DETAIL Green English Edition May 2014

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∂Green 01/14 DETAIL Special Edition 66266 ISSN 1868-3843

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Magazine Something in the air: the spirit of activism in young architects Oliver Lowenstein

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Projects

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Publications, Events

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Background Passive House or Active House? Two competing building concepts Interviews with Wolfgang Feist and Manfred Hegger

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Sustainable architecture

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Office building in Agoura Hills ZGF Architects LLP, Los Angeles

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Conversion of a grain silo in Middelburg Rothuizen Architecten Stedenbouwkundigen, Middelburg

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School in Bad Urach ArGe KBSU, Pfullingen - Thomas Bamberg, Markus Haug, Eberhard Wurst

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Holiday house on Laesø island Tegnestuen Vandkunsten, Copenhagen

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Research and practice Internal insulation of external walls: design guidelines and system selection Daniel Zirkelbach, Hartwig Künzel

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Electrochromic glazing: properties and design guidelines John Mardaljevic, Ruth Kelly Waskett, Birgit Painter

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Products and materials

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Specialist information Sustainable design teams, methods and tools in international practice Emanuele Naboni

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Planning partners and manufacturers

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Editorial and publishing data/photo credits

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www.detail.de/english Publishers and editorial department: Institut für internationale Architektur-Dokumentation GmbH & Co. KG, Hackerbrücke 6, 80335 Munich, Germany, Editorial department: Christian Schittich (editor-in-chief), Jakob Schoof E-mail: redaktion@detail.de, telephone: +49 89 38 16 20-57; Advertising: e-mail: anzeigen@detail.de; telephone: +49 89 38 16 20-48; Distribution & subscriptions: e-mail: detailabo@vertriebsunion.de; telephone: +49 61 23 92 38-211 UK correspondent: Oliver Lowenstein Translations: Sharon Heidenreich, Lance Phipps, Feargal Doyle, Sean McLaughlin English copy-editing & proofreading: Anna Roos

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Content/Editorial

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Many architects are still puzzled by what exactly a ‘sustainable’ building is. Now the next buzzword is entering the architectural debate: namely, the ‘Active House’. In the past year the association, ‘AktivhausPlus e.V’ launched an initiative in Germany to promote the construction of plus-energy homes. The Active House Alliance is pursuing a similar goal on an international level. The underlying message is clear: an Active House is per definition the antithesis of a Passive House. An Active House should not only function in a climate neutral and environmentally friendly manner, but it should also offer its occupants the best possible internal thermal comfort and air quality.

Interestingly, these claims are almost identical to those that the proponents of the Passive House uphold for their own concept.

So what is really new about Active Houses? Are they simply old ideas dressed up as new ideas?

To find out the answers to these pertinent questions we spoke with two protagonists of energy efficient building: Manfred Hegger – co-founder of AktivhausPlus e.V. and long-time president of the German Sustainable Building Council (DGNB) – and Wolfgang Feist, founder of the Passive House Institute. Both interviews in this edition of DETAIL Green emphasise the differences between both positions, as well as their fundamental similarities. The latter can be summarised as follows: climate neutral buildings are only feasible if the fundamentals on the passive side – good insulation, air tightness and the avoidance of cold bridges – have been addressed and, at the same time, active components for energy production have been integrated into the building. The interviewees were also in agreement that buildings should prioritise user comfort and that the future lies in neighbourhood-wide energy concepts.

There is probably little point in debating the principles of ‘Active’ versus ‘Passive’ in a purely theoretical manner or to discuss the economic viability of particular energy standards on the basis of abstract figures, as the answer will inevitably depend on the individual case in its specific context. Therefore, the focus of this edition of DETAIL Green will be, as usual, on analysing exceptional case studies with various uses – from a holiday home to a former grain silo – in the hope that these will far outlive the current heated debate over sustainable principles.

Jakob Schoof

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2014 ¥ 1 ∂Green

Something in the air: the spirit of activism in young architects Oliver Lowenstein

Maybe there is something in the air or, perhaps more likely, it might be due to the on-going repercussions still being felt from the financial crisis of 2008. But one year on from the protests on Istanbul’s Taksim Square, the new tide of politically engaged younger architects shows no signs of waning. This new wave of ‘activist’ architecture comes in many shapes and sizes, but seems primarily driven by social conscience, as well as by political, ethical or ideological concerns. It is based on a perception that all too often, design has become commercially and aesthetically disconnected from grassroots needs. One may not agree with humanitarian architect, Anna Heringer – one of the most visible of the wave of ‘committed’ young practitioners – when, with utter conviction she states, “iconic ‘starchitecture’ is over.” But hardly anyone would dispute that iconic projects – and more generally the pre-crash consensus in the commercial building industry where speculation was unbridled – have become questionable nowadays.

Some people see these as being parallel echoes of the last great period of architectural activism: the 1960s and 1970s community and housing movements, the

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era of vernacular rediscovery and the rejection of the Modernist canon, the high tide of counter-culture, as well as the beginnings of a first generation of contemporary environmental architecture after the 1973’s oil crisis. Yet, for many the zeitgeist is fundamentally different. Architects are media savvy and web-wise, and less enamoured with oppositional activism. In contrast to the late 1960’s current generations eschew rioting and departmental takeovers to demand the overthrow of capitalism. Instead, a perceived smartness, a strategic focus, and what some call ‘propositional’ approaches have become far more popular. Participation and attempts to democratise the building’s design process have become the trend, as well as a focus on direct, physical ‘making’. Often, new generations of architects gain first-hand practical experience while they are still studying. The result is an emphasis on the process rather than on the final building, with projects often taking far longer than commercial imperatives would normally allow for. The same imperatives (which some in the mainstream have described as ‘social worker’ architecture) have also led to an increasing number of western-educated archi-

tects to work in small communities across the developing world. It is here, in particular, that small, participatory low-tech projects can, with enough personal energy, actually be realised. With the shifting axis of power from the old West to the emerging economies, the international dynamics are very different than they were four decades ago. None-the-less, what animates today’s activism is essentially the same as in previous years: conscience, passion, outrage and justice, to name but a few constants that have remained throughout human history.

Portugal – Front line architectural activism Most immediately, in those countries ravaged by economic collapse on the European continent today, such as Portugal, Italy, Greece and Spain, new forms of architectural practice are emerging. After the economic growth in the early 2000’s, the downward turn has left a decimated architectural profession, particularly among young graduates, with unemployment at an all time high. In Spain and Portugal particularly, a shift in sensibilities is evident; a new generation of architects has been at the forefront of extending architecture’s reach. In Portugal, the IMF’s 78 billion euro bailout in the summer of 2011 was a key moment in the emergence of this generation; with experimental practices, such as ateliermob, LIKEarchitects and Arteria working locally in the capital, Lisbon, and the country’s other urban centre, Porto. When Arteria’s founding member, Ana Jara, returned from working abroad in 2009, she found a country in “total crisis.” As her generation had no way of getting work, she was led, like others, to “go to the streets proposing projects.” Arteria have carved out a corner in urban renewal and the rehabilitation of old buildings in the run-down capital centre, including the 2012 Edifficio Manifesto, where they worked with a neighbourhood association. Likewise, ateliermob are working on housing across impoverished Lisbon suburbs. The net-

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Oliver Lowenstein runs the UK Green Cultural Review, Fourth Door Review (www. fourthdoor.co.uk) and is a UK correspondent for DETAIL Green.

