi-family home (like an apartment) is constructed via a developer, without the intervention of the intended owners. In a CPO, several would-be owners pool their funds and assign a contractor, cutting out the middleman in the process. This way, the owners are involved in the design of their individual unit, but also the common areas. I stead of the t aditio al di isio et ee those ho ha e p ope t , a d those ho do t, e get a spectrum of different ownership models, allowing for more flexibility and distributed control of valuable real estate.

RENT

COOP

DBFMO

CPC

BUY

Figure 65: degrees of property ownership

4.5 URBAN BIOCYCLES Compared with the technosphere, the opportunities for shifting the biosphere towards a circular model have so far been largely unexplored. This results in several problems, with the interaction between cities and their territories at its root. Cities concentrate biological materials and nutrients f o u al a eas, ut do t etu these to the atu al s ste s. This i ala e et ee i flo s a d outflows leading to natural resource depletion and waste accumulation in cities. Currently, a lot of food, water, nutrients and energy are lost. To name a few examples104: • • • • •

104

About a third of all food produced globally is wasted each year. The volume of greenhouse gas emissions this produces is ranked third behind China and the US. While soil degradation leads to decreasing yields, food demand is expected to rise 50% by 2030. Farming takes up 40% of all land area in the EU and accounts for 70% of water consumption worldwide. Nutrient run-off and impervious city surfaces are polluting and lowering our water tables thus endangering our fresh water reserves. Decreased urban green adversely affect liveability and resilience to climate change.

Walke , U a Bio

les ,

4.5.1 WASTE Not only is waste management a costly affair, it is also a major environmental burden105 (solid waste alo e auses % of all glo al e issio s. A o di g to the i ula odel, this aste is eall a esou e that is t used. % of all solid aste is o ga i a d a e o posted o a ae o i all digested. However, most of it ends up in landfills, generating 12% of all methane emissions. Wastewater is the largest untapped waste category, as big as all solid waste categories taken together. It is 95% organic, but only 10% of its nutrients are recycled. The rest usually ends up in natural water bodies, causing damage to aquatic ecosystems. Organic nutrients are not returned to the soil. Instead, the EU imports 92% of its phosphorus to produce synthetic fertilizer106. All while global phosphate reserves (the mineral used to make phosphorus) are dwindling, lasting only 80 more years. A circular approach to phosphorus is to close the loop between food, people and soils. In theory, the recovery of 100% of the nitrogen, phosphorus and potassium in all organic waste streams would be enough to replace all chemical fertilizers nearly 2,7 times.

Figure 66: Amsterdam's potential biocycle107

Recovering nutrients from wastewater could be the most efficient way to do this. Wastewater can be viewed as a rich soup of energy, carbon, nitrogen, phosphorus and other ingredients that yield different products the most valuable being water, which can be reused or safely returned to the biosphere.

105

Walker, 13. Walker, 21. 107 De elopi g a Road ap fo the Fi st Ci ula Cit : A ste da 106

A a al sis of A ste da • • • • • •

ual aste ate p odu tio de o st ates its potential value108.

Water – 72 million cubic metres Organic matter – 40,041 tonnes Phosphorus – 577 tonnes Nitrogen – 4,140 tonnes Heavy metals – 28.8 tonnes Pharmaceuticals – 3.1 tonnes

The e a e se e al app oa hes as to ho aste ate a e e led , depe ding on which moment in the wastewater process the recovery happens. This can be either at building level, at neighbourhood level, or at territory level. At a building level, water and energy consumption can be reduced by first separating black, grey and rainwater. A common method of rainwater harvesting is rooftop harvesting. Most roof covering (tiles, metal sheets, plastics, solar panels, but not grass) can be used to intercept the flow of rainwater and provide a household with water for gardening, irrigation, even quality drinking water and year-round storage.

Figure 67: zero wastewater with energy and nutrients recovery109

108 109

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Black water is rich in organic matter and is contaminated by pathogens. It can originate from toilets, but also garbage disposal units (a shredder installed underneath the kitchen sink). Operating a vacuum toilet requires less water (toilets take the largest share in domestic water consumption) and simultaneously results in a drier waste stream that can easily be composted. Going above and beyond, urine diverting toilets are completely dry and separate solid waste from urine (which is ste ile a d o tai s ost of ou aste ate s ut ie ts, ut o l akes up % of its olu e . The Grey water stream contains all the other wastewater. Once treated it can be reused for many purposes, potentially even as drinking water. Its most common applications are irrigation, toilet flushing or heating. As grey water is often heated (around 25Â°C), it contains a lot of energy that can be recuperated as it flows through a DWHR or drain water heat recoverer. The o i atio of these diffe e t te h i ues is alled ze o aste ate e o e a d is al ead ei g i ple e ted toda , i the Nieu e Dokke example.

ith e e g a d ut ie ts de elopment (Ghent) for

On a neighbourhood level, basic resource streams such as water, energy, food and organic waste can be integrated in a metabolic hub. A single metabolic hub can serve a population of about 10-20.000 people. These decentralized units serve as a platform that converts incoming waste streams into useful resources. The treatment process uses bacterial colonies that are optimized using digital feedback. Conventional waste treatment is usually an energy intensive process resulting in high operating costs. The more efficient bacterial treatment (35% lower energy costs), combined with the production of food, water a d io he i als iogas, fuel, fe tilize , â&#x20AC;Ś , t a sfo this i to a et-positive process. Instead of a smelly problem that is est kept at a dista e, a hu s p odu ti it akes it o e i teg ated i to the urban fabric.

Figure 68: metabolic hub on a neighbourhood level110

Fi all , o a te ito ial s ale, a it s la out a d topog aph a eate a s iosis between urban 111 a d u al a eas. Take AWB s aste pla fo Ista ul s g o i g populatio . Instead of having the city sprawl out radially, endangering valuable natural assets, they propose a holistic solution. By

110 111

BIOPOLUS . Atelier Istanbul: ArnavutkĂśy.

