MODULAR HOMES: WHY NOT SOONER?
The Challenges Associated with the UK’s Next Generation of Mass Housing
ARC556 DISSERTATION James Paul 180208265
Preface
ABSTRACT
Since the turn of the century, the UK has been struggling to cope with the creation of new homes for a rapidly increasing population, leading to a housing shortage, and ‘crisis’. Limited housing stock has been detrimental to the market, with home ownership often out of reach for first-time buyers, leading to homelessness, and the creation of ‘Generation Rent’. To combat this shortage, the modularisation of buildings is being touted as one solution. This idea has precedent in the UK, with examples dating back to the late 1940s - but in later years it fell out of favour. Now, with the shortfall in homes in England reaching over 4 million, and emergent technologies making off-site construction of these prefabricated modules more viable, the housing sector is expressing a renewed interest in this method of construction. This study examines the current literature on modular construction, and its historical use within the UK. From this, the issues expressed by other authors are assessed, with interviews from members of the UK construction industry allowing for detailed discussion of the key issues surrounding volumetric house building: site and transportation constraints; cost and economies of scale; and a construction industry that is resistant to change. From these issues, solutions are discussed as to how to alleviate their effects and include: the decentralisation of home-building to smaller ‘pop-up’ factories; the creation of a construction board that focuses on modular construction; and a public focus on the quality of factory-built housing.
III
Modular Homes: Why Not Sooner?
IV
Preface
0.0 CONTENTS
ABSTRACT
III
LIST OF FIGURES
VII
1.0 INTRODUCTION 1.1 UK Housing Crisis 1.2 Modern Methods of Construction: ‘Prefabrication’ vs. ‘Modular’ 2.0 CURRENT CONTEXT 2.1 Modular Construction Around the World 2.2 UK Prefabrication and Connotations 2.3 Module Types 2.4 Current Gaps 3.0 METHODOLOGY & METHODS Literature Review Interviews Results and Analysis Final Conclusions and Discussions 4.0 RESULTS & ANALYSIS Interviewees 4.1 Key Issue 1: Site and Transportation Constraints 4.2 Key Issue 2: Economies of Scale & Cost 4.3 Key Issue 3: A New Way of Working for the UK Construction Industry 4.4 Other issues
V
2 4 10 12 15 18 25
28 34 37 40
Modular Homes: Why Not Sooner?
5.0 CONCLUSIONS 5.1 Summary of findings 5.2 Further research 6.0 BIBLIOGRAPHY 6.1 Books / Journals 6.2 Web Resources 6.3 Misc. Resources 6.4 Figures 7.0 APPENDIX 7.1 Interview with Interviewee 1 transcript 7.2 Interview with Interviewee 2 transcript 7.3 Interview with Interviewee 3 transcript
46 47 49 51 54 54 57 64 69
VI
Preface
LIST OF FIGURES
Cover Image - Fab House INTRODUCTION Figure 1.1 - UK Housing Crisis Figure 1.2 - Estimated annual number of houses required for scenarios identified in the 2004 Barker Review and actual net additions to the housing stock, England Figure 1.3 - Ratio of median house price to median earnings, England Figure 1.4 - Prefabrication and it’s subcategories Figure 1.5 - levels of off-site building technology Figure 1.6 - Prefabricated homes built after WW2 in Norwich Figure 1.7, 1.8 - Modular housing scheme in Tower Hamlets by Waugh Thistleton Architects
CURRENT CONTEXT Figure 2.1- House by Urban Splash Figure 2.2 - Sweden’s BoKlok modular housing Figure 2.3 - Mansion House, Manchester Figure 2.4 - SHoP’s 461 Dean, Brooklyn Figure 2.5 - Murray’s Grove, London Figure 2.6 - What are the most significant barriers against the use of offsite MMC in the UK Figure 2.7 - Habitat 67, Montreal Figure 2.8 - Urban Rigger student housing, Copenhagen Figure 2.9 - Boxpark eatery, Shoreditch Figure 2.10 - Cancer centre Amsterdam
VII
1 3 4 5 5 6 6
10 11 11 11 13 14 16 17 17 17
Modular Homes: Why Not Sooner?
METHODOLOGY & METHODS Figure 3.1 – Methodology diagram
RESULTS & ANALYSIS Figure 4.1 – Interviewees Figure 4.2 – Issues outlined by Aitchison et al Figure 4.3, 4.4 - Urban Splash’s sites in Birmingham and Manchester Figure 4.5 - Precision Manufactured Living’s on-site factory at Borough Academy Figure 4.6 - Factory outreach Figure 4.7 - ‘Localised’ solution Figure 4.8 - How the Built InCommon system promotes a local ecology Figure 4.9 - Positives and negatives of nationalised vs. localised housebuilding Figure 4.10 - How the cycle of low demand and low orders stymies volumetric housebuilders Figure 4.11 - Homes for the North Group framework diagram Figure 4.12 - Current construction management structure, vs. Swan Housing’s system Figure 4.13, 4.14 - Comparisons between traditional and off-site construction processes Figure 4.15 - Responses from a 2014 survey of Japanese customers on their reasons for choosing a prefabricated home Figure 4.16-4.20 - Ilke Homes’ modular house types
CONCLUSIONS Figure 5.1 - Legal & General’s modular housing factory
26
27 27 29 30 31 32 33 34 35 37 38 39 40 42
45
VIII
Modular Homes: Why Not Sooner?
1.0 INTRODUCTION
1.1 Background - UK Housing Crisis
‘We are … very conscious that we have not built enough homes in this country year on year for many decades …’1 Brandon Lewis, 2016 ex-minister of state Described as ‘…one of the greatest barriers to progress in Britain today’2, the ‘UK Housing Crisis’ is the name given to the ongoing shortfall of housing stock in the UK. With the gap between new building stock and needed homes estimated at around 100,000 units annually3, and a total deficit of 4 million homes in England alone4, the housing market is struggling to keep up with demand. This housing shortage has had severe knock-on effects in the UK, including rapidly rising house prices5, a rise in homelessness, and the creation of ‘Generation Rent’6. Whilst this isn’t a new issue, with shortages of housing stock being lamented in The Times as early as the 1980s; ‘…a critical lack of [housing] supply unless large-scale building programmes are undertaken immediately…’7 the Housing Crisis is now at the forefront of British politics. The 2017 Conservative government highlighted it as one of their core issues, with a manifesto pledge to deliver their 2015 commitment of 1,000,000 homes by 2020, and another 500,000 by 2022.
Fig.1.1 - UK Housing Crisis
The reasons as to why this deficit exists are numerous, with government reports highlighting issues including insufficient planning, a lack of public sector housebuilding, and a slow delivery of homes by the large housebuilders. However, this report will focus on the lack of alternatives to traditional housebuilding within the UK. These ‘Modern Method[s] of Construction’ include off-site construction of housing ‘modules’ and have been touted as one solution to the housing crisis - providing an alternative to conventional housing built with bricks and mortar. Prefabrication in the UK isn’t a new concept, with the Emergency Factory Made Home programme of the 1940s producing over 150,000 temporary ‘prefab’ homes to replace those destroyed during WW2. So, with numerous new modular projects hitting the headlines in recent years8 9 10, why has it only just started to become popular? This study sets to look at the issues and challenges associated with modular homes and find out why they aren’t more prolific in the UK. 2
1.0 Introduction
340,000
320,000
300,000
NEW ESTIMATED HOUSING NEED 280,000
260,000
240,000
220,000 200,000
180,000
160,000 140,000
120,000
Fig.1.2 - Estimated annual number of houses required for scenarios identified in the 2004 Barker Review and actual net additions to the housing stock, England
3
‘Number of new homes required to annually improve the housing market’ (1.1% annual growth)
‘Number of new homes required to reduce the trend rate of house price growth from 2.7%’ (1.8% annual growth)
Government target (Sustainable Communities Plan) for 2006 - 2016
Net additions to housing stock
2018
2017
2016
2015
2014
2013
2012
2011
2010
2009
2008
2007
2006
100,000
Modular Homes: Why Not Sooner?