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work practice Exyzt completed a temporary multi-use, collectively built community space in Cova da Vapor (Vapour House), and continue to work with, and as part of, the local community; while Porto’s LIKEarchitects have created a series of pop-up installations in different towns and cities. Jara describes this wave of experimental young practices as small, and something which “most of the public are still unaware of. It has been, and still is, very difficult and these new collective ways of working still feel like pioneering.”

Awareness of these communities and social practices, were given a sizeable publicity platform thanks to last year’s Lisbon Triennial, Close-Closer. Beatrice Gallilee, the Triennial’s English chief curator, recalls first stepping off the plane and walking into “strikes, demonstrations, it was awake-up call for me, making me very aware of not being frivolous with the budget.” With minimal budgets, a wide range of small pop-up and performance work, as well as exhibitions with titles like, Planning for Protest, the event also fostered a debate about whether Portuguese architects should stay to rebuild a shattered country, or work abroad in the richer European North or in their former colonial

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countries, particularly Angola and Brazil with their booming economies.

Nordic experiments Socially conscientious approaches to architecture are not limited to southern Europe. They can also be found in the rich Nordic region, which has not faced direct economic crises, and is considered to be a model of advanced social democratic organisation. One example can be found in Trondheim, Norway’s second major city, where an equally local, activist culture of architecture has rooted itself. Eight years ago members of the Svartlamoen district – an established alternative community in a run down part of the inner city – began an unlikely collaboration with student architects, Geir Brendeland and Olaf Kristoffersen. The pair, with involvement of Svartlamoen, developed an experimental timber student housing project on the strip of land on which the Svartlamoen community stands. The experimental, five-story housing block made of crosslaminated timber has since become one of the best-known recent Norwegian timber buildings. This was followed by another series of buildings by BKArk (as the architects’ office became known): a skilful

Rake Gallery, Trondheim Rake, 2011 ‘Edificio Manifesto’ community building, Lisbon Artéria, 2013 Casa do Vapor, Lisbon Exyzt, 2013 Klong Toey Community Lantern, Bangkok TYIN Tegnestue, 2011

and sensitive participatory redesign of an interior car showroom for Svartlamoen’s kindergarten; a recording studio and rehearsal spaces inside another old building in the area; and, more recently, resident-artist, Vigdis Haugtrø’s self built art/ community house project, Husli, constructed entirely from timber palettes.

While Haugtrø’s artistic background highlights the interactions between architects and artists common across this terrain, Svartlamoen is also home to the artist-architect collective, Rake. Their cross-disciplinary approach is well illustrated in the student-run design/build project, carried out together with members of Svartlamoen, which resulted in Rake Gallery, a temporary art space on the other side of town, with an outer facade created completely out of window frames. Conceived by the architect half of Rake’s couple-led team, Trygve Ohren, the art space was a surprise runner-up in the EU-sponsored, 2013 Mies van der Rohe architectural awards. Ohren is now mid-way through designing a new group of experimental housing for Svartlamoen.

Another of the new young Trondheim practices, TYIN Tegnestue, have become known on the wider world stage as ‘humanitarian architects,’ with their Safe Haven orphanage on the Thai-Burmese border and the Cassia co-operative centre in Sumatra, which brought them considerable attention and praise, although the founders would rather not be such pigeon-holed. In an email response to this label, ‘humanitarian architects’, TYIN’s Andreas Gjertsen notes that they are not activists, but more emphatically that, “the whole idea about ‘humanitarian architecture’ doesn't really apply to what we do, neither now or earlier.” Seemingly to discredit any such expectations TYIN are currently finishing Trondheim airport’s tax-free interior design.

When I relay some of these aspects to Anna Heringer, the German architect, she looks puzzled for a moment across the Skype video link, before saying with a

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Projects

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A large building with a small footprint Faculty building in Baltimore Behnisch Architects, Stuttgart/Munich/Boston with Ayers/Saint/Gross, Baltimore

Floor plan Scale 1:1000

Prominently located at the northern entry to the city centre and the university campus of Baltimore, the John and Frances Angelos Law Center unites classrooms, faculty offices, and law library under one roof. Behnisch Architects − who received the commission after winning an international competition − designed a compact 17 800 m2, eleven-storey building that bears some resemblance to their celebrated Genzyme Center in Cambridge, Massachusetts. The Law Center is composed of three interlocking, L-shaped volumes that serve the different functions of the programme (classrooms and offices, ‘legal clinic’ and law library). A narrow atrium rises up through the heart of the building, connecting the different spaces and supplying daylight to the rather deep interior spaces. The roofs spaces on top of the three volume setbacks have been

planted as roof terraces that provide views across the skyline of Baltimore.

Inside the building, glazed partition walls transmit daylight deep into the offices.

Classroom partitions are partly glazed as well, creating visual continuity between teaching spaces and public areas.

The three-part structure of the building also allowed the architects to deal with the varied requirements for floor-to-ceiling heights in the different spaces. Floor slabs in the three volumes are thus situated at different levels, which create interesting diagonal vistas across the atrium.

The outside of the building is clad with three distinct facade types − the office/ classroom facade, the library facade and the atrium facade. Offices and classrooms were clad with aluminium unitised wall panels. These are punctuated by (partly operable) window openings, some

of which are extremely large in size. An additional curtain wall made from frameless glass protects the facade and, particularly, the external shading devices from high winds.

Likewise, the library facade on the upper levels of the building consists of a unitised wall system, albeit a with more regular window pattern and without an additional rainscreen. Half of the facade panels are covered with a white ceramic frit, part of which was applied at a custom gradient to create a three-dimensional ‘woven’ effect. The atrium facade, in turn, is fully glazed and supported by a steel frame that spans between the three adjoining volumes. Automatically-operated flaps on each floor level draw in fresh air to the atrium and serve as air inlets for the smoke exhaust system.

Expected to achieve LEED Platinum certification, the building has a primary energy demand of 125 kWh/m2a, which is equivalent to 43 % energy cost savings over an ASHRAE 90.1-2004 base building. Rooms are primarily heated and cooled via concrete core activation of the floor slabs and are supplied with fresh air by a hybrid ventilation system. During hot or cold periods, a MVHR system with enthalpy wheel heat recovery operates. None-theless, windows in offices, classrooms and the library can be opened at any time, with a green light alongside the operating switch indicating whether exterior conditions are favourable. The new-build has LED lighting throughout (which includes the wing-like ‘chandeliers’ in the atrium) and is equipped with a 25,000-gallon rainwater-harvesting tank.

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Bastion of peace Office building in Copenhagen 3XN, Copenhagen

Ground floor plan

Since the summer of 2013, Copenhagen’s North Harbour has been home to an international workforce of around 900 employees from 104 nations. They work in 3XN’s ‘UN City’, the United Nations’ new regional headquarters that bring together the employees of eight UN organisations, affiliated agencies and international organisations. The site – an artificial island formerly occupied by warehouses – proved to be ideal to achieve the client’s somewhat contradictory requirements of security, accessibility, visibility and a degree of openness. The eight-pointed star shape of the building, “is a clear visual reference point, which, like the UN, reaches out to all corners of the world,” stated the architects. Echoing the surrounding rusted piers, the ground floor of the building – which contains all communal functions – is clad in dark burnished steel

panels. In contrast, the five office floors rising above have light perforated aluminium shutters that fold outwards to control the amount of daylight entering the rooms.

Since the facade is subdivided into threemetre-long modules, the employees can control the sunshades adjacent to their respective workplaces directly from their computers. This not only gives them more control of their individual environment, but also provides the building with a dynamic facade expression.