, Ista ul s populatio ill g o to a staggering 22 million inhabitants. The resulting sprawl threatens fertile agricultural lands and fresh water will have to be imported to satisfy the growing demand. Instead, by organising natural, agricultural and urban zones around a water basin, a biological cycle is eated usi g the la ds ape s atu al slope. Co pa t de elop e ts a e lo ated o the highest points, from which treated wastewater flows down to become irrigation water for agriculture, before it is returned to the natural water bodies. Rather than competing over water, cities provide farms with nutrient-rich water, while farms act as a buffer for the water reservoirs. This way, a growing population means more water for agriculture, creating a win-win scenario.

Figure 69: symbiosis between urban, agricultural and natural zones create a biocycle 112

4.5.2 VEGETATION As our cities keep growing, green spaces are diminishing. Especially the sprawling fringes of the city are expanding. This sprawl creates an impervious layer of roads and houses covering the countryside, that t aps heat a d stops ate f o seepi g i to the g ou d. This is t o l jeopa dizi g ou atu al capital, but the farms that feed our cities as well. Suburbs are putting increasing pressure on real estate prices, pressuring farmers to sell their land. Inside the city perimeter, green spaces are also disappearing. Public parks are seen as a financial burden, their maintenance abandoned as soon as budgets are cut. Similarly, private gardens are dwindling. In cities like London, 25% of the urban green (a considerable amount) is found in residential gardens113. Yet, increasing housing prices are encouraging the subdivision and infill of city blocks. Increasing density can still be good for cities, but only if green space is preserved. Our growing hunger for space has decimated our green urban environment. Satellite imagery shows that between 1985 and 2010, green space has shrunk in cities across the world114. Beijing lost 79% of, Brussels 64%, Seoul 69% and Los Angeles 44%.

Image source: Maki g Cit â&#x20AC;&#x201D;Atelier Istanbul - A hite tu e Wo k oo B ussels . Ba kha , I t odu i g T ee o o i s . 114 Baga a d Ya agata, La d-Cover Change Analysis in 50 Global Cities by Using a Combination of Landsat Data a d A al sis of G id Cells .

112

113

Figure 70: effects of imperviousness on runoff and infiltration115

This loss comes at a time when green space is more important than ever before. Climate change is resulting in hotter summers, more frequent and intense rai s a d isi g i e a d sea le els. As e e see at the egi i g of this hapte , ities a e o e p o e to te pe atu e ha ges, due to the heat isla d effe t. Ofte uilt ea flood plai s a d oastal a eas, ities suffe o e f o flash floods . Hamburg determined the damages of an extreme rain event on the 6 June 2011 cost between 27,3 and 46,1 million Euro116. Vegetation and natural ground cover are probably our best chance at mitigating climate change, if not our most cost-effective. They can moderate temperature, rainfall and groundwater reserves. The only problem that even though everyone likes and needs green space, it is often perceived as a cost. It actually turns out urban green is a good investment. The new Venlo City Hall (Netherlands) completed in 2015 integrates four major circularity elements: renewable energy, building as material bank, enhanced indoor and outdoor air quality and creating water loops. Next to the design and construction achievements, a concrete business case has also been de eloped: a additio al i est e t of € . M i sustai a ilit is e pe ted to esult i € . M savings in e.g. energy and water over 40 years. Positive cash flow was already achieved after one year. Further savings could be accounted once the relation between better indoor air quality and reduced sick-leave rate is proven. As de sit i eases it is e essa to e plo e g ee desig i o e eati e a s. A uildi g s oof and façade for example, can be an ideal surface for vegetation. The Venlo it hall s eyecatching green facade produces clean air for the occupants and its surroundings. Using natural ventilation, the purified air flows through the building, increasing employee productivity. The patio works as a helophyte filter, that purifies rainwater and wastewater from washbasins and toilets, combats heat stress increases biodiversity.

A old J a d Gi o s, I pe ious Su fa e Co e age . Grünig et al., Guta hte zu de öko o is he Folge des Kli a a dels u d Koste de A passu g fü Ha u g | E ologi I stitute .

115 116

Figure 71: the Venlo city hall presents a lot of green on a small surface117

A green roof has an increased lifespan of 40 years, instead of a t aditio al oof s ea s. The e a e also the reduced heating costs and storm water taxes. Conversely, a rooftop farm synergizes well with the building below, capturing rainwater and requiring 50% less energy than a ground-based greenhouse would, thanks to residual building heat118. The following total private costs and savings can be distinguished: 5- ea ost of $ , a d ea sa i g of $ , . This does t i lude 119 the increased value of reduced noise levels . The public value of a green roof includes smaller storm water infrastructure, carbon reduction, improved air quality, heat island reduction and habitat improvement. These effects combine in a 5year savings of $101,660 and 40-year savings of $191,421. Public green such as parks and street trees offer similar economic incentive by lowering the demand for energy and storm water infrastructure. There are additional benefits, such as increased property value, tourism and biodiversity120. Including social and health impacts would expand the economic impacts even further, as green environments reduce obesity and depression rates121. Peri-urban and urban farming can have a significant impact in sustainable food production, both in negative and positive ways. We will discuss this further below. Here we will discuss their economic benefits. They can produce significant amounts of vegetables and are economically viable, as sales margins in urban markets generate bigger profits than in rural areas. Considering public value, urban agriculture provides many benefits similar to green roofs and parks, ut o top of that the o t i ute to a it s ta e e ue.

Fl e a out C adle to C adle I spi ed Cit Hall Ve lo | C C-Ce t e . Elle Ma A thu Fou datio , High Yields, High a o e the Cit . 119 Case Studies Analyzing the Economic Benefits of Low Impact Development and Green Infrastructure P og a s . 120 M Kie, O e o i g the Ba ie s to U a G ee Spa e . 121 Nesle , A ess to Natu e Redu es Dep essio a d O esit , Fi ds Eu opea Stud . 117

118

As e e see ea lie , so e pla ts a treat contaminated air, water and soil by stimulating the growth of microorganisms that degrade the target pollutants. This process, also called bioremediation, is less expensive and more sustainable than other remediation alternatives122. Summarized, urban green can lead to: • • • • • • •

More resilience to climate change (floods, draughts) Healthy population (decreased pollution and obesity) Happier population (social interaction, decreased stress) A more liveable climate (urban heat island, noise pollution) Increased biodiversity Lower infrastructure expenses (storm water and energy) Better reputation and better economy