House Price : Wage Ratio
8
6
4
2
2015
2014
2013
2012
2011
2010
2009
2008
2007
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
0
Change in house price data used
Source: DCLG live table 578
Fig.1.3 - Ratio of median house price to median earnings, England
1.2 ‘Prefabrication’ vs. ‘Modular’
‘…to think of modular construction as a structural or architectural approach is to miss the point. It is a means of delivery…’11 Christopher Nash ‘Modern Methods of Construction’ (MMC) is a term introduced by the UK government in the early 2000’s to describe recent innovations in housebuilding such as offsite construction methods, which include prefabricated and modular elements. As modular construction is often considered a more specialised form of prefabricated construction, the two terms have considerable cross-over, with prefabrication in the construction sector referring to ‘…factory-made components or units that are transported and assembled on-site to form the complete building…’12, whereas modular systems are ‘…three dimensional or volumetric units that are generally fitted out in a factory and delivered to site as the main structural elements of the building’13. Essentially this means that whilst all modular buildings are prefabricated, not all prefabricated buildings are modular.
4
1.0 Introduction
PREFABRICATION
Modular Fig.1.4 - Modular systems are a sub-category of prefabrication, and volumetric a further subcategory
Volumetric
These modular systems can range in size from non-structural bathroom pods and precast stair and lift elements through to full building storeys, complete with walls, which can either be load-bearing or affixed to a structural framing system. This study aims to look at the latter, whereby a single module can make up an entire floor of a home, which is considered large-scale module building, and is referred to as ‘volumetric construction’. Lawson et al. consider these large-scale modules to be in levels 3 and 4 of offsite construction, where more than 70% of the overall build cost comes from prefabricated components.
Level
Components
Description of Technology
0
Materials
Basic materials for site-intensive construction, e.g. concrete, brickwork
1
Components
Manufactured components that are used as part of site-intensive building processes
2
Elemental / Planar Systems
Linear or 2D components in the form of assemblies of structural frames and wall panels
3
Volumetric Systems
3D components in the form of modules used to create major parts of the building, which may be combined with elemental systems
4
Complete Building Systems
Complete building systems, which comprise modular components, and are essentially fully finished before delivery to the site
Fig.1.5 - Levels of Off-Site Building Technology
5
Modular Homes: Why Not Sooner?
Fig.1.6 - Prefabricated homes built after WW2 in Norwich
Fig.1.7, 1.8 - Modular housing in Tower Hamlets by Waugh Thistleton
6
1.0 Introduction
REFERENCES
Lewis, B. & Hinds, D., 2016. Inquiry on the Economics of the UK Housing Market [Interview] (22 March 2016). 2 Department for Communities and Local Government, 2017. Fixing Our Broken Housing Market. London: Department for Communities and Local Government, pg5 3 Wilson, W. & Barton, C., 2018. Tackling the Under-Supply of Housing in England. [ebook] Available at: http://researchbriefings.files.parliament.uk/documents/CBP-7671/CBP-7671.pdf pg3 [Accessed 3 January 2019]. 4 Stephens, M. et al., 2018. 2018 UK Housing Review. Coventry: Chartered Institute of Housing. pg7 5 Department for Communities and Local Government, 2017. Fixing Our Broken Housing Market. pg10 6 The term given to potential first-time buyers who, because of high house prices, are stuck renting accommodation with little chance of becoming homeowners themselves 7 Select Committee on Economic Affairs, 2016. Building More Homes. [ebook] Available at: https://publications.parliament.uk/pa/ld201617/ldselect/ldeconaf/20/20.pdf pg10 [Accessed 22 March 2019]. 8 Hurst, W. & Waite, R., 2019. Urban Splash Team Set to Build Huge Modular Housing Scheme for New Town. [Online] Available at: https://www.architectsjournal.co.uk/news/urban-splash-team-set-to-build-huge-modularhousing-scheme-for-new-town/10039691.article [Accessed 3 January 2019]. 9 Pitcher, G., 2019. ShedKM Reveals Plans for Modular Manchester Housing. [Online] Available at: https://www.architectsjournal.co.uk/news/shedkm-reveals-plans-for-modular-manchesterhousing/10040473.article [Accessed 5 March 2019]. 1
7
Modular Homes: Why Not Sooner?
Wilson, R., 2018. ShedKM Completes Modular Townhouses in North Shields for Urban Splash. [Online] Available at: https://www.architectsjournal.co.uk/buildings/shedkm-completes-modular-townhouses-innorth-shields-for-urban-splash/10019669.article [Accessed 3 January 2019]. 11 Lawson, M., Ogden, R. & Goodier, C., 2014. Design in Modular Construction. Boca Raton: CRC Press., pgxiii 12 Wikipedia, 2019. Prefabricated Building. [Online] Available at: https://en.wikipedia.org/wiki/Prefabricated_building [Accessed 25 March 2019]. 13 Lawson, M., Ogden, R. & Goodier, C., 2014. Design in Modular Construction. pg1
10
8
Modular Homes: Why Not Sooner?
2.0 CURRENT CONTEXT
2.1 Modular Construction Around the World
Initial research regarding modular construction looked at international trends, and how the industry differed around the world. Sourcing information specifically on modular construction proved challenging due to the lack of a singular definition of ‘Prefabrication’ - an issue discussed by Aitchison et al., who state that ‘The lack of consensus around terminology and definition has greatly impaired the ability to collect accurate data…’1 of how prevalent prefabricated construction is in other country’s building sectors. In Hong Kong and China, Ferdous et al. looked at the challenges facing modular design2. Whilst China’s highly industrialised economy is considerably different to the UK’s predominantly service-based economy, the issues surrounding prefabrication are similar. Even though the move to prefabrication for China should be an easy switch, the report cites high upfront costs as the primary stumbling block, something that is seconded by reports from the UK3 4, with parliamentary sources here showing a 7-10% rise in construction cost when compared to conventional methods5. Whilst these high costs might have been an issue when that document was originally written, they seem to be less of a barrier today, or the benefits now outweigh the costs, as both Laing O’Rourke and Legal & General, two prominent UK housebuilders, have invested significant funds in modular factories in recent years, at £104million and £55million respectively6 7.
Fig.2.1 - House by Urban Splash
Ferdous et al. found that a lack of design guidelines was a problem in several countries; for instance the Australian Centre for Construction Innovation stated that a lack of coherent regulations was a major barrier to Off-Site Manufacture (OSM) in 20078. In the UK, this has been a similar issue until recently, with a joint venture between Swan Housing and Waugh Thistleton Architects leading to the creation of their ‘Modular Design Guide’9, which focuses on volumetric housing, and what needs to be considered and addressed at each stage. However, this guide is London-centric in terms of transport considerations and building regulations, due to Swan Housing’s modular factory being located in Essex, and focuses solely on volumetric construction with Cross Laminated Timber (CLT), due to how Swan construct their modular homes. Although, with CLT being a potential replacement for concrete within the housing industry, 10
2.0 Current Context
Fig.2.2 - Sweden's BoKlok modular housing
Fig.2.3 - Mansion House, Manchester
11
Fig.2.4 - SHoP's 461 Dean, Brooklyn
Modular Homes: Why Not Sooner?