An atrium at the heart of the building connects all the floor levels. The atrium contains a sculptural staircase, which, according to the architects, “is to be seen as a symbol of the UN’s work to create dialogue [...] between people in all parts of the world.” Alongside this, the UN City has more than 90 meeting rooms including a number of multipurpose rooms on

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each floor, as well as an auditorium with a seating capacity of up to 450 people.

With a primary energy consumption of less than 50 kWh/m2a, the new-build conforms to Energy Class 1 according to Danish building legislation, and has been registered with the LEED sustainability rating system with the goal of LEED Platinum certification. More than 1400 solar panels have been installed on the flat roof and are predicted to generate 297,000 kWh per year. Cooling is provided by cold seawater that is pumped into the building’s cooling system, thus almost eliminating the need for electricity to power the cooling cycle. Furthermore, lowflow water taps were installed throughout the building and pipes on the roof capture almost 3000 m3 of rainwater annually; almost enough to flush all the toilets in the building without using potable water.

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Publications/Events

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Vitamin Green Phaidon, London 2012. 352 p., ISBN 978-0-714-86229-3. £ 45.00 Phaidon’s publication, Vitamin Green covers a wide range of topics and projects ranging from Japan’s first Passive House and the Tesla Roadster electric vehicle, to a network of floating schools on boats in Bangladesh. Exactly 101 examples of sustainable architecture and design are documented in this volume. Some of these raise questions about whether our society is on the right track towards the future. Is biomass heating truly sustainable in our age of deforestation? Does it make sense to laminate PV cells onto handbags, which will most likely end up as electronic waste one day?

Design Education for a Sustainable Future Rob Fleming. Earthscan by Routledge, Abingdon/New York 2013. 235 p. ISBN 978-0-415-53766-7. £ 29.99 Few would deny that the new sustainable paradigm in architecture also requires a change in the content and methods of architectural teaching. Yet uncertainty still prevails as to what precisely this change should entail and how it might be implemented. With his new book, Rob Fleming now provides systematic guidance on this issue. Drawing on numerous resources, including his many years’ worth of teaching experience, the author presents a (nearly) all-encompassing tour d'horizon of the topic, ranging from a brief history of

Intelligent Buildings Derek Clements-Croome. Earthscan by Routledge, Abingdon/New York 2013.

218 p. ISBN 978-0-415-53113-9. £80.00 What exactly is it that makes buildings ‘intelligent’? The answer given by Derek Clements-Croome and his co-authors in this book lies just short of ‘everything’: “Intelligent buildings should be sustainable, healthy, technologically aware, meet the needs of occupants and business, and should be […] adaptable to deal with change.” Intelligent buildings provides a short and well-structured overview of the processes and strategies that can deliver these qualities – from integrated planning teams to intelligent building controls, BIM and post-occupancy evaluation. Although

With regard to the buildings presented in the book, many of the projects (such as SANAA’s Zollverein School or Foster and Partners’ Masdar City in Abu Dhabi) are already known to architecture enthusiasts. None-the-less, Vitamin Green does contain a number of interesting ideas and inspiring examples that make the book a worthwhile read. The texts are well researched and well written, and the illustrations are both appealing and informative. Above all, the book provides an insight into the wide range of issues throughout the world and also looks at the huge range of potential solutions that thoughtful design can offer. In doing so, this publication challenges the creativity of architects and designers and, at the same time, illustrates the importance of their role in shaping sustainable lifestyles.

architectural teaching and changing mind-sets in architecture, to concrete recommendations on new forms of teaching and collaboration in architecture schools.

The combination of an insightful theoretical vision (based on Ken Wilber's Integrative Theory, amongst others) and practical knowledge is one of the strengths of this book. The only minor weakness is the (relative) scarcity of case studies, which might, in some instances, have been helpful for more practically-minded readers. However, Fleming deliberately chose not to show any buildings or designs, but rather illustrates his concepts with numerous (and inspiring) diagrams. Overall, Design Education for a Sustainable Future should be read not just by university lecturers, but by anyone who is concerned about architectural education in general.

the chapters were written by as many as 15 different authors, they complement each other well and – with one or two overly academic exceptions – convincingly argue for buildings to be designed and operated with a long-term perspective in mind. Further insight is given by a number of case studies on a wide range of topics – from the engineering work of Buro Happold and the post-occupancy evaluation of educational buildings to the design of sustainable skyscrapers.

The book is targeted mainly at investors and prospective proprietors but, with its prohibitive price tag, is unlikely to attract a wider audience beyond this target group. This is regrettable as its content is highly recommendable to all those interested in how to translate intelligent buildings and integrated design into reality.

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May 2014 Solarexpo Congress and exhibition on renewable energies, energy efficiency and sustainable architecture 7.5.2014 –10.5.2014 Milan/Italy www.solarexpo.com International Concrete Sustainability Conference 12.5.2014 − 15.5.2014 Boston/USA www.concretesustainabilityconference.org All-Energy 2014 Trade fair on renewable energies 21.5.2014 − 22.5.2014 Aberdeen/UK www.all-energy.co.uk Sustainable City 2014 9th International Conference on Urban Regeneration and Sustainability 23.5.2014 − 25.5.2014 Siena/Italy www.wessex.ac.uk/14-conferences/ sustainable-city-2014.html Resilient Cities 2014 5th world congress on cities and adaptation to climate change 29.5.2014−31.5.2014 Bonn resilient-cities.iclei.org ICAE 2014 6th International Conference on Applied Energy 30.5.2014 − 2.6.2014 Taipei/Taiwan www.applied-energy.org

June 2014 Building Lasting Change National conference and expo of the Canadian Green Building Council 2.6.2014 − 4.6.2014 Toronto/Canada www.cagbc.org/AM/Template. cfm?Section=National_Events Intersolar 2014 Trade fair on solar technology 4.6.2014–6.6.2014 Munich/Germany www.intersolar.de 14th Architecture Biennale International exhibition on architecture Theme: Fundamentals 7.6.2014 – 23.11.2014 Venice/Italy www.labiennale.org

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The Third World Construction Symposium Conference on sustainability and development in the built environment 20.6.2014 − 22.6.2014 Colombo/Sri Lanka 2014.ciobwcs.com Solar Decathlon Europe Student competition for zero-energy buildings 27.6.2014 − 14.7.2014 Versailles/France www.solardecathlon2014.fr/en

July 2014 Intersolar North America Trade fair on solar technology 8.7.2014 − 10.7.2014 San Francisco/USA www.intersolar.us Green.Building.Solutions Vienna Summer University 26.7.2014–17.8.2014 Vienna/Austria www.inex.org/study-abroad/greenbuilding-solutions-vienna/

August 2014 UIA World Congress 2014 World Congress of the International Union of Architects Theme: Architecture Otherwhere 3.8.2014 − 8.8.2014 Durban/South Africa www.uia2014durban.org

September 2014 RENEXPO Poland Trade fair and congress on renewable energy and energy-efficiency 13.9.2013 − 25.9.2014 Warsaw/Poland www.renexpo-warsaw.com Klimamobility 2014 Specialist trade fair for sustainable mobility 18.9.2014 – 20.9.2014 Bolzano/Italy www.fierabolzano.it/klimamobility EU PVSEC 28th European Photovoltaic Solar Energy Conference and Exhibition 22.9.2014 − 26.9.2014 Amsterdam/The Netherlands www.photovoltaic-conference.com

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October 2014 CEB Clean Energy Building Expo 6th international exhibition and conference for energy-efficient and intelligent building 15.10.2014 − 16.10.2014 Budapest/Hungary www.cep-expo.hu SAIE 2014 49th Innovation Building Exhibition 22.10.2014 − 25.10.2014 Bologna/Italy www.saie.bolognafiere.it/en/ 9. Energy Forum Congress on solar building envelopes 28.10.2014–29.10.2014 Bressanone/Italy www.energy-forum.com

November 2014 RIFF Architecture Conference Conference on architecture and habitat 10.11.2014 − 11.11.2014 Bucharest/Romania www.ieriff.ro RENEXPO South East Europe Trade fair and congress on renewable energy and energy-efficiency 19.11.2014 − 21.11.2014 Bucharest/Romania www.renexpo-bucharest.com 2nd Passivhaus Portugal Conference Congress on energy-efficient architecture 29.11.2014 Aveiro/Portugal www.passivhaus.pt

December 2014 PLEA 2014 30th international PLEA conference; theme: Sustainable Habitat for Developing Societies 16.12.2014 − 18.12.2014 Ahmedabad/India www.plea2014.in

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2014 ¥ 1 ∂Green

Passive House or Active House?