4.5.3 FOOD In the paragraph above, we hinted that urban agriculture can have very diverse effects depending on its context. Whatever the case, urban farms cover many urban needs beyond producing food, among which education and social inclusion, especially in community gardens. In areas that are prone to natural disasters, it is food security that gives it a unique appeal. Following the large storms such as Hu i a e Sa d a d lizza ds, Gotha G ee s, the o ld s la gest ooftop soil fa i Ne Yo k City, was still able to supply locally produced vegetables, while other supply chains had broken down. U a ag i ultu e s ost a itious goal ho e e , ould e the lo alizatio of food p odu tio . Cultivating roofs that are currently unused would reduce the environmental impact of food consumption by minimizing food miles. However, numerous LCA have shown that the emissions associated with transporting and storing food are minimal compared to those associated with producing food. agriculture 13 0%

processing 17

10%

20%

packaging 5

30%

transport

retail

15 40%

household

28 50%

60%

70%

out-of-home 18

80%

90%

100%

Figure 72: distribution of energy use in the U.S. food system (2002)123

Similar to traditional agriculture, the environmental impact of urban farms depends more on the cultivation methods (use of energy, fertilizers, etc.). Vertical farming for example, is a circular farming method suited for urban areas. Fish farming is combined with the cultivation of vegetables in a self-maintaining system called aquaponics. It usually involves growing plants in multi-storey warehouses without soil. Fish produce nutrient-rich water that is filtered by the plants and then recirculated. New technologies have enabled the monitoring and control of internal conditions like temperature, salinity and humidity.

122 123

G ee Re ediatio Best Ma age e t P a ti es: Sites ith Leaki g U de g ou d Sto age Ta k S ste s . Pelletier et al., E e g I te sit of Ag i ultu e a d Food S ste s .

Figure 73:aquaponic system diagram124

The method has a number of advantages125: • • • • • • •

90-95% reduction in water demand Fertiliser use reduced by 70% No use of herbicides or pesticides Reduced food waste Optimal use of space Ability to grow throughout the year Shorter supply chain

There are some clear disadvantages however. First of all, can we afford to use valuable city real estate as farming grounds? A more pressing question is the energy intensity of vertical farming. A vertical farm not only needs heating, but also lighting, ventilation and 24/7 water circulation. Based on the daily light intake of lettuce, the current efficacy of lighting, and the lowest CO2 cost of power in the region, professor Michael W. Hamm calculated the energy impact of a kg of lettuce for the state of New York126.

A uapo i s | Po tfolio a Els E gel . Egerton-Read, Wh La ge S ale I doo Fa s Will Be C u ial to Feed Ou Fast G o i g Cities . 126 FCRN Blogs : Mi hael ha | Food Cli ate Resea h Net o k FCRN .

124 125

PRODUCTION SYSTEM

KG CO2/KG LETTUCE

Import average of 2900 miles (ca. 4700km)

0.70 (transport only)

100% Artificial lighting (High Pressure Sodium)

3.95 (lighting only)

70% Sun/ 30% Artificial Light with CO2 addition

0.71 (lighting only)

As e e see , ag i ultu e s thi st fo e ergy, water and nutrients are intimately related to the city. Urban farming has a lot of potential regarding synergies that might improve this relationship. Still, we should scrutinise promising stories like that of vertical farming or we might find ourselves worse off than before.

4.6 ENERGY Buildings today consume 40% of all generated energy, more than either industry or transportation (both around 30%). We can optimise this consumption by installing thicker thermal, but even a passive house still needs energy to keep the lights on and the ventilation running. Despite our efforts to reduce energy consumption, it remains the most import factor regarding environmental impact. As long as this energy is derived from fossil fuels, buildings will remain unsustainable. Suppose we switch over to renewable energy, how do we make sure our power is managed effectively and reliably? Photovoltaics seems to be making their way onto every rooftop, but is this a feasi le solutio ? It does t see so. Not o l does the production fail to match the demand under perfect conditions (peak production at noon, peak demand at 5pm.), solar irradiance is very irregular and changes throughout the seasons.

Figure 74: peak PV production versus peak load

We would eed e o ous sola pa els a d atte ies to ha e e ough e e g at all ti es, hi h is t possible since there are simply not enough resources to produce them all (see Figure 9Figure 9)Figure 9. Other renewables suffer from the same limitations, either too irregular or not enough to satisfy our needs. If we really want renewable energy to work on a wider scale, we will need to combine different sources in a network with enough storage. 69

While we can make the distinction between heat and electricity as a medium for energy, they have similar requirements for their network to be based on renewable energy. Sometimes, one medium complements the other. 4.6.1 DISTRIBUTION One way to equalize electricity suppl a d de a d, is ela i g a su plus to he e it s eeded. While ou a e t usi g the po e ge e ated ou sola pa els, so eo e else a ake use of it. Energy peaks are stabilized, which means grid overload is avoided. A smart meter keeps track of your total consumption and production. Now combine this with all the storage capacity that is not being used at that moment. An electric vehicle on the parking lot or your laptop that is charging. maybe even a smart washing machine waiting for some unused wind power to start its programme. We call the combination of these properties (hybrid sources, distributed production, dynamic storage and load anticipation) a smart grid or microgrid. But heat is probably the best sink for electrical energy there is. Your smart meter notices a surplus on the electrical grid, so it tells the heating (or cooling) system to start working, converting electrical energy into thermal energy. This is where the synergy between different energy systems shines. Especially since heating/cooling takes the largest share of our daily energy consumption.

Figure 75: collective generation and storage in a smart micro grid127

127

Image source: Ci ulai e oo

ijk i Rotte da

i de ijk Heijplaat .

This heat could be generated at home, locally converting fuel or electricity in a boiler or heat pump. Alternatively, heat (and electricity) can be generated and distributed in a centralised network, ideally at low temperatures. This system is called district heating. Its principles are similar to those of the electrical smart grid. Heating surplus created in industrial plants and offices can be used to heat homes or can be stored underground or in collective buffers. Hybrid heat and electricity networks combine the benefits of centralized and distributed generation and storage, to be more resilient and efficient. The succes of these networks depends on how well different parties can cooperate. Long term regulations protecting system integrity are key to an effe ti e olla o atio . This does t e essa il ea a e t al autho it eeds to control the grid. In New York, a smart grid controlled by a blockchain fascilitates the trade of renewable energy between consumers, without the interference of a central energy company128. There are fewer infrastructural losses and both energy and money return to the community.