similarities can be drawn between module construction from CLT panels and panellised concrete. Another guide by Lawson et al. provides a broad overview of modular construction whilst also speaking about the benefits of OSM10. These benefits include, but aren’t limited to: shorter build times; safer construction due to less people on site; lower transport costs; superior quality (Interviews with modular builders by London Assembly found that modules have thermal properties close to Passivhaus standard11 12) and less wastage, with modular building manufacturer Yorkon stating a 90% reduction in waste compared to typical on-site construction13. Whilst both guides are useful for understanding how modular systems work and constructed, neither discuss why volumetric construction isn’t prevalent in the UK housing industry. Japan’s highly mature modular housing industry is highlighted by both Lawson et al. and Aitchison et al. as an exemplar industry, with both sources providing in-depth analysis. Established in the 1970s, the industry has been able to develop, and at its peak was selling 170,000 homes a year, with a typical construction cycle from installation to finishing lasting 6 days. These houses are based around a high degree of user choice for layout and fittings, a key selling point that is now being used by Urban Splash as a marketing tool for their ‘House by Urban Splash’ modular homes, to entice UK homeowners14. In the United States, the modular homes industry developed around its well-established mobile homes industry in which, as of 2013, 6% of the US population lived15 16. However, their prefabricated housing industry has had its fair share of false starts, with a prominent example being the Packaged House from General Panel Company, founded by Bauhaus pioneers Walter Gropius and Konrad Wachsmann. Imperiale looks at the issues that plagued the Packaged House through the lens of System Theory17 18. Even with another method of critique being applied, and that the Packaged House was a panellised system, the issues discussed remain relevant to modern day volumetric construction, the most notable being that of buildability and standardisation. As the house was designed around plywood panels that were 3’4” wide by 10’ high, compared to the industry standard of 4’ by 8’, there were high start-up costs from cutting the panels down to size, resulting in homes that were more expensive compared to traditional options, which led to the company going bust less than a decade after being set up. Recent attempts at volumetric housing in the US have been more successful, with SHoP’s 32 storey 461 Dean in Brooklyn one of the tallest volumetric buildings in the world.
2.2 UK Prefabrication and Connotations
In the UK, the flexibility of prefabricated homes was an issue even in the 1960’s, and the connotations of the name ‘Prefab’ bring back memories of post-war housing for the general public, which was ‘…mired in the low-quality, poor-design reputation’19. This perception still affects MMC in the UK today20, a point seconded by Edge et al. in their report about overcoming client resistance to prefabrication21. However, 12
2.0 Current Context
Fig.2.5 - Murray Grove, London
these connotations could be due to post-war prefab housing often outliving its intended lifespan. As these houses were designed as temporary residences for 10 years, instead of the 50 years some were in use, their elongated lifespan highlights that they were built to a higher standard than given credit for. The negativity around prefabricated homes was also related to a supposed stigma of rented housing in the UK, as home ownership was seen as a privilege, something briefly mentioned by Knaack et al.22 Pan et al. contradicts these negative connotations being directly related to prefab homes, reporting that the end user doesn’t really care how houses are built, and they instead place priority on location and price23. Whilst prefabricated buildings in the UK have been around for over half a century, modular construction as defined in section 1.2 is a much newer industry, with the first scheme in the UK to gain public attention being Murray Grove by Cartwright Pickard, constructed in 1999. Because of this, literature going into depth about local modern modular buildings is hard to come by, with Lawson et al. the primary resource for UK based examples. Even with this guide, the general lack of historical knowledge of prefabricated homes, both in this country and worldwide, is a concern raised by Aitchison et al., saying ‘…historical understanding of prefabricated housing and the challenges it has faced evidences a kind of amnesia’24.
13
Modular Homes: Why Not Sooner?
Complex interfacing between systems
29%
Unable to freeze the design early on
29%
Site constraints and logistics
7% 68%
Higher capital cost Difficult to achieve economies of scale
43%
Risk averse culture
7%
Client scepticism 4% Attitudinal barriers due to historic failures
11% 14%
Reluctance to innovation Skills shortages
11%
Fragmented industry structure
11%
Nature of the UK planning system
25% 11%
Manufacturing capacity
14%
Lack of previous experience Dominant importance of land acquisition in house building business
11% 0%
20%
40% Percentage of Respondents
60%
80%
Fig.2.6 - Pan et al.’s responses as to what housebuilders considered the most significant barriers against the use of offsite MMC in the UK
Figure 3 Most significant barriers against the use of offsite MMC in the industry
14
2.0 Current Context
Although attitudes towards MMC have changed significantly in the UK since they were discussed by Pan et al. in their 2005 report into the perception of offsite construction from housebuilders25, its contents were still incredibly relevant, highlighting what were considered the issues and challenges at the time. This also served as a basis for the later sections of this report, to see if these issues and barriers were still prevalent today, or whether attitudes had changed significantly in the past 14 years. At the time, offsite construction made up just 2.1% of the total construction industry in the UK. Whilst this had risen to 7% by 201726, the uptake has been slow. Whether this is due to some of the previously discussed issues surrounding modular construction, or outside factors such as the 2007 global financial crisis, is unknown.
2.3 Module Types
Within the modular housing industry, modules types can be separated into 3 key materials: Concrete, Steel and Timber. Each material has its own strengths and weaknesses and are used in differing circumstances. For instance, concrete is often used for lift shafts modules and bathroom pods, due to its high compressive strength, and resistance to water damage respectively.
Concrete
Due to its high weight when compared with steel and timber modules of a similar size, modular construction using concrete is usually restricted to areas where the necessary volume can be achieved, with Lawson et al. citing hotels, prisons, and schools as the most common applications27. The majority of modular construction with concrete today consists of panellised construction, which isn’t the focus of this study. With concrete being seen as an innovative material at the start of the 20th century, most volumetric modular examples are from the early to mid-1900s. One example is Thomas Edison’s single pour house, which he marketed as being ‘almost indestructible’, and cheaper to beautify than standard housing28. However the expensive formwork, at about $175,000, and that it would still have to be poured on-site, meant it was limited to a few prototypes before being scrapped. Whilst being far removed from modern prefabrication techniques, the industry does still share a few similarities with the ideas Edison discussed, and modern-day advancements in formwork and concrete might increase the validity of this option today. Another example that is more relevant to current modular housebuilding is Habitat 67 in Montreal, by Safdie Architects. Similar to current OSM methods in the UK, Habitat 67 was an exploration of using volumetric construction to lower housing costs, built for the Montreal World Fair in 1967. The complex highlights the issues surrounding economies of scale in modular construction, as Habitat 67 was originally conceived as 1000 modular housing units. However, the Canadian government cut the scheme to just 158 residential units – this reduction, coupled with the relative complexity of the design, meant costs were considerably
15
Modular Homes: Why Not Sooner?
Fig.2.7 - Habitat 67, Montreal
higher than anticipated, at approximately C$140,000 per unit29 (roughly £630,000 today). Generalova et al. highlights another issue with concrete module construction that was discussed earlier – negative perceptions. Whilst looking at 3D block house construction in Russia, the benefits of the system mirror those highlighted already by Lawson et al., namely that a building can be constructed quickly and to a higher quality than on-site. However, this construction method was introduced in 1974, and has barely changed visually since then, resulting in bland high-rises that are reminiscent of residential blocks built in the former USSR30. Steel
One benefit of constructing modules from steel is that they’re 100% recyclable, helping to combat the 200 million tons of concrete waste in Europe annually31, as demolished concrete structures can only make up a part of new aggregate. However, the option to reuse steel is even better, with Vijayalaxmi stating that the process of reusing the 3.63 tonnes of steel needed to construct a shipping container requires about 400kWh of electrical energy – 5% of the energy required to melt it down32. With steel, a lot of related modular construction is based around the reuse of shipping containers. Due to their unified size around the world, and often being transported by sea, road, and rail, this reuse begins to negate some of the commonly cited issues of modular home construction. In recent years, designs based around steel containers have begun to become prevalent, whether as ‘pop-up’ eateries, floating student housing, or even as a temporary institute for a hospital. However, these designs are inherently temporal and aren’t necessarily suitable styles for long-term house construction. In the context of housebuilding, Sun et al. looked at utilising shipping container modules in northern China, where long winters hamper the construction cycle33. Modular construction is chosen to shorten the on-site assembly time, resulting in a construction period 1/3rd the length of an equivalent concrete 16
2.0 Current Context
Fig.2.8 - Urban Rigger student housing, Copenhagen
Fig.2.9 - Boxpark Eatery, Shoreditch
17
Fig.2.10 - Cancer Centre Amsterdam
Modular Homes: Why Not Sooner?