Two competing building concepts Interviews with Wolfgang Feist and Manfred Hegger

The goal is clear, but the route is not yet clear. The experts are still debating the question of which concept would help achieve the European-targeted nearly Zero-Energy Standard both inexpensively and reliably. Will all new buildings in Europe be passive houses from 2021, or has the time come for the Passive House to be superseded by new, ‘Active House’ building concepts? Detail Green spoke with Wolfgang Feist, founder of the Passive House Institute, and Manfred Hegger, co-founder of the German association AktivhausPlus e.V..

Wolfgang Feist: Tackle the problems at source Mr Feist, EU building guidelines require that, from 2021, all new buildings in Europe will have to comply with the nearly Zero-Energy Standard. In your opinion, why is the Passive House an appropriate solution to meet this requirement?

Firstly, the Passive House continues the traditional path of development in the building industry, and contrary to some widely held beliefs, passive houses are generally planned and built in a very similar manner to conventional homes.

Secondly, the Passive House has already been around for over 20 years, during which time it has proven itself to fulfil its objective to reduce the consumption of fossil fuels. The Passive House addresses the root causes of energy loss in particular through the building envelope and ventilation systems, which

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also makes it a cost-effective solution. By comparison, the constant tinkering with symptoms is usually a more expensive option in the long-term.

Thirdly, passive houses offer great advantages in non-energy related issues: since the high levels of insulation protect the structure from temperature fluctuations and condensation they have a longer lifespan. They are also more comfortable and healthier than conventional buildings, as the residential ventilation system ensures a regulated air supply. These factors played a key role in the Passive House already becoming established in the 1990s, when energy costs were significantly lower than today.

Many architects and engineers are currently focused on concepts for so-called ‘Active Houses’, which aim to achieve a neutral CO2 balance without the need for achieving the Passive House Standard. What should we make of this?

In principle, every practical solution that aims to limit climate change should be viewed positively. However, these solutions have to be considered carefully. In my opinion, it makes no sense to build a relatively inefficient building and then to heat it with wood just to achieve a neutral CO2 balance. After all, the natural resource of wood as a fuel is very limited and should – if at all – only be used in combined heat and power plants.

Care also needs to be taken to consider all energy uses in buildings. It makes little sense to only consider the energy demand for heating, warm water and auxiliary power for ventilation and pumping, as set out in the German Energy Savings Ordnance (EnEV) and most other national energy regulations. Nowadays, a building’s electrical requirement is often a much more significant factor, which, however is usually left out of the equation. Therefore, I would be dubious of concepts that provide for an excessive heating requirement using a heat pump, and then compensate the electrical demand of the latter with a roof mounted photovoltaic system. After all, the photovoltaic electricity will be needed first and foremost to cover the electrical requirement for lighting and household appliances.

Up until now, the sole aim of the Passive House Standard has been to achieve the most energy efficient building services possible, while completely disregarding the CO2 balance. Are there initiatives which aim to develop the standard further in this direction in future?

We are not ignoring the CO2 balance, but rather using non-renewable primary energy sources as the key criterion for evaluation. This includes nuclear generated electricity, which would not be taken into account in a purely CO2 balancing exercise.

In theory – as is also the case in France and Great Britain – very favourable CO2 balances can be achieved when carried out to a large extent using atomic energy but, as we all know, this introduces a whole other set of ecological problems.

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Wolfgang Feist studied physics and founded the Passivhaus Institute in Darmstadt, Germany in 1996. Since 2008, he has been professor for Building Construction, Building Physics and Building Systems Engineering at Innsbruck University.

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querkraft architekten: residential building in Vienna (Passive House Standard) Ramona Buxbaum Architects: speech therapy school in Griesheim, Germany (Passive House Standard) Hermann Kaufmann Architects: office building in Dornbirn (Passive House Standard)

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Certainly non-renewable, primary energy sources also have limits as evaluation criteria. In Germany, the increasing amount of electricity from renewables has caused the primary energy factor for electricity to drop, with the result that, in an evaluation, the very same building suddenly looks much better than it previously did. This means that no reliable measure can be formed. For this reason, at the Passive House Institute we are working towards a new evaluation method based on a completely regenerative energy supply in the future. Most buildings built today will still be standing in 2060 or 2080. The question is: how will the energy performance of a specific building look when Germany’s entire energy supply is 100 % renewable?

to install it in a new building. In future, I would expect to see further reductions in the price of ventilation systems. On the other hand, there will be relatively little movement in the price of thermal insulation, where there are already very cost-effective solutions on the market. Here, we are working with manufacturers to develop low thermally-conductive solutions for uses like, for example, connections between building components.

It is widely held that to insulate every single house to Passive House Standard would be excessive and that, instead, neighbourhood-wide solutions should be prioritised. How would you respond to this?

Without a doubt, neighbourhood-wide solutions will be needed as well. There are always two sides to it: energy supply and energy demand. With regard to energy supply, comprehensive communal solutions are not only more cost effective, but are often the only way to achieve a Zero or Plus-Energy Standard at all. With enough photovoltaic modules and a little effort, a detached, single-family home can be transformed into a Plus-Energy House. On the other hand, this is practically impossible with large buildings located in city centres. Here, comprehensive regional solutions are needed. Just as cities rely on their hinterland as a source of food supply, the same goes for renewable energies. There is no point in opposing this, as it would be a big

In future, will you allow embodied energy from building construction to be included in the evaluation?

I have noticed that the current discussion of embodied energy is essentially a rivalry between different manufacturers who want to present their products in the best possible light. We prefer to distance ourselves from these conflicts. Of course we have considered this issue and have established two facts: when one considers the total energy consumption of an average new building, built to current construction standards, over its entire lifespan, the operational heating and electricity consumption plays a more significant role than the embodied energy.

On the other hand, the lion’s share of embodied energy usually relates to the load-bearing structure while the building envelope only accounts for a smaller portion. This contradicts the widelyheld belief that vast amounts of embodied energy are contained in the additional insulation used in passive houses. For this reason, we find it unpractical to ask building owners to submit a complete life cycle assessment just because of the additional five or six per cent embodied energy in a Passive House.

How high would you estimate the average additional costs for a multi-family Passive House compared with a building that is built according to the statutory German energy standard (German Energy Savings Ordnance, EnEV)?

Currently, an honest estimate would be around 75 Euro per square metre of usable area. By ‘honest’, I mean comparing like with like. If you use a particularly cheap construction method for a Passive House, you must, of course, assess this next to a comparable EnEV-compliant building. However, to build passive houses at such low additional cost requires some experience; this is not something everyone can accomplish. Thus, one of our main goals at the Passive House Institute is to spread the knowledge of how to build cost-effective passive houses.