Figure 76: district heating network129

4.6.2 GENERATION - STORAGE What kind of sources and buffers can tap into these decentralized grids? As most readers are probably already familiar with the workings of photovoltaics, solar collectors and wind turbines, these ethods of e e g ge e atio o t e dis ussed. The ight pla a i dispe sa le ole i a decentralised grid, however, these technologies alone cannot support a microgrid. This is why we are going to focus on less known technologies. CHP (combined heat and power) or cogeneration units use fuels like a traditional generator to produce electricity, but also recover the heat that remains after combustion. This cogeneration of heat and electricity is more efficient than if they would happen separately.

128 129

Blo k hai -Based Microgrid Gi es Po e to Co su e s i Ne Yo k . Va de Veke , Ku o , a d Va de Boss he, Hoe gaa e o s e a

e i

Figure 77: seperate heat and electricity generation versus cogeneration130

To provide renewable energy, these CHPs would need to run on synthetic fuels based on biogas or hydrogen. As we e see ea lie , iogas de i ed f o solid o ga i aste a d se age t eat e t plants could yield considerable amounts of energy. Theoretically, wastewater has 14 times as much embedded energy as is required to treat it. In practice a treatment plan can produce 10% more energy than it needs to be self-sufficient. An analysis of sewage treatment plants in the US found that olle ti el , the ould eet % of the atio s ele t i it de a d. Fuel cells can be used to convert electrical energy into chemical energy (hydrogen for example) and vice versa. While a lot more energy dense than conventional batteries, the conversion process remains relatively inefficient due to heat losses. Combined with a heat recovery system however, fuel cells are an ideal storage e ha is fo oth the al a d ele t i al e e g i hat s alled a micro-CHP. These cogeneration units are more compact than their combustion driven counterparts and are finding their way into many Asian households, especially in Japan. Today, electronics, photovoltaics, storage batteries, electric vehicles and other end-use devices all run on DC power. While the demand for AC power remains stable, the demand for DC increases exponentially as traditional systems are being replaced by more efficient DC powered ventilation and lighting systems. Yet, while our homes contain more DC powered appliances every year, our energy supply runs exclusively on AC. The conversion of AC to DC is costly and inefficient, delaying a transition to renewables. Directly usi g DC po e f o photo oltai s to LED ould t o l e safe , ut ould ut ele t i it use 20%131. Improvements of the total efficiency would be roughly 1/3rd compared to the losses that come from converting power from DC to AC back to DC132. Feeding power through USB or ethernet cables would not only limit the number of connections required, but connect your devices to the internet.

No the Utilities | Co i ed Heat a d Po e . Glasgo, Aze edo, a d He d i kso , How Much Electricity Can We Save by Using Direct Current Circuits in Ho es? 132 Ti e to Rethi k the Use of DC Po e fo the E e g -Smart Home? | Greentech Media . 130 131

In building design, thermal mass is a property which enables a building to store heat, a passive atte , p o idi g i e tia against temperature fluctuations. To be effective, thermal mass must be integrated with appropriate passive design techniques, such as glazing, shading, insulation and ventilation. This heat can originate from either an internal load (people, appliances or heating s ste , o sola e e g . I li ates ith la ge te pe atu e a ges, the al ass allo s a uildi g s interior temperature to remain stable as solar irradiance changes throughout the day. In more temperate climates the advantage comes from a buildi g s a ilit to itigate a ia le i te al load. When there is an excess of heat on the grid for example, a building can store this cheaper energy for later, using its thermal mass.

Figure 78: the effect of thermal mass

SUMMER

WINTER

Figure 79: using passive design to mitigate temperature133

Excess heat can also be stored for longer periods of time using STES seasonal thermal energy storage. A GSHP or ground source heat pump uses the earth as a heat source (in the winter) or a heat sink (in the summer). This design takes advantage of the moderate temperatures in the ground to boost efficiency and reduce the costs an impact of heating and cooling systems; Heat captured and stored in thermal banks in the summer can be retrieved efficiently in the winter. Heat storage efficiency increases with scale, so this advantage is most significant in district heating systems.

133

Image source: You Ho e .

COOLING DEMAND

HEATING DEMAND

Figure 80: seasonal thermal energy storage

4.7 PEOPLE From an urban perspective, one could say people are just another resource. The same way water o es th ough i e s a d pipes, people flo et ee uildi gs. We use i e s alled st eets a d underground tunnels are so eti es lite all alled the tu e . It ight see dehu a izi g, ut if anything, it points out how careless we are with regards to other resources. This perspective allows us to better understand the city as a network. Food, data, energy, but also people move from one building to another using different circuits. In a city, every other resource revolves around us, ut the people et o k spe ifi all o sists of housi g that sto es us a d o ilit that t a spo ts us. 4.7.1 HOUSING The trend for housing is simple: more. There are 3 million people moving to cities every week134. Cities are either going up or going out. Even though compact development has been shown to be more sustainable compared with sprawl, the average city is spreading out. According to the World Bank the global urban population has been growing at 1.7% per year. Yet the density (number of housing units or inhabitants on a given area) has fallen by 2.2% year135. This trend is not only de i ati g ou atu al e i o e t, ut it s ad e sel affe ti g ou o li ea ilit . Take Flanders for example. Even though our population is completely urbanised, barely 30% lives in ities, o pa ed to Eu ope s a e age of %136. This low-density development has created a fragmented landscape, making us European champions in the following categories: • highest percentage of impervious surface area • most congestion hours per commuter • most utilities and roads in km

Coll e , Th ee Millio People Mo e to Cities E e Week . Ro e ts, Cha ges i U a De sit . 136 Va B oe k, Spatial pla i g e o d the g ee solutio s . 134 135

Figure 81: Flanders' sprawling urban zones137

Low density is also detrimental to the economy: it decreases business opportunities, effectiveness of public services and means a higher energy intensity (energy consumption per unit of GDP). That is why most cities are working on strategies to increase urban density. This is a difficult process however, as urban planning often discourages compact development, and people see dense living as synonymous with modernist towers. When buildings become so massive that they create skyscraper canyons, street life disappears and interaction is limited, creating the same isolation that is more commonly associated with sprawl.

parks & recreation solid waste fire department governance police transportation libraries school bussing culture / economy roads transfers to provinces sidewalks and curbs storm and wastewater water TOTAL

SUBURBAN 129 185 406 297 360 171 72 87 36 280 435 194 613 197 3462

URBAN 69 185 177 158 192 91 38 13 19 26 232 27 147 42 1416

Figure 82: city's annual cost per household in Halifax, Canada138

Image source: Beelde - Co eptstudio sâ&#x20AC;&#x201D;Beleidsplan Ruimte Vlaanderen - Architecture Workroom B ussels . 138 Sustai a le P ospe it | .