build, but with a 40% increase in its useful lifespan. Moreover, shipping containers were chosen as they’re already known for their high durability, and high structural strength when stacked - being able to support 30 metric tons when in their original configuration34. Although, whilst the structural strength of a standard shipping container is known, the issue cited by Giriunas et al. is the lack of guidelines for safely modifying shipping containers to create suitable housing modules, often leading to additional reinforcement that might not be necessary35, and relating back to the wider issue of guidelines not keeping up with new construction methods. Timber
As a ‘sustainable’ alternative to concrete, timber framed modules are becoming one of the key systems for volumetric construction. These modules are constructed from CLT panels, where layers of lumber are glued together in perpendicular layers; similar to plywood, but at a greater thickness than regular ply. This creates parts that have the same strength as similar concrete structures, but for 1/5th of the weight36. The use of wood over concrete also allows the building to sequester carbon37. For instance, Waugh Thistleton’s Stadthaus project in Murray Grove ‘stores’ 181 tonnes of CO2 and stopped the release of an additional 125 tonnes of C02, due to the loss of concrete production emissions38. Whilst being touted as more environmentally friendly than concrete when produced, the UK doesn’t currently have any CLT production facilities, with most being imported from Austria, increasing carbon emissions through transportation. Sustainable architecture that uses timber prefab modules is also discussed by Emmanuel Rey, who talks of a building concept based around 22m2 wooden prefabricated modules, created to increase housing density in Switzerland, as well as improve energy efficiency in homes39. In the UK, five of these standardised modules would create a home larger than the current average of 93.6m2 40, so would be a viable option for house construction. As well as it’s structural properties, timber as a building material for modules is favoured in Scandinavian countries due to its similarity to traditional building techniques. For instance, BoKlok41 – a collaboration between Ikea and Skanska, has built roughly 11,000 homes across Sweden, Norway and Finland, since being founded in 1997. These homes range from a traditional Swedish vernacular house, through to terraced housing, where residents can choose the number of bedrooms, roof type, or external finishes. Whilst now being redeployed in the UK, an earlier pilot scheme in the mid-2000s was less successful, with issues arising due to the differences between Scandinavian and UK lifestyles, the use of timber frames over brick-and-block construction, and the global financial crisis42.
2.4 Current Gaps
From this review, the author found that the majority of research has been about the benefits of modular construction compared to traditional methods, which is likely due to it being an emerging market, resulting in a bias to try and increase its uptake. With the exception of Pan et al., few have researched how any of the 18
2.0 Current Context
issues have hindered it’s use within the UK housing market. Also, the current research doesn’t specifically look at volumetric construction but instead focuses on the wider term of prefabrication, reinforcing the issue surrounding the definition of ‘modular’ construction, something defined earlier in this report. To build upon current research, this report will qualitatively look at issues described by previous authors, as well as those discussed through interviews with members of the UK housing industry. This will allow for a nuanced, critical understanding of these issues, and how they’ve played a role in the slow uptake of modular housing. From this, solutions will be proposed and discussed to assess their suitability.
19
Modular Homes: Why Not Sooner?
20
2.0 Current Context
REFERENCES
Aitchison, M. et al., 2018. Prefab Housing and the Future of Building: Product to Process. London: Lund Humphries Publishers. pg62 2 Ferdous, W. et al., 2019. New Advancements, Challenges and Opportunities of Multi-Storey Modular Buildings – A State-of-the-Art Review. Engineering Structures, Volume 183, pg883-893. 3 London Assembly, 2017. Designed, Sealed, Delivered: The Contribution of Offsite Manufactured Homes to Solving London’s Housing Crisis. [ebook] Available at: https://www.london.gov.uk/sites/default/files/london_assembly_osm_report_0817.pdf [Accessed 3 January 2019]. 4 Pinsett Masons, 2017. Modular Construction in UK Housing: An Overview of the Market, the Players and the Issues. [Online] Available at: http://constructingexcellence.org.uk/wp-content/uploads/2017/02/graham-robinsonpinsent-masons-14022017.pdf [Accessed 3 January 2019]. 5 Parliamentary Office of Science and Technology, 2003. Modern Methods of House Building. London: Parliamentary Office of Science and Technology. 6 Pinsett Masons, 2017. Modular Construction in UK Housing: An Overview of the Market, the Players and the Issues. 7 The Guardian, 2017. Prefab Sprout: Off-the-peg Homes Bid to Ease UK Housing Crisis. [Online] Available at: https://www.theguardian.com/money/2017/jul/15/prefab-sprout-off-the-peg-homes-bidto-ease-uk-housing-crisis [Accessed 12 March 2019]. 8 Cooperative Research Centre for Construction Innovation, 2007. Off-Site Manufacture in Australia: Current State and Future Directions. Brisbane: Cooperative Research Centre for Construction Innovation. 9 Waugh Thistleton Architects, 2019. Nu Build Modular Design Guide. London: Swan Housing Association. 10 Lawson, M., Ogden, R. & Goodier, C., 2014. Design in Modular Construction. 1
21
Modular Homes: Why Not Sooner?
London Assembly, 2017. Designed, Sealed, Delivered: The Contribution of Offsite Manufactured Homes to Solving London’s Housing Crisis. pg22 12 Passivhaus is an international energy performance standard designed to dramatically reduce the requirement for space heating and cooling, without losing high indoor comfort. 13 Yorkon, 2016. The Advantages of a Modular Building. [Online] Available at: https://www.yorkon.co.uk/news-and-views/advantages-modular-building/ [Accessed 16 March 2019]. 14 Urban Splash, 2019. Welcome to House by Urban Splash. [Online] Available at: https://www.housebyurbansplash.co.uk/ [Accessed 3 January 2019]. 15 Geoghegan, T., 2013. Why Do So Many Americans Live in Mobile Homes?. [Online] Available at: https://www.bbc.co.uk/news/magazine-24135022 [Accessed 7 June 2019]. 16 United States Census Bureau, 2019. U.S. and World Population Clock. [Online] Available at: https://www.census.gov/popclock/ [Accessed 7 June 2019]. 17 Imperiale, A., 2012. An American Wartime Dream: The Packaged House System of Konrad Wachsmann and Walter Gropius. Philadelphia, ACSA. 18 Systems Theory is the interdisciplinary study of systems, or how parts work together 19 Aitchison, M. et al., 2018. Prefab Housing and the Future of Building: Product to Process. pg88 20 Parliamentary Office of Science and Technology, 2003. Modern Methods of House Building. 21 Edge, M. et al., 2002. Overcoming Client and Market Resistance to Prefabrication and Standardisation in Housing, Aberdeen: Robert Gordon University. 22 Knaack, U., Chung-Klatte, S. & Hasselbach, R., 2012. Prefabricated Systems: Principles of Construction. Basel: Birkhauser. 23 Pan, W., Gibb, A. G. F. & Dainty, A. R. J., 2007. Perspectives of UK Housebuilders on the Use of Offsite Modern Methods of Construction. Construction Management and Economics, 25(2), pg183-194 24 Aitchison, M. et al., 2018. Prefab Housing and the Future of Building: Product to Process. pg23 25 Pan, W., Gibb, A. G. F. & Dainty, A. R. J., 2007. Perspectives of UK Housebuilders on the Use of Offsite Modern Methods of Construction. 26 Oakley, M., 2017. The Value of Off-Site Construction to UK Productivity and Growth, London: WPI Economics. 27 Lawson, M., Ogden, R. & Goodier, C., 2014. Design in Modular Construction. pg42 11
22
2.0 Current Context