In future, the continuing development of building components will bring the cost closer to that of conventional buildings. Tripleglazing, for example, now costs only slightly more than doubleglazing on the German market. So there is hardly any reason not

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2014 ¥ 1 ∂Green

Office building in Agoura Hills Form follows (air)flow

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Agoura Hills is a prosperous town with around 20,000 inhabitants approximately 45 km northwest of downtown Los Angeles.

The main arterial road linking the town to Los Angeles is lined with gas stations, fast food restaurants and shopping malls.

A short distance further west, however, the landscape changes dramatically: the buildings dissipate and the topography rises in the direction of the Santa Monica Mountains, which separate the valley of Agoura Hills from the Pacific Ocean.

The Conrad N. Hilton Foundation has chosen to build their new headquarters at the foot of this mountain range. It was the founder of the homonymous hotel chain, Conrad Hilton, who, 70 years ago, started the foundation that bears his name. Since then, the charity has donated nearly a billion US dollars to eleven causes including: substance abuse prevention for teens, disaster relief, as well as aid for the homeless and AIDS orphans.

The Hilton Foundation plans further expansion in the future: the

masterplan by ZGF Architects comprises a total of four office buildings with more than 8,000 square metres of total surface area on the 18-hectare site. With the completion of the first new building in 2013, the architects have set a high standard in design, as well as in sustainability for the foundation’s future building projects.

A showpiece for sustainable design The foundation headquarters accommodates a workforce of just over 50 people. Most of the staff work in private offices along the north and south facades; administrative support staff are arranged in cubicles at either end of the central circulation zone.

Additionally, there are two conference rooms on the ground level, as well as a third one on the upper level. In the entrance lobby and at the northwest end of the building, stairs and lofty double height spaces connect the two office levels with one another.

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Client: Conrad N. Hilton Foundation, Agoura Hills Architects: ZGF Architects LLP, Los Angeles Construction management: Bigelow Development Associates, Malibu Structural engineering: KPFF Consulting Engineers, Los Angeles MEP engineering, energy consultant: WSP/Built Ecology, San Francisco Landscape architect: Van Atta Associates, Santa Barbara

Phase 3

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Eastern elevation Site plan Scale 1:5000 Northern facade with recreation courtyard (looking east) Ground floor plan Scale 1:750 Upper floor plan Scale 1:750

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Office building in Agoura Hills

2014 ÂĽ 1 ∂Green

17 Northern side of the building with the covered courtyard 18 Sectional detail of the office facade Scale 1:50 a Ventilation grille, aluminium, 50 mm; on aluminium support frame b Roof: Green roof tray system, 108 mm; single-ply PVC waterproofing membrane, 1,4 mm; roof board, 6,3 mm; PIR rigid insulation laid to falls; in-situ concrete roof slab, 158 mm, on trapezoid sheet metal 1,3 mm; void/insulation, 330 mm; suspended acoustical panel ceiling, 27 mm c Facade: Unitized aluminium curtain-wall facade with double glazing d Exterior roller shade with stainless steel micro blades e Reveal, aluminium plate f Underfloor radiator g Floor slab of upper floor: Carpet tile, 7 mm; access floor system, 457 mm; in-situ concrete slab, 158 mm, on trapezoid sheet metal 1,3 mm; air void/insulation, 330 mm; suspended acoustical panel ceiling, 27 mm h Ground floor slab: Carpet tile, 7 mm; access floor system, 457 mm; reinforced concrete slab, 152 mm; vapour barrier, 1 mm; sand bed, 100 mm; gravel fill, 180 mm 19 Steel frame in the central circulation area.

The clerestory windows also provide exhaust ventilation for the building.

20 View of a typical office 21 Sectional detail of a downdraft shaft Scale 1:50 i Ventilation chimney: Adhered quartz stone veneer, 25 mm; epoxy mortar; cement board, 25 mm; stainless steel framing, 64 mm; spray-applied waterproofing membrane, 1 mm; reinforced concrete wall, 305 mm; installation shaft, 762 mm; stainless steel framing, 64 mm; painted gypsum board, 13 mm

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Internal insulation of external walls: design guidelines and system selection Daniel Zirkelbach, Hartwig Künzel

In the climatic conditions of central Europe, the insulation of external walls is one of the most important and effective energy saving measures in buildings. In terms of building physics, external insulation is particularly reliable and unproblematic, as the solid wall protects the insulation from moisture diffusion from the warmer interior and cold bridges are easily avoided. Nevertheless, in recent years internal insulation has gained in importance. This is due to the fact that, for many buildings previously without insulation, the application of external insulation is not possible or is undesirable as the buildings are protected structures, have a historically listed facade, or for other reasons. Buildings which are only partially or temporarily used (for example function rooms or churches), localised or short term heating combined with internal insulation is often more useful and cost efficient than permanent heating of the entire building. Furthermore, with short-term use, the solid building elements do need to be heated. This results in shorter preheating times and lower energy requirements. Similar advantages apply to tem-

1

porarily used areas in residential buildings.

With the design and simulation tools available today, internal insulation no longer poses any great difficulty in most cases.

However, criteria for good performance are: the selection of appropriate materials, possible associated works, especially in relation to rain resistance and high quality installation. This article presents the current thermal and hygric requirements and gives an overview of advantages and risks, as well as applicable materials and systems.

Energy requirements In Germany, the DIN 4108 standard determines the ‘hygienic’ minimum thermal insulation (which is necessary to prevent mold growth) for external building elements of residential and office buildings.

A building element is deemed to comply when its R-value is at least 1,2 W/m²K or if its fRsi-factor according to DIN 4108-2 is a minimum of 0,7 [1]. In this case, it can be assured that with a room temperature of 20 °C and a relative humidity of 50 % the temperature of the inner wall surface

will not drop below 12,6 °C even in corner junctions and around cold bridges and that the relative humidity will not exceed 80 %. With higher humidity levels on the wall surface, there is a risk that mildew will begin to form.

In order to avoid damage and hygienic problems, these requirements should always be observed − they also apply to protected structures with internal insulation. In addition, building elements that penetrate the insulation (for example internal walls or floors) require insulating wedges (Fig. 2), and additional insulation must be applied on window reveals.

Logically in renovation work, one would usually strive for a significantly improved level of insulation. The current German energy savings directive (EnEV 2009) requires a U-value of 0,35 W/m2K for building elements with internal insulation. To achieve this, a hitherto uninsulated wall with an R-value of 0,39 m²K/W requires an additional layer of insulation of up to 14 cm (Fig. 3).

It is currently under debate in Germany as to whether to discard this requirement, as in some cases such depths of insulation are difficult to achieve. However, this seems a somewhat excessive measure given the increasing availability of thin, high-performance insulation and the large amount of building stock that does not have a problem in this respect.

In any case, the EnEv requirements do not apply to protected structures. Nevertheless, the minimum practical measures should certainly be applied, as the first few centimetres of thermal insulation are the most effective against heat loss. Furthermore, especially with internal insulation, even small depths can make significant improvements to internal comfort levels and can reduce the risk of mildew, as the surface temperature of the wall is higher.

Hygrothermal performance As is already indicated above, applying an external insulating layer is particularly

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4 Research and practice

1

Inside

2

3 Insulation wedge

Internal insulation

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Insulating wedges to improve the fRsi-factor at the junction of an adjoining interior wall Required thickness of internal insulation to comply with EnEV 2009, depending on the thermal conductivity of the insulation. The previously uninsulated wall had a R-value of 0,39 m²K/W. Frieden school in Schweinfurt, Germany: interior view of a classroom. The external walls (left on the image) were insulated with capillary active calcium silicate panels.