137

But de sit does t e essa il i pl high-rise, as similar densities can be attained using different building typologies. Quite the contrary. Small scale, green, low to medium-rise typologies often manage to house more people per km² than urban areas with taller buildings. Some examples of neighbourhoods desired for their charming character, with building heights of 5-7 layers: • • • •

Chelsea, London139: Södermalm, Stockholm140: Montmartre, Paris141: Eixample, Barcelona142:

13,000 inhabitants/km² 22,000 inhabitants/km² 31,000 inhabitants/km² 36,000 inhabitants/km²

Brussels, often quoted as being too crowded, reaches a peak de sit of o l 20,900 inhabitants/km²143.

Figure 83: density can be achieved in different ways144

4.7.2 MOBILITY What do these neighbourhoods have in common that makes them so compact? The reason is not simply their high land values. If so, why would our cities decrease in density, when land values are rising? The reason is mobility.

List of E glish Dist i ts Populatio De sit . Mappi g Populatio De sit A oss the Glo e . 141 th A o disse e t of Pa is . 142 Ei a ple . 143 Mappi g Populatio De sit A oss the Glo e . 144 Image source: Force, Towards an Urban Renaissance. 139 140

These neighbourhoods are all located near the historical centre of cities and predate the widespread use of cars (or elevator). Turns out transportation and sprawl are two sides of the same coin. Cars not only enable us to live further apart, the associated car infrastructure takes up half of our precious city surface. Parking spa es, ide oads a d high a s all o t i ute to the a s footp i t. As a result, we are living so dispersed, public transportation is no longer a viable alternative, making us even more reliant on private transportation.

Figures for 1990 Population Built-up area Length of metro lines % of population within 600m from metro station % of trips using metro Tonnes of CO2 / person

Atlanta 2,5 million 4.280 kmÂ˛ 74 km 4% 4,5% 7,5

Barcelona 2,8 million 162 kmÂ˛ 99 km 60% 30% 0,7

Figure 84: compact development can reduce transport emissions145

The feedback loop between density and mobility is most apparent when we consider energy consumption. Private transportation requires more fuel and low-density housing loses more heat, leading to a drastic increase in CO2 emissions.

145

Be taud a d Ri ha dso , T a sit a d De sit : Atla ta, the U ited States a d Weste

Eu ope .

The solution might seem simple: increase population density. But there are several other parameters to consider. First of all, proximity of functions. Dense or not, a monofunctional urban fabric necessitates transportation in order to get places. Second, people are more mobile today than before the car. We cannot expect people to give up the freedom to go wherever they want to. Third, even if urban densification reduces per capita car use, doubling population density will not halve the frequency of car use. it will also increase concentrations of motor traffic, which locally aggravates the negative externalities such as congestion and air pollution146. Except for densification, we have to take other measures to reduce the impact of transportation. This includes both private and public transportation. Currently, transportation by car is probably our least efficient use of resources. Not only do they require a lot of space, cars spend most of their time standing still. In Europe, a car spends 1% of its time in traffic, 2% of the time looking for parking, 5 % actually driving, and 92% of the time parked. The e s o e. The a e age a has seats ut o es o l , people, hi h ea s the dead eight ratio (how much useful mass are we moving) is 1:21. Not even considering deaths caused by air pollution, traffic accidents cause 30.000 fatal injuries and 4 times as many permanently disabling injuries. Over 95% of these are caused by human error. (All figures for Europe). Even if we replaced every car with an electric vehicle, all these problems remain unsolved. There are several other improvements we can consider to improve their efficiency. Car sharing for example, increases the time a car is used to 4-5 hours a day, but autonomous cars on demand can improve this further, up to 9 hours a day. All in all, we would only need 10-20% of our current car fleet to meet mobility demands. Last but not least, autonomous cars would cut accidents by 90%.

Figure 85:mobility on demand combines complimentary technologies147

Autonomous cars drive more efficiently and can convoy with other autonomous vehicles, accelerating at the same time, keeping equal distance to other vehicles. This decreases congestion by 50% and improves energy efficiency. When more individuals use navigation systems, this can lead to la ge u e s of ehi les si ulta eousl hoosi g the fastest alte ati e oute he a oto a is 146 147

Melia, Pa khu st, a d Ba to , The Pa ado of I te sifi atio . Image source: Growth Within: A Circular Economy Vision for a Competitive Europe, 60.

congested. Paradoxically this can slow down everyone. Using real-time adaptation, autonomous cars communicate and collectively change their route to balance traffic. Using inductive charging, an electrical vehicle can be charged wireless. This might seem like a gadget, but this technology could further enhance the possibilities of on demand mobility. Once passengers arrive at their destination, a self-driving vehicle in need of recharging could drive towards the nearest statio to e ha ge its atte , all itself. The sa e a ou do t ha e to pa k o efuel a ta i afte the ride, a completely autonomous car takes care of itself too. The combination of these technologies could drastically improve private transport efficiency. Simultaneously, they could eliminate the need for short distance public transportation as well. Instead of driving a single passenger at a time, on-demand vehicles could overlap the routes of multiple passengers, picking them up and dropping them off at their desired destinations. But what about mass transit over longer distances? Depending on several factors (compatibility, regulations, costs,) on-demand vehicles might not be the best way to take us from one city to another, let alone across the country. Whatever the case may be, other modes of transportation are here to stay for the foreseeable future. To be able to compete with individual transportation, rapid mass transportation has to be more o e ie t tha toda s u e so e pu li t a spo tatio s ste s. As e e see ea lie , ou sprawling cities are not compatible with efficient mass transit. Either because they cannot reach enough people (Atlanta), or because they would require an extensive network that is too costly to support (Flanders). A mass transportation network works best with fewer and more intense connections (see Figure 55). Rather than having bus stops within 500 meters of every home, a multimodal transportation hub in the city centre will be used more frequently and requires less maintenance. From such a station, diffe e t odes of t a spo tatio ould deli e hat is k o as the last ile solutio . These transportation modes could range from the on-demand car service, to bike sharing, to simply walking.