Edison, T., 1917. Process of Constructing Concrete Buildings. United States of America, Patent No. 1,219,272. 29 Wikipedia, 2019. Habitat 67. [Online] Available at: https://en.wikipedia.org/wiki/Habitat_67 [Accessed 20 July 2019]. 30 Generalova, E. M., Generalov, V. P. & Kuznetsova, A. A., 2016. Modular Buildings in Modern Construction. Procedia Engineering, Volume 153, pg167-172. 31 Tabsh, S. W. & Abdelfatah, A. S., 2009. Influence of Recycled Concrete Aggregates on the Strength Properties of Concrete. Construction and Building Materials, 23(2), pg1163-1167. 32 Vijayalaxmi, J., 2010. Towards Sustainable Architecture - A Case With Greentainer. Local Environment The International Journal of Justice and Sustainability, 15(3), pg245-259. 33 Sun, Z., Mei, H. & Ni, R., 2017. Overview of Modular Design Strategy of the Shipping Container Architecture in Cold Regions. IOP Conference Series: Earth and Environmental Science, 63(1). 34 Grębowski, K. & Kałdunek, D., 2017. Using Container Structures in Architecture and Urban Design. IOP Conference Series: Materials Science and Engineering, Volume 245. 35 Giriunas, K., Sezen, H. & Dupaix, R. B., 2012. Evaluation, Modeling and Analysis of Shipping Container Building Structures. Engineering Structures, Volume 43, pg48-57. 36 Waugh, A., 2019. Wood In Architecture. Sheffield. [Lecture] (29th March 2019) 37 Wood acts as a carbon store by absorbing CO2 during its lifespan, and doesn't release this once felled, unless it's burnt 38 Larsson, M., Kaiser, A. & Girhammar, U. A., 2012. Multi-Storey Modular Manoeuvres - Innovative Architectural Stacking Methodology Based on Three Swedish Timber Building Systems. Auckland, World Conference on Timber Engineering. 39 Rey, E., 2012. Swisswoodhouse, an Innovative Concept for Sustainable Modular Housing. Lima, Proceedings of PLEA 2012, 28th International Conference on Passive and Low Energy Architecture, Lima, Peru, 2012. 40 ICE, 2018. Minimum Space Standards. [Online] Available at: https://www.designingbuildings.co.uk/wiki/Minimum_space_standards [Accessed 20 July 2019]. 41 BoKlok, 2019. About Us. [Online] Available at: https://www.boklok.com/about-us/ [Accessed 7 June 2019]. 28
23
Modular Homes: Why Not Sooner?
The Independent, 2009. Ikea Homes Development Falls Flat. [Online] Available at: https://www.independent.co.uk/property/house-and-home/ikea-homes-development-fallsflat-1501231.html [Accessed 13 September 2019]. 42
24
3.0 Methodology & Methods
3.0 METHODOLOGY & METHODS
Current Context
The critical review and analysis of current works, and the current state of the modular construction industry gives the author sufficient knowledge to make informed decisions in later sections of the report. It also highlights any research gaps which this study can ameliorate.
Interviews
With research into modular construction providing a suitable basis for further discussion, the issues discussed by Aitchison et al. and Pan et al. are utilised to create the main discussion points in the interviews. These interviews are undertaken with those currently in the UK housing market, with some that have completed modular schemes, and others that haven’t. These interviews create a clearer picture of where the key issues lie with modular construction and drives the discussion in the next section.
Results and Analysis
By combining the original research and interview data, qualitative analysis of this data can occur, which highlights the key issues associated with volumetric construction, and where the similarities are with previous sources. These key issues are then discussed further, with potential solutions from the author’s own ideas and other sources analysed.
Final Conclusions and Discussions
With a critical review of all the data from the report completed, final discussions about the challenges faced by modular housing in the UK can occur, with the conclusion providing a summary of the findings of the report. From this summary, the direction of where further subject research might lead can be ascertained.
25
Modular Homes: Why Not Sooner?
AUTHOR
2.0 Current Context
Interview (Via Skype / Phone)
DATA
DATA Data Collated
INTERVIEWEES
Follow-up Questions (Via Email)
DATA
4.0 Results & Analysis
5.0 Conclusions
Fig.3.1 - Methodology Diagram
26
4.0 Results & Analysis
Interviewee 1 Works for a housing association that have been piloting modular schemes, but haven’t built any volumetric homes yet
Interviewee 2 An architect who worked on a volumetric scheme that the contractor ended up building traditionally
Interviewee 3 Has worked on Gateshead Innovation Village - a test housing development utilising multiple volumetric housing suppliers
Fig.4.1 - To try and cover multiple areas of the UK housing market, interviews were undertaken with participants from a range of professions
Professions and Disciplines
Open vs. Closed System and IP
Regulation and Planning, Site and Location
Cost
Change Management and the Construction Industry
Partial Solutions
TECHNOLOGY
Standardisation vs. Customisation
Prefab Definition is Confusing
PERCEPTION
Analogies With Other Industrial Sectors
Innovation vs. Invention
Imminent Revolution
Technology and Progress
Means and Ends
MANAGEMENT
SYSTEM
‘Loose Fit’ and ‘Best Practice’
Fluctuations in the Housing Market and Scaling
Reputation
Finance
ECONOMIC Fig.4.2 - Issues outlined by Aitchison et al.
27
Modular Homes: Why Not Sooner?
4.0 RESULTS & ANALYSIS
To ensure the interviews were open-ended, whilst also covering the multitude of challenges that UK modular housing faces, the key problems highlighted by Aitchison et al., and Pan et al. were used as guidelines to inform the interview questions. The relevance of each issue to volumetric housing was assessed, and then compressed into key headings that facilitated discussion. From these headings, the interview structure could be formed to ascertain why the UK housing industry hasn’t embraced volumetric construction sooner. The key issues that were discussed through the course of the interviews are analysed in full below, with solutions proposed to combat these issues and help increase the use of volumetric construction in the UK housing industry.
4.1 Key Issue 1: Site and Transportation Constraints (SYSTEM)
‘The optimal dimensions of a module are determined by the size of the lorry and the restrictions associated with the route to the site, such as road widths and obstructions.’1 Nu Build Design Guide One of the key issues apparent throughout the interviews was related to site. In the context of Yorkshire, Interviewee 1 noted that the majority of their sites are sloped, meaning they weren’t immediately suited to volumetric construction, which limited testing sites. Even with panellised systems, the sites used for their pilot schemes resulted in considerable additional costs going into ground works and site regrading. In their case this doubled and tripled the overall unit cost, compared to the price of the system’s superstructure. Urban Splash’s way of circumventing this issue has been to build their homes on large expanses of relatively flat land, with their New Islington scheme in Manchester and the planned Port Loop development in Birmingham both utilising disused dockland sites. Whilst this is an obvious option for new developments, this isn’t viable for new homes on infill sites, which Interviewee 1 and 3 often construct. Ilke Homes notes the issue surrounding sites within their guide to volumetric construction, stating it 28
4.0 Results & Analysis
Fig.4.3, 4.4 - Urban Splash's sites in Birmingham and Manchester - situated across large flat areas of land, making them suitable for volumetric housing
shouldn’t be used ‘…for challenging site topographies, particularly heavily sloping sites…’2. In a similar vein, Interviewee 2 also raised issues relating to site. Due to the development being situated in a built-up area, it would have been difficult to crane the bathroom pods in around the rest of the structure when the design switched from a fully volumetric system. As well as this, both Interviewee 1 and 3 cited the size constraints of modules due to transport limitations as another major barrier to use. Interviewee 3 discussed this more in depth, with accessibility to ‘…certain 29
Modular Homes: Why Not Sooner?