Calculated moisture content (distributed over the thickness of the wall) in a 29-cm-thick solid brick wall with low resistance to driving rain, depending on the orientation of the wall.

Simplified evidence of condensation resistance of internal insulation types according to WTA data sheet 6–4. The diagram shows the required sdvalue depending on additional R-value of the new internal insulation, as well as the absorption coefficient (w-value) of the wall

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Daniel Zirkelbach is deputy director of the Hygrothermics Department at the Fraunhofer Institute for Building Physics (IBP) in Holzkirchen, Germany.

Hartwig Künzel is head of the Hygrothermics Department at Fraunhofer IBP. He participates in international standards committees and expert panels of ASHRAE and CEN, as well as teaches ecological building at the University of Stuttgart.

or when hydrophobisation is unsuitable for an exposed masonry structure. Then the only remaining option − at least on the most exposed facade − is to reduce the thickness of internal insulation to just a few centimetres, which in terms of drying out is a negligible amount. Such cases, however, are an exception.

If an exterior wall is identified to have a problem with rising damp, improvements should be made before internal insulation is applied in order to limit the source of damp from below and to permanently improve the drying out process (for example with a specialised restoration plaster).

1,0

EnEV requirement λ = 0,020 W/mK

0,6

0,4

0,2

0 4

6

8

Moisture content [Vol.-%]

3

Which internal insulation systems are available?

Figure 8 gives an overview of a typical internal insulation system and its hygrothermal performance in both summer and winter. On the left hand side, the diagram shows mineral fibre insulation that allows diffusion without any vapour barrier. Condensation can form on the cold rear surface of the insulation in winter. With an absorbent substrate this is acceptable up to a certain point, even though it creates additional dampness in the existing wall.

Dampness caused by rainfall or condensation can, however, dry out well in summer internally through the open insulation.

Nevertheless, this kind of solution is only acceptable up to a thickness of a few centimetres in order to improve indoor comfort and prevent mold growth.

Where there is a greater depth of insulation, an additional vapour retarder is required. This significantly reduces the risk of damp by diffusion in winter. In some cases however, vapour retarders with uniform diffusion resistance can compromise the required internal drying out in summer. If the masonry is damp they can even cause interstitial condensation to form within the insulation.

In principle, vapour tight rigid foam insulation without an additional vapour retarder behaves similarly. In winter it provides protection against dampness from the in-

λ = 0,040 W/mK λ = 0,060 W/mK

0,8

10 12 14 Insulation thickness [cm]

16 West 12

8

4

North

0 0 Outside

7

14

4 Sdi-value [m]

straightforward. This is due to the fact that the solid wall construction acts as a vapour barrier and hence the insulation generally remains unaffected by condensation. The existing wall within the insulating layer remains warm and dry throughout the year due to the effective rain screen provided by the external insulation system.

In the case of internal insulation, this process is reversed: the wall is colder than it previously was and is therefore inevitably damper. With the installation of a thicker insulation layer, the temperature at the rear of the insulation will usually drop below the dew point temperature of the interior. For this reason, diffusion of moisture into the wall ought to be limited, whilst rear ventilation of the insulation with air from the room ought to be avoided at all costs. These requirements are, however, very similar to lightweight construction (roofs, timber walls) and should be achievable with careful design and installation.

Nowadays, the critical factor with internal insulation is not the risk of damp entering the wall from the inside, but rather from the outside. The exposure to driving rain is especially significant. Older structures often have poor resistance to driving rain.

In particular, facades with westerly exposure are subject to high levels of dampness, as the example in Figure 4 indicates.

If internal insulation is applied to a wall like this without appropriate measures, the far slower rate of drying out can lead to damp penetration or to frost damage.

Appropriate measures for improved protection against driving rain include, for example, the application of a new water resistant paint or plaster finish and the hydrophobisation of the facade to improve water repellence. In any case, the external envelope should be improved to make it as rain resistant as possible whilst still allowing diffusion.

In some cases, however, this is not possible, for example with protected facades

U-value [W/m2K]

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Minimum insulation acc. to DIN 4108 0,5

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2014 ¥ 1 ∂Green

Electrochromic glazing: properties and design guidelines John Mardaljevic, Ruth Kelly Waskett, Birgit Painter

The use of daylight in office buildings is generally considered to be a greatly under-exploited resource. To a large degree, this is due to the highly variable nature of daylight illumination. The natural variability in daylight means that users will often need to use shades to moderate excessive ingress of daylight. Alternatively, the building may have fixed structures to block, redirect, and/or attenuate the daylight, e.g. lightshelves, brise-soleil, or fixed-tint glazing.

With moveable shades, the users rarely make the effort to adjust them once the external conditions have changed. Thus, the shades are often left closed for much of the day, resulting in the commonplace occurrence of ‘blinds down, lights on’.

Controlling daylight There are essentially three ways to control daylight from facade windows: • Block the light (e.g. opaque roller blinds).

• Redirect the light (e.g. reflective lightshelves, prismatic glazing, etc).

• Attenuate the light (e.g fixed-tint glazing).

Many shading devices – fixed and moveable – utilise two of the above mechanisms. For example, a lightshelf is usually designed to block direct sun near to the

2

window and also redirect the (blocked) daylight to the ceiling where it can help to improve daylight penetration. Users can operate venetian blinds to both block and redirect light, though it is more common to see them used with the slats closed.

Importance of view Another key consideration is the mode of transmission: specular, diffuse or a mixture of the two. This is particularly important for primary view windows.

A specular transmission is one where the light rays exhibit no noticeable deviation, and thus the view always appears sharp.

For example, even with heavily tinted glazing, the view to the outside will appear sharp, albeit darkened, during the daytime. However, if the glazing is of the diffusing type (e.g. a privacy screen), then the light rays are scattered and there will be no discernible view. Some transparent materials exhibit both specular and diffuse properties, and the quality of the view through them will depend on the relative proportions for the two transmission modes. Note that most occupants find that even a small degree of scattering by glazing is unacceptable for primary view windows.

Slatted blinds (i.e. horizontal or vertical) can be adjusted to allow a partially obstructed view out. However, depending

on the particular configuration of the slats and the distance from the window, the occupant may find that their focus is drawn to the slats, thus making it difficult to gain the beneficial relaxation of the eyes that is afforded when they are focused on the distant view beyond. This effective ‘shortening’ of the distant view can also occur with external shading structures such as brise-soleil.

Glazing with a transmissivity that varies continuously between clear and dark extremes could offer a far greater degree of control over the luminous environment and avoid many of the drawbacks of the traditional approaches to shading and solar protection. In contrast to fixed-tint glass, a variable transmission glazing would modulate the daylight in response to real-time conditions, rather than simply attenuating it by a constant fraction.

Variable transmission glazing The principle behind variable transmission glazing (VTG) is straightforward: the transmission properties of the glazing are varied to achieve an ‘optimum’ luminous and/or thermal environment. The various types of VTG can be grouped into three broad classes: chromogenic coatings, suspended particle device and microelectromechanical systems (though there are other types also under development).

VTG types and mechanisms In the chromogenic class there are four distinct types of formulations for materials that have variable transmission properties. These are: electrochromic, gasochromic, photochromic and thermochromic.