Figure 86: one-mile walk in a compact neighbourhood or a sprawling suburb148

148

Image source: Map of a Co pa t Co

u it .

Within walking distance to such a station, the development of high-density mixed land use would create a positive feedback loop. High density development facilitates the efficient exploitation of the transportation network, which in turn increases land value and allows for more qualitative mobility for everyone. This synergy between transit and development is called transit-oriented development or TOD. The combination of this strategy with that of a community land trust (CLT) could further enhance this synergy. Ownership over both land and network would mean that increased land value created by the investment in public infrastructure would return to the community.

Figure 87:TOD or compact nodes linked by mass transit

The acclaimed Finger Plan is an urban plan for the development of the Copenhagen metropolitan area and is one of the earliest attempts of a TOD planning. The design is based on five corridors along su u a a eas o e ted ail li es that go di e tl to Cope hage s e t al usi ess dist i t. Around the stations are high-density areas with mixed land use, while between the fingers, green wedges provide land for agriculture and recreational purposes. Wherever a good connection to public transport exists, pedestrian areas and bicycle facilities reduced car dependency.

Figure 88: Copehagen's transit-oriented Finger Plan149

The circular scenario could reduce urban sprawl up to 30,000 square kilometres by 2050, compared with the current development scenario. CO2 emissions could fall as much as 85 percent below 2012 levels, or 50 percent compared with the current development scenario. 149

The Fi ge Pla at

4.8 CONCLUSION In this chapter we lifted circularity from the level of the building to that of the city. By looking beyond construction materials, we analysed several key resource flows and their interaction with each other and the environment. Fi st, e e see the i pa t of the i easi g urbanisation worldwide and how this immense growth puts cities under a lot of pressure. Buildings are highly dependent on external infrastructure and limiting this could be beneficial, both to the occupant and the external infrastructure. Providing their own resources, buildings can be connected in a collaborative network that is selfsustaining, but for that to become reality, the management of information is required. The digital revolution provides us with this data and is one of two key ingredients to a sustainable city. Technologies like asset tagging, geo-spatial information, big data management and connectivity all contribute to the second key ingredient, a circular economy. Finally, we explored the different resource networks in a city and how these can become regenerative, rather than a burden. Space is ultimately the only limited resource. The way it is currently organised and owned restricts its usability. By employing the same adaptability used in our uildi g s desig a d e plo i g diffe e t property models, land value can be increased and divided more easily. The urban biocyle encompasses all organic flows through our cities. Waste, water and food are closely related and can regenerate each other on multiple scales, from the building level to the territorial scale. Urban green, both public and private, can efficiently help us mitigate the effects of climate change on our cities. Even though it is usually considered an unnecessary cost, we have seen they greatly increase the value of our urban environment. Currently, agricultural and urban development are competing for resources. Different (peri-)urban farming models can turn this food cycle into a symbiotic relationship. When thinking of building sustainability, the issue still largely revolves around energy (both electricity and heating) and for good reason. Facing the dawn of renewable energy, we have to address several questions. First of all, how are we going to generate and store enough energy to satisfy our demand? Climate responsive design combined with alternative energy technologies might complement the current solar and wind driven systems. Secondly, what is the most efficient way to distribute this energy? Decentralized smart grids and distributed district heating could optimise our energy use, especially when integrated with one another. Our own homes would play a significant role in such a system. Housing and transportation are the two factors that have a deciding impact on urban density. Higher densities tend to be more sustainable, yet our cities are sprawling more than ever. People fear living in skyscraper canyons, but a qualitative density can be attained, even in green, small scale neighbourhoods. A combination of on-demand vehicles and transit-oriented development can decrease our dependency on private transportation, significantly reducing sprawl.

Figure 89: power, vegetation, transportation, buildings, water, space and waste are all part of the urban metabolism

For our cities to become more sustainable, urban planning will have to define regulations that go beyond aesthetics and ad hoc problem solving. Rather than a machine, a city should be understood as a metabolism. Instead of fixing problems as they emerge, a city should grow feedback loops that reinforce each other. This holistic approach is more resilient to changing conditions, combining effectiveness with efficiency.

5 SUMMARY The current sustainability paradigm focuses all effort on optimising the current system, rather than transitioning towards a new one. As a result, the housing and construction sectors are detrimental to society, economy and environment. This dissertation tries to find out how circular building can offer an alternative by exploring concepts on multiple levels, ranging from building element to the scale of the city. It starts with a chapter on the circular economy, since this forms the prerequisite framework to u de sta d i ula uildi g. The hapte s o uildi gs as ate ial a ks a d u a eta olis can be understood as the consequences of circular building.

Figure 5: chapter structure

First, we explored the circular economy and its principles. By shifting towards a regenerate-reusereduce model, we can close the technical and biological material loops. This creates value as opposed to the linear take-make-dispose model, by using performance to link economy with sustainability. We e see ultiple usi ess odels that appl these p i iples that are suited for the housing and construction sector and discussed how governments and citizens can find a way to manage these disruptions. We continued by having a look at the technological developments that made circular building possible. In the third chapter we explored how a building and its elements can be designed, constructed and maintained in a circular fashion, by taking lessons from more industrialised and digitalised sectors. A circular building is a temporary collection of components that are identifiable. The goal of a circular building is to regenerate and increase its value. We can achieve this by designing it in an adaptable way and storing its information in material passports. Both of these desig st ategies o i ed akes the uildi g s elements reusable and gives us what is known as a Building As Material Bank or BAMB. Building adaptability is the result of scenario development, element compatibility and reversible connections, while material passports are used to store element value, facilitate element exchange and monitor resource consumption. The final chapter discusses how a circular building functioning in a larger network like a city can contribute to the sustainability of the overall system. Here we look beyond building components, also addressing other resources that are parts of our built environment like water, electricity, waste and land. Rather than a machine, a city should be understood as a metabolism. Instead of fixing problems as they emerge, a city should grow feedback loops that reinforce each other. This holistic 83