sites that are up very little country roads, or particularly tight…volumetric doesn’t work…’3 and was one reason why they preferred panellised construction, which doesn’t have this issue. Long-distance module transportation is also tied to the next issue, which analyses economies of scale. In the current market, large-scale modular factories are required to bring down the cost of the units, so there’s only a few. As most of these factories have a relatively small outreach due to the cost of transporting modules vast distances, there is often a lack of overlapping coverage for housebuilding sites, limiting the options for volumetric construction to one supplier. Urban Splash is the outlier for this case, which is likely due to its strong financial backing, and its unique position as a supplier / developer creating a certainty of orders. For the other suppliers, this issue may change as they become more established. One way to combat the transportation issues can be found in Irena Bauman’s Built InCommon business model and MassBespoke system4. Built InCommon ships the tools required to make the panels used in the MassBespoke system in two containers, which can be placed within a development, localising construction and taking control away from the large housebuilders. In the context of modular housing, the superstructure would arrive as panels to a temporary factory either on-site or nearby, where the modules would be constructed with the rigour and quality found in OSM, and then transported the final distance to site for assembly. The downside to this is the increased number of vehicles to site, reducing one of the primary benefits of volumetric construction, but would remove the issue around transport limitations and size constraints, which is discussed later. Precision Manufactured Living created a similar delivery method when constructing a temporary school for Borough Academy, using a ‘pop-up’ factory on site to construct the modules, before moving them into place. Such a system could be transferred to the housebuilding market for medium to large scale developments, where it’s most economically viable.
Fig.4.5 - Precision Manufactured Living's on-site factory at Borough Academy
30
4.0 Results & Analysis
Fig.4.6 - Factory outreach
01 Miles 07 80
151 Mil es
Urban Splash 01. Smith’s Dock, North Shields 02. New Islington, Manchester 03. Wirral Waters, Wirral 04. Port Loop, Birmingham Walsall Waterfront, Walsall 05. Inholm, Northstowe 06. Campbell Park, Milton Keynes
Ilke Homes
Ilke Homes
03
08 02
09
07. Gateshead Innovation Village, Gateshead 08. Little Lever, Bolton 09. Dominion, Doncaster 10. Chase Farm, Gedling
121 Mi les
Urban Splash 10
Nu Build (Swan Housing) 04 05
Vison Modular 13. Greenford Green, Ealing 14. Chapter, Islington 15. Chapter, Lewisham 16. Canterbury Student Manor, Canterbury
06
Vision Modular 3
11. Beechwood West, Basildon 12. Watts Grove, Tower Hamlets
13 14 12 15
31
iles 1M 11
Nu Build
16
Modular Homes: Why Not Sooner?
Fig.4.7 - 'Localised' solution - combining the benefits of panelised and volumetric prefabrication techniques
01. Large scale factories produce / route necessary panels
02. Panels transported to on-site factory
03. Modules constructed in temporary factory
04. Modules transported for final assembly 32
4.0 Results & Analysis
Underutilised assets of land and buildings
Users Funders
Developers Community Builders
INTEGRATED SUPPLY CHAIN
Underutilised skills
Makers
PLACE Underutilised social capital
Suppliers
Built InCommon LOCAL ECOLOGY
The role of professionals and specialists
LEARNING & TEACHING
Governance
CIRCULAR ECONOMY
The role of tacit knowledge
Procurement Supply of land Future technology Web based platform
Knowledge transfer
PRODUCTION OF BUILDINGS Mass production / bespoke production
33
The role of educators
Collaborative production
Fig.4.8 - How the Built InCommon system promotes a local ecology
Modular Homes: Why Not Sooner?
NATIONALISED + High, centralised volume + Lower capital cost of module + Less transportation vehicles
Fig.4.9 - Positives and negatives of nationalised vs. localised housebuilding
4.2 Key Issue 2: Economies of Scale & Cost (ECONOMIC)
- Rigid capacity - Large orders required - More generic modules - High setup cost
LOCALISED + Flexible capacity + More bespoke modules + Can use existing factories + High, decentralised volume - More transportation vehicles - Higher capital cost of module
‘The true efficiencies of offsite volumetric manufacturing currently kick in at approximately 30 units of each housetype [sic]’5 Ilke Homes The second key issue that came up was the relative cost of volumetric construction compared to traditional bricks and mortar. For Interviewee 1, they were currently pursuing panellised construction, and were waiting to do a volumetric test pilot ‘…when it becomes affordable…’6. Whilst Interviewee 3 had completed several volumetric test homes, they shared similar sentiments, with their modular houses in the Gateshead Innovation Village being about 20 – 25% more expensive to construct than traditional homes. However, they also stated that Gateshead is considered one of the cheapest places in the country to build homes traditionally, and that the given cost differential would be marginal in the south of England. On top of this, with Ilke Homes looking to market their modular superstructure at between £65,000 £79,0007, this will likely put volumetric construction on par with traditionally built homes in the next few years8. Interviewee 2 stated that their cost issues came not only from the cost of the system, but also because the modular supplier was relatively new to the market, resulting in additional costs due to the 34
4.0 Results & Analysis
increased risk. Moreover, further cost savings were presented to the client by the contractor if the scheme switched to traditional construction, as they could use the same sub-contractors throughout, which led to the removal of all the modular systems from the building. Although Interviewee 1 found the panellised systems they tested to be cheaper than volumetric, other sources show this might be a localised issue, with a study in Canada finding a volumetric system to be cheaper than panellised when both systems were used to create a standardised house9. However, as this study was only related to superstructure, other factors in the UK might play a part as to why volumetric is more expensive, such as the aforementioned issues around site and transportation. Site differences were another factor for the cost discrepancies with Interviewee 1’s various test schemes, making a normalised comparison more difficult.
Small factory due to high capital costs
Factory can’t expand due to lack of orders
£££
Modules are expensive due to factory’s low output
£££
+
Fig.4.10 - How the cycle of low demand and low orders stymies volumetric housebuilders
35
High module costs deter developers, so orders are low
Modular Homes: Why Not Sooner?