The agents causing the change in transmission are: voltage (electrochromic); concentration of pumped gas (gasochromic); localised illumination (photochromic); and, localised temperature (thermochromic) (fig. 1). Thermochromic and photochromic are essentially passive devices which respond to changes in the environment, whereas electrochromic and gasochromic are active devices that can

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Electrochromic

4 Research and practice

Thermochromic

Suspended particle device a) Tinted

Any sensor input

Localised temperature off

Gasochromic

Photochromic

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John Mardaljevic is Professor of Building Daylight Modelling at Loughborough University, UK. Ruth Kelly Waskett is a PhD student in daylighting at De Montfort University, Leicester, UK. Birgit Painter is a Senior Research Fellow at the Institute of Energy and Sustainable Development at De Montfort University.

b) Clear 1 Any sensor input Electrolyser

Localised illumination

Pump

~ AC

Chromogenic glazing types (left) and functional principle of suspended particle device (SPD) 2–3 Electrochromic glazing in clear and darkened state 4 Characteristics of different types of variable transmission glazing (VTG)

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be configured to respond to any sensor input, e.g. illumination, temperature, or a combination of the two.

Suspended particle device is a technology based on plastic film. The latter is in fact a thin layer containing a suspension of rod-like particles in billions of liquid droplets. An applied voltage alters the orientation of the particles and therefore the transmission properties of the film (fig. 1, right).

A VTG based on micro-electromechanical systems (MEMS) has tiny, micron-scale structures that move in response to an applied electrostatic field, thereby altering the transmission properties of the glazing.

VTG performance characteristics The key to performance for a VTG is a high (visible) transmission in the clear state and a sufficiently low (visible) transmission in the darkened (or tinted) state.

To be perceived as acceptable to the majority of occupants in non-domestic buildings, the VTG in the clear state should appear like ordinary (un-tinted) double glazing, and so have a visible transmission of 60% or greater. In the darkened state the transmission should be low enough in order that additional glare control is required only very rarely, or perhaps not at all. In practice, this means a minimum

visible transmission of around 2 % or less.

Additionally, the building occupants should have some degree of control of the glazing, e.g. to manually override an automated control setting. Experience has shown that occupants will often resort to sabotage if an automated building control system fails to do what they wish. So, whilst a ‘passive’ VTG might seem attractive at first because it allows for autonomous operating behaviour, the corollary of this is a lack of control, e.g. modulation of the glazing transmission by (localised) window temperature will not necessarily offer the luminous environment desired by the occupants.

There are examples of thermochromic glazing on the market, though the narrow visible transmission range (e.g. 13–60 % or 6–30 %) indicates that additional shading would be needed to control glare.

Thermochromic glazing therefore seems better suited to offering a degree of moderation of the thermal rather than the luminous environment. Gasochromic has the potential advantage of rapid switching speeds. A gasochromic system requires the glazing unit to be literally ‘plumbed-in’ – i.e. connected to an electrolyser and pump by piping. The practicalities of a gasochromic installation are such that the technology is still considered the preserve of research.

The situation regarding SPDs for clear (i.e. view) glass is uncertain. There appear to be some products on the market, but limited examples of actual installations. MEMS window technology is still undergoing development. Thus, of the technologies described above, only electrochromic (EC) glazing appears to have the necessary optical properties (i.e. wide visible transmission range), is relatively straightforward to install, is already in the marketplace, and is undergoing largescale production.

Electrochromic glazing The phenomenon of electrochromism has been known since the 19th century, and its application as a glazing technology has been investigated since the 1980s.

However, it is only recently with major new investment and scaled-up production that EC glazing has shown the potential to become a mainstream product [1].

User acceptance for any daylight control technology depends on a number of performance and operational characteristics. For EC glazing, these include performance with respect to glazing transmission range (i.e. the values for the maximum and minimum visible transmittances), the switching time between the clear and tinted states and the effectiveness of the automated control to VTG type

Visible transmittance

Solar heat gain coefficient

Electrochromic

1–60 % (SageGlass)

0.41–0.09

Thermochromic 13–60 % or 6–30 % (Suntuitive)

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Sustainable design teams, methods and tools in international practice Emanuele Naboni

The emphasis on the sustainable performance of buildings is redefining both the requirements for building design and the structure of architectural practices. Among international firms, the growth in sustainable expertise has led to the emergence of specialist teams in environmental simulation and sustainable design. In this context, environmental simulation is the catalyst of change: it impacts design processes and facilitates new models of collaboration with consultants and academic institutions.

Based on interviews with specialists from ten leading architectural practices, this article outlines developments in performance-based design and explores how these influence companies, as well as the design industry at large.

The teams In recent years, the so-called ‘greening’ of architecture has produced a new class of experts and professionals. Some of the world’s leading architectural practices have set up specialist teams with a focus on sustainability and performance-driven design (Fig. 3). The teams tend to be comprised of architects and engineers, but there are exceptions. The Specialist Modelling Group (SMG) of Foster + Partners (F+P) includes experts in mechanical and aerospace engineering, building physics, acoustics, art, and material science, who work alongside the architects. KieranTimberlake’s interdisciplinary research group takes advantage of expertise from environmental management, urban ecology, manufacture, chemical physics, electrical engineering, materials science, and marketing. Both groups include thinkers who are able to cross scales and disciplinary boundaries.

The specialist teams increasingly form parts of practices that primarily provide architectural services. However, practices with integrated engineering teams (e.g. SOM, and Stantec) also have dedicated ‘sustainability’ teams that focus on bridging the gap between architectural and engineering services. Irrespective of

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their structure, all specialist teams leverage the power of advanced modelling and environmental simulation to explore new frontiers of sustainable design. Teams work on multiple design projects, usually at early design stages, and engage in dialogues with design teams in order to define targets and design strategies (Fig. 2).

Research and dissemination An interesting phenomenon is the impact of the specialist teams upon the development of new green approaches, both within their offices and beyond. The groups act as forums for testing and developing new sustainable technologies. Using scientific approaches, they aim to deliver high-quality buildings that are comfortable and have a positive impact on the environment.

Statements like, “Our research shows that between 40 % and 50% of the energy consumption of a building is determined by the design.” by the Sustainable Design Team of Henning Larsen Architects (HLA), and similar statements by other firms, are indications of the expanding field. Their research results are disseminated through peer-reviewed conferences, journals and books. Teams participate and contribute to the organisation of conferences, mainly linked to modelling and simulation of buildings, such as IBPSA, ACADIA, SmartGeometry, and others. They produce books or professional articles of interest for the wider community of designers. For example, Adrian Smith & Gordon Gill Architecture (AS+GG), describe their approach to the decarbonisation of cities in their book Toward Zero Carbon: The Chicago Central Area DeCarbonization Plan, whilst HLA has published books such as What about Daylighting? [1] and Kjell Anderson of LMN Architects published Design Energy Simulation for Architects. Most recently, Perkins+Will established AREA Research [2], a non-profit research entity funded by Perkins+Will and other firms with the aim of sharing knowledge about the built environment. AREA Research is committed to the free public dissemination of all of its research findings.

Collaboration with other stakeholders In order to respond to the complex requirements of sustainability, the specialist teams engage in collaboration with educational institutions and research laboratories. New approaches, technologies and computational design methods are thus tested on real projects, hence bridging the gap between research and development on one hand, and practice on the other.

For example, SOM’s collaboration with Rensselaer Polytechnic Institute led to the foundation of the Centre for Architecture, Science and Ecology (CASE) [3], which focuses on the research of next-generation technologies that will enable self-sustaining buildings and urban developments (Fig. 1). Through this collaboration, SOM benefits from the work of researchers that apply methods rigorously, using a broader range of technical and the-

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Emanuele Naboni is Associate Professor of Sustainable Design at the Institute of Architectural Technology of The Royal Danish Academy, in Copenhagen. He was previously a researcher at the Lawrence Berkeley National Laboratory and Sustainable Design Specialist at SOM in San Francisco.