approach is more resilient to the changing conditions our cities are facing. We e see the i pa t of the increasing urbanisation worldwide and how this immense growth puts cities under a lot of pressure. Providing their own resources, buildings can be connected in a collaborative network that is selfsustaining, but for that to become reality, the management of information is required. The digital revolution provides us with this data and is one of two key ingredients to a sustainable city. Technologies like asset tagging, geo-spatial information, big data management and connectivity all contribute to the second key ingredient, a circular economy. Finally, we explored these different resource networks in a city and how these can regenerate each other, rather than being a burden. The future role of architects and urban planners needs to be redefined. If buildings are conceived as adaptable configurations of standard building components made of building kits, designing and constructing buildings can become accessible to more stakeholders, not only architects. For our cities to become more sustainable, urban planning will have to define regulations that go beyond aesthetics and ad hoc problem solving. If the construction and real estate sectors want to keep up with these disruptive technologies, they will have to evolve.

5.1 CIRCULAR CRITERIA As a conclusion to this dissertation, the important circular concepts and techniques are summarized in a list of criteria for a circular built environment, both on a building level and on an urban level. These are then tested on a case that is under development at the time of writing. For the unabbreviated names of criteria, see list of abbreviations. I.

Design and construction A.

Materials: choose materials that are sustainable 1.

Durable: can handle several lifetimes

Healthy: nontoxic to ensure healthy environment

Pure: can be separated more easily

Low impact: consider environmental effects according to LCA

Circulate: reuse, repair or recycle elements, buildings and infrastructure

Connections: reversible for repeated disassembly 1.

Accessible: have few connections with sufficient tolerance

Standardised: simple connections decrease construction time

Mechanical: dry joints allow deconstruction without damaging materials

Chemical: if necessary use lime mortar or easily dissolvable binders

IFD: build according to open industrialised systems 1.

Modular: elements are designed according to a set of rules

Standardised: elements are interchangeable, also in other buildings

Prefabricated: construction is quicker and consistent 84

4. D.

II.

Chunked: complex compositions should be grouped in components

Design for change: keep the entire lifetime of the building or neighbourhood in mind 1.

Layered: separate elements by function so they remain independent

Optimised: reduce structure, techniques and circulation

Adaptable: make the design transformable, moveable or multi-purpose

Anticipating: develop probable scenarios to make informed decisions

Redundant: overdimension and plan for expansion

Diverse: mix functions and types to create resilience

End-of-life: plan for reverse construction instead of demolishing

Flowing resources A.

Energy: heat and electricity 1.

Save: implement passive design and efficient technologies a)

Low temperature radiant heating

Drain water heat recovery

High performance glazing and insulation

Solar gains: controlled by appropriate shading and orientation

Low air infiltration

Natural ventilation: cross- ventilation, heat stacking, night flushing

Demand-controlled mechanical ventilation with heat recovery

Natural daylight: maximise room penetration

Lighting: efficient, dimmable and automatic

Generate: renewable production for self-sufficiency a)

Solar collector: delivers high temperature water

Photovoltaic: convenient individual electricity production

Wind turbine: produce most during winter, complementing solar

(m-)CHP: combined electricity and heating

Heat pump: efficient electricity to heat conversion

Store: balance consumption and production a)

STES: balance heating and cooling demand across seasons

Fuel cell: dense storage for electrical energy. 85

Biogas/biofuel: waste to energy

Battery: dedicated or shared with an EV

thermal mass: buffering heat to stabilize temperatures

Distribute: decentralized grids combine efficiency and effectiveness a)

Mixed ac/dc circuits: minimize conversion losses

Smart/micro grid: balance electricity demand and supply

District heating: recovering waste heat at low temperatures

Waste: all resource that conventionally leave the system can be recirculated 1.

Rainwater collection: reduces drinking water consumption

Waste stream separation: both fluids and solids recycled

(An)aerobic digestion: biogas/biofuel from organic waste

Garbage disposal unit: feed organics into black water stream

Urine diverting/ vacuum toilets: save water and separate waste

Black water: nutrient recovery for fertilization

Grey water: recycling within and buildings and farms

Mobility: combining housing and transportation 1.

Transit oriented development: complementary housing and transportation a)

Zoning: qualitative density to sustain infrastructure

Transportation hub: creating multimodal systems

High speed mass-transit: few and far between for fast connections

Walkable/bikeable neighbourhood: decrease motorized traffic

Autonomous cars: complementary to public transport as a last mile solution a)

Mobility on-demand: increases accessibility

Shared vehicles: limit traffic

Wireless charging: completely independent vehicles

No street parking: frees up public space

Real-time adaptation: alleviates congestion

Urban green: public and private vegetation to protect the city 1.

Buffers rainwater: mitigate heat island effect and flooding

Bioremediation: decontamination of soil, water and air 86

III.

(Peri-)urban farming: synergize urban and agricultural needs

Aquaponics: symbiotic species decrease water and fertilizer consumption

Nudging: influence occupant 1.

Monitoring: inform and incentivize occupants to lower consumption

Behavioural design: facilitate sustainable, healthy and social behaviour

Value and partnership A.

Material passport: retaining product information 1.

Documentation: to ensure quality and value of materials a)

All inclusive: all relevant information from material to building level

Accessible: for relevant partners during whole process

Responsibility: ownership should be clear

Identification: physically and digitally linked to database

Maintenance: ensures value of materials remain a)

Physical guidelines: how retain initial quality

Digital passport: update when changes are made

Restoration: how can materials be reused after disassembly

Monitoring: active and passive to evaluate condition

Business models: running the circular economy 1.

Physical: new jobs and facilities to handle and manage resources a)

Material condition inspection

Deconstruction

Material stock management

Product refurbishment

Financing: alternative value propositions a)

3rd party financing: facilitate service contracts

Smart contracting: decentralized authority

Cap and trade budgeting: incentivize sustainable behaviour

Alternative currencies: time banking, crypto, city currency

3. Consultants: bring parties together collaboration agreement between interdisciplinary parties, sharing knowledge

New models: alternatives to conventional consumption a)

Access over ownership: service instead of product

Leasing: user returns performance-based product after period

Take back: companies facilitate end of life of products

Reverse logistics: handling products returned to the material stock

Property: alternatives to the rent/buy models 1.