As well as the high capital cost of the superstructure, more cost issues arise from the required economies of scale. Due to modular housing in the UK comprising less than 10% of all new homes constructed in 201710, there has been insufficient demand for volumetric construction; a system that requires significant orders to lower costs. This creates a cycle of low demand and insufficient supply, resulting in modular housing being unable to increase its market share. Interviewee 1 believed this lack of supply was another factor in why volumetric was expensive, as when they looked at SIG’s modular system before Urban Splash bought it, the superstructure was roughly double the cost of any others they were looking at ‘…because they weren’t making enough of them…’11 12. This ‘Catch 22’ of needing a high-volume system established before orders are made was discussed in Australia as early as 2007, with one of the key barriers for implementing fully modular systems being the volume necessary to make it competitive13. These capacity problems in the UK market were further discussed with Interviewee 3, who stated that even if they wanted to increase the percentage of volumetric homes they built, there simply wasn’t the capacity in the system to achieve this. They also cited that the immaturities of the system resulted in a lack of efficiency, with modular companies not able to appropriately cost the superstructure yet; ‘…they’re buying their materials in small volumes, they haven’t got their manufacturing processes ironed out, or really efficiently planned…’14 which was increasing the cost for homebuilders. Interviewee 2’s issues with cost also related to the wider scale issue, as the building they were constructing was a bespoke three storey structure. At the time of construction in 2013/14 this structure wouldn’t have been at a scale to be economically viable - an issue that still arose when using bathroom pods. The wider cost margins at the time outweighed the benefits of using a volumetric system, so it wasn’t used for the final build. With new factories being built by seasoned homebuilders such as Legal & General, these costs are likely to be reduced as the capacity to complete large orders increases. However, this creates another problem of supply predictability; in the UK’s often volatile housing market, why should companies take the financial risk of building modular factories if they’re unsure that they’ll have a sustainable influx of orders? One solution to alleviate this issue would be the creation of a procurement framework with other developers to maintain a predictable supply. Interviewee 1 was instigating a similar method with ‘The Homes for the North’ Group15 - an amalgamation of the 19 largest housing associations in the North of England, who were creating a framework whereby a number of modular companies would have an assurance of orders. Another solution discussed in section 4.1 would be the decentralising of modular construction to more localised factories, creating a balance between lower output and smaller orders. 36
4.0 Results & Analysis
Accent Group Bolton at Home Thirteen Group
Great Places Housing Group Home Group Ltd
Rochdale Boroughwide Housing Onward Homes
The Guiness Partnership Karbon Homes
Gentoo Group
Together Housing Group
Yorkshire Housing
Incommunities Jigsaw Homes
Torus Group
The Riverside Group
Wakefield and District Housing Homes for the North Group
FRAMEWORK Fig.4.11 - Frameworks across the UK, similar to the Homes for the North Group, would result in an assurance of orders for volumetric housing companies
4.3 Key Issue 3: A New Way of Working for the UK Construction Industry (MANAGEMENT)
37
Premier Modular
Walker Modular Urban Splash
Simply Modular Ilke Homes
‘We need a new approach here, across procurement contracts and cost models.’16 Mike De’ath, Partner at HTA Design The final key issue stated by all the Interviewees highlights how MMC has struggled in the UK due to the construction industry’s adherence to previous methods of procurement, and the inflexibility of current systems to accommodate modular design. Due to having experience working with volumetric systems, both Interviewee 2 and 3 noted that these programme differences created knock-on effects for other parts of the construction sequence. With Interviewee 2’s project, having to sort more of the programme beforehand, and the required lead-in times for the modules, was an issue for the primary contractor. Due to their inexperience with modular systems, they considered building it traditionally an easier option, as ‘… they could get on with it straight away, whereas they would have had to have waited for the modular units to be built and done out…’17. Some developers have tried to create a workaround for this inexperience by engaging the supplier as the primary contractor, a solution suggested by Interviewee 1 - ‘…what you need is that the manufacturer is also the constructor…’.18 However, a report by AECOM states that this creates other issues due to the supplier’s inexperience at contracting19. One example where this solution has
Modular Homes: Why Not Sooner?
Project Manager / Client Representative
Developer Supplier / Contractor
Contractor Suppliers
Lead Consultant Lead Consultant Other Consultants Cost Consultant CDM Coordinator Specialist Consultants
Lead Designer Other Consultants Design Team Architect Structural Engineer
Cost Consultant CDM Coordinator Specialist Consultants
Lead Designer
Direct Communication
Sub-Contractors
Design Team Architect
Services Engineer
Structural Engineer
Specialist Designers
Services Engineer
In-house Design Team Architect Structural Engineer Services Engineer Specialist Designers Swan Housing
Specialist Designers
Fig.4.12 - Current construction management structure, vs. Swan Housing's system
worked comes from Swan Housing, who act as the developer, builder, and asset manager on their housing schemes20, creating a closed system where they have full control and utilise their own modular product. These differences in programme can severely affect build times if not accounted for, as the sequencing of volumetric construction is incredibly rigid compared to traditional construction, where sections often happen in parallel. For Interviewee 3, these differences were noticeable when one of the modular suppliers didn’t adhere to the programme and delayed the arrival of their units to site, which slowed the entire project. As well as this, they stated that getting the contractor to work in a different way had also been challenging. Wholesale changes to how contractors and construction programmes are managed will begin to occur as modular design becomes more ubiquitous within the UK housebuilding industry. As contractors will have previous experience on how to structure their programme to accommodate modular systems, this issue is unlikely to be a key barrier in a few years. Instead of trying to change existing contracts and procurement methods, another solution would be the creation of a separate construction board, dedicated entirely to modular construction. Whereas 38
4.0 Results & Analysis
TRADITIONAL SITE BUILT CONSTRUCTION - SEQUENTIAL PROCESS Design, Permitting, Engineering, Approval Process
Site Preparation, Civil Engineering, Infrastructure
FINIS H
Fig.4.13, 4.14 - Timeline comparisons and cost differences between traditional and off-site construction processes
Site Construction, Mechanical Installation, Finish Work
Design, Permitting, Engineering, Approval Process
Site Preparation
Assembly
Manufacturing
TENDER TIME
CONSTRUCTION
ABILITY TO INFLUENCE DESIGN
ABILITY TO INFLUENCE DESIGN
DESIGN
C O S T I M PA C T O F D E S I G N C H A N G E S
MANUFACTURE & ASSEMBLY
C O S T I M PA C T O F D E S I G N C H A N G E S
DESIGN & BUILD
FIN IS H
OFF-SITE CONSTRUCTION - CONCURRENT PROCESS
DESIGN
M A N U FA C T U R E
A S S E M B LY
TIME
countries such as Australia have design guides that go into building compliance for modular design, the aforementioned design guides in the UK don’t discuss this, giving volumetric housing a severe disadvantage. In Australia, the Modular Construction Codes Board was set up in early 2013 by Monash University in Melbourne to create ‘adequate support material to reference modern forms of construction’21. Work undertaken by this board led to the release of a draft code for the design of modular structures in May 201722, allowing MMC in Australia to be recognised as a different method of construction, and not be tied to previous regulations which often aren’t applicable to OSM. The establishing of a similar board in the UK would allow for the creation of separate building regulations for modular systems, giving members of the construction industry coherent information on how to achieve building compliance when creating structures that use MMC.
39
Modular Homes: Why Not Sooner?
4.4 Other Issues Perception (PERCEPTION)
Whilst not considered ‘key issues’ by the author, other challenges brought up by the Interviewees are discussed below. The first of these was the negative perception of prefabricated construction, an issue discussed in section 2.2. A study by Home Group showed that whilst 75% of people could correctly identify a shipping container home as ‘modular’, only 11% could identify a design by Ilke Homes as ‘modular’23, highlighting the general public’s limited grasp on what modern modular construction entails. Interviewee 3 agreed with this and reckoned that the general public would struggle to tell which units had been built volumetrically instead of traditionally at the Innovation Village. Interviewee 1 also discussed the perception of modular within the banking sector, as they struggled to get financial security on their social houses that have used offsite construction, with the statement of ‘well what if they all fail?’ – as they consider factory-built modular homes to have the potential for widespread defects. However, one of the often cited benefits of volumetric construction is its superior build quality, and the litany of issues within traditionally built new homes, with a survey by the All Party Parliamentary Group in 2017/18 finding that 99% of respondents had reported issues with their homes24 - means that this can be better attributed to a lack of pertinent knowledge.
Reliabilty of the company
66%
Superior product quality & performance
58%
Convinced by the sales person’s explanation
55%
Good proposal that reflects expectations Good post-purchase services
15%
Good external appearance & design
14%
Recommendation from acquanitance
Fig.4.15 - Responses from a 2014 survey of Japanese customers on their reasons for choosing a prefabricated home
24%
Enabled to confirm the actual products 0%
12% 10% 20%
40%
60%
80%
Percentage of Respondents
40
4.0 Results & Analysis
One country that has overcome negative public perception of its prefabricated homes is Japan. Due to strict regulations and constraints, early attempts at modular homes were often bland boxes, which were negatively received by the public. To combat this perception, the Japanese housing industry switched the discussion surrounding modular homes from one of affordable construction to one of quality, citing the benefits discussed earlier, such as incredibly tight quality control of factory-made housing. Further to this, the Ministry of Trade established the Japanese Prefabricated Construction Suppliers and Manufacturers Association (JPA) to further improve prefabricated housing’s public image. As highlighted in Section 2.1 this seems to have worked, as Japan’s modular housing industry sold roughly 140,000 homes in 2014, almost 16% of the total new housing stock that year25. With these housebuilders now investing into UK modular companies26 we may begin to see a similar approach in this country. If not, the forming of a similar governmental body in the UK, acting as a subsidiary of Homes England, would be one way to move the public perception of modular homes away from 50s prefabs.