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Facade prototype developed by CASE and SOM. The solar facade contains solar concentrators that track the sun and simultaneously generate electricity, gather heat from water circulating through the system, and diffuse light coming into a building.

A dialogue based on daylighting opportunities between the sustainable design specialist and a design team at Henning Larsen Architects Specialist teams of some of the interviewed practices dedicated specifically to sustainable design and the use of simulation tools.

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Practice

Sustainability team

Primary focus areas of the sustainability team

Type of performed research

3XN

GXN

Life-cycle design; informed design; green building materials

Circular economy; green roofs; new build- Denmark ing materials; integrated building systems

75/10 (13 %)

Adrian Smith + Gordon Gill Architecture (AS+GG)

Sustainable Design Team

Performance design; life cycle cost; efficiency through density

USA Decarbonisation of cities; integration of renewable energies in high-rise buildings; development of parametric tools

100/5 (5 %)

Aedas

Aedas R&D, Sustainable Design Team

Operational energy; life-cycle design; Performance gap; post-occupancy evalu- UK/global performance modelling ation (POE); building performance optimisation; online software tools such as CarbonBuzz; policy and regulation

919/5 (0,5 %)

Foster + Partners

Specialist Modelling Group

Visual, thermal and acoustic comfort; airflow; embodied and operational energy; new building components

Performance visualisation; development of software tools; development of manufacturing methods for complex geometric forms; post-occupancy evaluation; urban microclimate; airflow simulation; new performance metrics; new building components

UK/global

630/20 (3 %)

Henning Larsen Architects (HLA)

Sustainable Design Team

Daylighting; energy; life-cycles of materials

Daylight and human health; urban microclimate

Denmark/ global

220/20 (9 %)

KieranTimberlake

All firm members engage in research. A dedicated transdisciplinary team is responsible for independent research projects.

Novel construction processes and materials; lightweight and highperformance building envelopes; cradle-to-grave energy reduction

Environmental analysis, building and site monitoring; bespoke modelling and simulation tools; prototypes; whole building concepts for extreme climates

USA

80/10 (12,5 %)

LMN Architects

Tech Studio

Daylighting; parametric modelling; optimisation

Digital fabrication; data visualisation; software interoperability

USA/Canada 91/3 (3 %)

Mario Cucinella Architects (MCA)

Sustainable Design Team, Computational Research Team

Performance design; daylighting; design optimisation

Digital fabrication; generative algorithms

Italy

25/4 (16 %)

Skidmore, Owings and Merril (SOM)

High Performance Design Studio and integrated design teams

High performance facades and systems with focus on comfort and energy; life-cycle design; sustainable neighbourhood development

Low-impact structural design; parametric analysis of building shape in relation to energy performance; water flows

USA/global

1100/30 (3 %)

Stantec

Energy; life-cycle cost; workflows in BIM/Energy Modelling Research Team and integrated high-performance building design design teams

Information exchange and communication USA/global workflow, high-performance building design methods

1125/10 (1%)

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Location(s)

Architects / Specialists 1)

Number of architects/designers in the office versus members of the specialist design team(s)

oretical knowledge than is commonly found among designers.

There are several other cases: Foster + Partners is part of a consortium set up by the European Space Agency to explore the possibilities of 3D printing to construct lunar habitat [4]. GXN, the research unit of 3XN, has received funds from the Danish Energy Agency to develop a new type of micro-perforated lamella in thermal windows together with the firm PhotoSolar [5].

Collaboration between Aedas, Hilson Moran and Arup has generated the ‘Tall Building Simulation’ (TBS) model. Today this tool is used by Aedas to assess the consequences of shape, form and briefing decisions for capital/life-cycle cost, as well as for operational and embodied carbon of tall buildings, early in the design process. Henning Larsen Architects and the Danish Building Research Institute developed A+E:3D [6], a publicly available software tool based on the Danish energy code BR10, which allows the calculation of a building’s energy demand already at the schematic design stage.

Wider scopes than certification system compliance Schemes such as LEED, DGNB and BREEAM are drivers for green design on the client side, but they barely impact the approach of design teams at the onset of a project. In general, sustainability specialists believe that certification presents an incomplete picture of the real environmental impacts of buildings; and that it inevitably leads to conventional solutions rather than encouraging innovation and architectural creativity. HLA explains in ‘Design with Knowledge’ [7] that the focus on mechanical systems, as promoted by rating systems, is less efficient than the optimisation of a building’s geometry, programme and materials. Specialists from various teams agree that the daylighting requirements set by certification systems are rather lax.

LEED, for example, has a single daylighting criterion for all spaces, whereas most spaces need unique daylighting criteria.

Practices therefore seek even higher goals in terms of design quality and innovation than certification systems propose. They

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∂ Green Specialist Journal for Sustainable Planning and Construction Published by: Institut für internationale Architektur-Dokumentation GmbH & Co. KG, Hackerbrücke 6, 80335 Munich, Germany Tel.: +49 (0)89-38 16 20-0 Fax: +49 (0)89-33 87 61 www.detail.de/english PO Box: Postfach 20 10 54, 80010 Munich, Germany

Page 42 Holiday house on Laesø island Tangborgvej 6 DK-9940 Læsø • Client: Realdania Byg, Copenhagen • Architects: Tegnestuen Vandkunsten, Copenhagen • Engineers: Moe, Århus • Life cycle analysis: Jan Schipull Kauchen, Copenhagen • Construction consultant: Anne Mette Manelius, Copenhagen • Main contractor, carpentry: Greenhouse, Kongerslev • Carpentry (frames for upholstered ceilings): Praktisk Service, Møn • Seaweed delivery: Ib Ungermand, Bogø; Jens Vedele, Møn • Seaweed pillow production and industrial knitting: Helle Raknes, Møn • Upholstery: Liebeck’s Traditionel Møbelpolstering, Frederiksberg • CNC cutting (for upholstery): FabLab Denmark, Næstved • Installation of ceiling elements: Michael Fischer, Frederikshavn • HVAC, plumbing and sewage: Øens VVS, Laesø • Electrical installations: Østerby El-service, Laesø • Excavations, foundation pillars, road construction: Carl Olsen, Laesø • Furniture: Genbyg, Copenhagen

Limited partner: ATEC Business Information GmbH General partner: Institut für internationale Architektur-Dokumentation Verwaltungs-GmbH, a 100 per cent subsidiary of ATEC Business Information GmbH. Publishing director: Meike Weber Editorial team: (address as above) Tel.: +49 (0)89-38 16 20-57 Email: redaktion@detail.de Christian Schittich (editor-in-chief, (V. i. S. d. P.), Sabine Drey, Andreas Gabriel, Frank Kaltenbach, Julia Liese, Michaela Linder, Thomas Madlener, Peter Popp (Online), Maria Remter, Jakob Schoof, Edith Walter, Heide Wessely Marion Griese, Emese M. Köszegi, Simon Kramer, Dejanira Ornelas Bitterer (drawings) Editorial team DETAIL transfer: Meike Weber (V. i. S. d. P.), Tim Westphal (manager), Patricia Beck, Zorica Funk, Katja Reich, Dijane Slavic, Cordula Vielhauer, Hildegard Wänger Tel.: +49 (0)89-38 16 20-0 English translations: Feargal Doyle, Sharon Heidenreich, Sean McLaughlin, Lance Phipps English copy-editing & proofreading: Anna Roos Production/DTP: Peter Gensmantel (manager).

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