DBFMO: building as a complete service package, from design to operation

Cooperative: combine freedom of renting with agency of buying

CLT: separating land from construction increases community value

CPC: occupants act as developers and are involved in process

TDR: creating sustainable density without inflating housing supply

Process 1.

BIM: communicate design and information with all involved parties

VDC: optimise construction process and coordination

LBC: early involvement of all stakeholders allows for entire lifecycle design

DIY: buildings satisfy occupant demands thanks to mass customization

5.2 CASE BUIKSLOTERHAM We will start by going over the circular elements this case features and then discuss what criteria it lacks to be fully circular. Buiksloterham, the previously industrial area located at the northern fringes of Amsterdam is being redeveloped by a combination of public and private stakeholders. Its ambitions are to become living lab for the circular built environment. In march 2014, 20 organisations signed the Manifesto Circular Buiksloterham, engaging themselves to make Buiksloterham an example of circular development. The development is ongoing and will run until 2030. For now, the area still comprises some abandoned and polluted industrial sites, but the neighbourhood will ultimately provide 3500 housing units and 200.000mÂ˛ of working space. The masterplan consists of four parts with their own character, target group and circular concepts. The ambitions cover several themes: energy, mobility, urban green, material, water and community. Not all ambitions are as high, with some being musthaves and others nice-to-have.

Figure 90: Buiksloterham's ambitions150

De Ceuvel, has already been completed in 2015 and caters to artists and alternative households, also called place makers. The circular elements of the system at the Ceuvel are, amongst others: • • • • • • • • • • • 150

individual helophyte filters that purify grey water from the kitchens individual dry-compost toilet the café has urinals with separate urine collection a greenhouse equipped with aquaponics systems reuse of old boats and construction materials temporary infrastructure: no foundations, no underground infrastructure temporary utilisation of contaminated soil the organic waste produced at the Ceuvel will be used to produce biogas and digestate 70-80% of the nutrients from the waste water are recovered. compost is used in the greenhouse for investigations into experimental food production. struvite recovered from the urine collection of the café is being looked into as fertilizer

Delva, Buiksloterham circulair.

Figure 91: de Ceuvel's biocyle151

Schoonschip is a CPC in which the future home owners coordinate the development through the Schoonschip Foundation. Works started in 2017 and should be completed in 2019. Its target audience are wealthy homeowners, also called birds of paradise. A highly involved community has been the driving force behind this ambitious project from the start. The broad performance standards have been integrally incorporated in the building envelope. As a result, inhabitants agree with the use of sustainable techniques from the outset; not just in relation to the eside e s e e g a d ate ial usage, ut also ega di g its usage of ate a d io ass. Amongst its circular technologies are • • • •

151

decentralised waste water processing in a biorefinery a smart DC net, low impact construction materials. pre-fab construction methods.

Delva.

Figure 92: Schoonschip is a floating community152

Self-construction Klaprozenweg is the largest plot in Buiksloterham that is entirely intended for individual self-constructors, also called colonizers. With this, self-construction is no longer limited to rustic and suburban neighbourhoods, but has become a serious player in inner city. The owner may construct two buildings per plot, and a large part must be used for economic activity. With this, the de sit of the a ea is si ila to A ste da s old it dist i ts. The layout is based on a simple grid with back-to-back subdivision with an access point in the middle. The building envelope foresees a large volume on the street side, a garden or low volume in the middle and a medium volume on the inner-street side. This makes a high density possible; resulting in an FSI of 2 to 3 on the plot. This results in an eclectic development. It is every household for itself without a great deal of exchange of materials, energy, etc. In addition, several of the inhabitants have chosen not to plug into the heating grid but will generate their own heat. Cityplot is aimed toward more urban residents, called developers, and is the largest of the four parts of the masterplan. Its preparation started in 2016 as a cooperative and is still under construction. Here, social rental housing can be found next to self-construction and owner-occupied apartments, living next to working, water next to land, high next to low, urban next to village-like. The layout in this area is adaptive, in order to respond to developments and changes that may occur in the future. Buildings can transform, and are, where possible, flexible in terms of surface area and function. The area is not completely built up at the same time, but consists of developments of different scales, while keeping space free for future functions.

152

S hoo s hip â&#x20AC;&#x201D; Spa ea d atte .

This neighbourhood consists of three plots with a depth of about 90 m, with a central public space. The public space is characterised by the ambition to make the area sheltered from the rain. By parking centrally, the neighbourhood is low on car traffic, allowing for its plot-based development. Each plot consists of border developments of 4-8 layers and an inner area with ground-bound residences and working buildings of 2-3 layers. The corners are accentuated by 6-9-layered construction. The density is urban with the e ti et s FSI ei g . . In terms of water, the ambitions are high: rainwater will be separated from the sewage system and the units of will be equipped with vacuum toilets that lead organic waste to a biodigester in the neighbourhood. The black water will be cleaned and recycled for biogas and fertilizers. In terms of energy, the focus is on PV panels, LED lighting and monitoring. The waste heat present in the grey water is also recovered and used to heat the units. The cooled grey water is collected in the existing sewerage. Furthermore, buildings are constructed energy-efficiently and roofs are used for solar panels and/or as green roofs.

Figure 93: City plot makes the most of its roof surfaces153

If we now evaluate this case according to the criteria p ese ted ea lie , e a tell Buikslote ha s ambitions as a circular development are indeed very high. It deals with the different circular perspectives (construction, design, resource flows, value and partnership) to at least some degree. Especially resource flows and partnership have been thoroughly explored. However, Buiksloterham is lacking in the circular construction department. Even though the plot layout is adaptable and the materials reused or low impact to some extent, on a building level the construction process remains conventional. There is no mention of reversible connections or modular elements. Not having the DIY neighbourhood Klaprozenweg be built from standardized parts for example, is a missed opportunity. The absence of material passports also prevents the implementation of performance-based service contracts that ensure the reuse of construction elements.

153

Ri aldi, Cit plot Buikslote ha

Studio i edots a d DELVA La ds ape A hite ts .

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