Design Limitations (SYSTEM)
Another challenge facing volumetric systems is the limitations on exterior design options. This issue is inextricably linked to prior key issues, with the need to transport the module limiting its size, and the need to produce them at a large scale to be economically viable reducing the scope for bespoke elements. Whilst using one type of modular system on a development can be aesthetically pleasing in small quantities, if rolled out across larger developments this can result in a large area of similar looking houses, meaning the scheme could struggle to meet the planning requirements of a ‘well-planned’ housing development27, an issue mentioned by Interviewee 3. Furthermore, they stated that a typical housing development consists of a mixture of house types, which means that one workaround would be using multiple modular suppliers within the same housing scheme. Whilst this solution is similar to the scenario found at the Gateshead Innovation Village, they’ve required an on-site contractor to oversee the project, and ensure the programme is sequenced correctly – something that isn’t required with traditional developments. Another workaround is for the modular supplier to provide a range of options to create different house types, a system offered by Ilke Homes. This might not be possible for other volumetric housebuilders, who don’t have the manufacturing capacity to build multiple housing types. Whilst both Interviewee 1 and 3 were worried about housing type constraints, these were localised to suburban low-rise developments. With medium to high-rise developments within towns and cities, a lack of uniformity would be much easier to accomplish, as different stackings of modules could be used to create unique buildings.
41
Modular Homes: Why Not Sooner?
Fig.4.16-4.20 - Ilke Homes' modular house types
42
4.0 Results & Analysis
REFERENCES
Waugh Thistleton Architects, 2019. Nu Build Modular Design Guide. pg36 Ilke Homes, 2019. It All Stacks Up: Building Homes Using Volumetric Manufacturing. [Online] Available at: https://ilkehomes.co.uk/wp-content/uploads/2019/06/FINAL-ilke-MMC-guide-210619.pdf [Accessed 2 September 2019]. pg7 3 Paul, J., 2019. Interview with Interviewee 3 [Interview] (3 September 2019). 4 Bauman, I., 2019. MassBespoke: Building InCommon. Bradford: TEDx. [Lecture] (16 April 2019) 5 Ilke Homes, 2019. It All Stacks Up: Building Homes Using Volumetric Manufacturing. pg10 6 Paul, J., 2019. Interview with Interviewee 1 [Interview] (2 August 2019). 7 The Guardian, 2018. 'UK Housebuilding Revolution': ÂŁ65,000 Prefab Homes Go Into Production. [Online] Available at: https://www.theguardian.com/society/2018/nov/30/uk-housebuilding-revolution-65000prefab-homes-go-into-production [Accessed 22 August 2019]. 8 Interviewee 3 stated that the superstructure cost of an equivalent traditionally built 68m2 semidetached home in the Innovation Village was ÂŁ62,000 9 Lopez, D. & Froese, T. M., 2016. Analysis of Costs and Benefits of Panelized and Modular Prefabricated Homes. Procedia Engineering, Volume 145, pg1291-1297. 10 Pinsett Masons, 2017. Modular Construction in UK Housing: An Overview of the Market, the Players and the Issues. 11 Paul, J., 2019. Interview with Interviewee 1 [Interview] (2 August 2019). 12 They also noted it was a higher specification system than the others available, which increased costs. 13 Cooperative Research Centre for Construction Innovation, 2007. Off-Site Manufacture in Australia: Current State and Future Directions. pg36 14 Paul, J., 2019. Interview with Interviewee 3 [Interview] (3 September 2019). 15 Homes For The North, 2019. Homes For The North. [Online] 1 2
43
Modular Homes: Why Not Sooner?
Available at: http://www.homesforthenorth.co.uk/ [Accessed 10 September 2019]. 16 Ilke Homes, 2019. It All Stacks Up: Building Homes Using Volumetric Manufacturing. pg13 17 Paul, J., 2019. Interview with Interviewee 2 [Interview] (9 August 2019). 18 Paul, J., 2019. Interview with Interviewee 1 [Interview] (2 August 2019). 19 AECOM, 2017. Cost Model: Modular Construction, s.l.: Building Magazine. 20 Chevin, D., 2018. Is Offsite Really The Answer To Our Housing Problems?. [Online] Available at: http://www.bimplus.co.uk/people/offsite-really-answer-our-housing-problems/ [Accessed 24 August 2019]. 21 Modular Construction Codes Board, 2019. About MCCB. [Online] Available at: http://www.mccb.org.au/mccb [Accessed 13 September 2019]. 22 Modular Construction Codes Board, 2017. Handbook for the Design of Modular Structures. Melbourne: Monash University. 23 Home Group, 2019. What Is Modular Housing?. [Online] Available at: https://www.homegroup.org.uk/Corporate/Development-Partners/Gateshead-InnovationVillage/What-is-modular-housing [Accessed 3 August 2019]. 24 Wilson, W. & Rhodes, C., 2019. New-build Housing: Construction Defects - Issues and Solutions (England), London: House of Commons. 25 Aitchison, M. et al., 2018. Prefab Housing and the Future of Building: Product to Process. pg94 26 Urban Splash, 2019. Boost For Housing Market As Japan’s Biggest Housebuilder, Sekisui House, Moves Into UK. [Online] Available at: https://www.urbansplash.co.uk/resources/boost-for-housing-market-as-japans-biggesthousebuilder-sekisui-house-moves-into-uk [Accessed 13 September 2019]. 27 Part 12, Point 127a of the National Planning Policy Framework states that ‘well-designed’ places should ‘establish or maintain a strong sense of place, using the arrangement of streets, spaces, building types and materials to create attractive, welcoming and distinctive places to live, work and visit…’
44
Modular Homes: Why Not Sooner?
5.0 CONCLUSIONS
5.1 - Discussion
Why Not Sooner? was the original question of this study, related to why volumetric construction wasn’t as widespread within the UK housing industry as it could be, as it is now being touted as one of the key methods of solving the UK’s housing shortfall. Through the course of writing this report, modular systems were found to be more widespread in high-density housing than the author first thought, with apartments often utilising small-scale modules such as bathroom pods, and high-density developments beginning to integrate volumetric modules. Also, with recent government support for MMC to help meet climate targets, as well as a commitment to meet housing construction targets, more companies see this as the right time to invest in low-density volumetric housing methods. However, this governmental support meant that whilst there had been a lot of research into the benefits of volumetric construction, few had looked into why there hadn’t been a greater uptake. Whilst Pan et al. did look into these issues by talking to the larger housebuilders, there hadn’t been any recent reports that discussed the issues, even though the uptake in modular systems is considerably higher now than it was 15 years ago.
Fig 5.1 - Legal & General's modular housing factory
Due to the lack of replies to interview requests, there was insufficient data to provide a quantified look at the key issues facing modular housing. The interviews that were undertaken highlighted that the current barriers for volumetric housing construction in the UK are still similar to those discussed by Pan et al., with the module cost, coupled with the difficulty of transporting them to housing developments, and a construction industry that is slow to change attributing to volumetric construction’s low market share. Whilst the recent uptake and interest in modular systems is likely to make costs decrease as the percentage of the housing industry related to modular construction goes up, another solution is the decentralisation of volumetric construction, with temporary factories localised to housing developments. Whilst these pop-up factories would likely still be owned by the big housebuilders, they would be able to combine the benefits of panellised systems and volumetric construction and are the most viable option 46
5.0 Conclusions
for forming a middle ground between traditional and modular housebuilding. Also, learning from methods undertaken by countries with established modular housing industries, such as Japan and Australia, would allow the UK construction industry to set itself up to better accommodate MMC.
5.2 - Further Research
To successfully build upon the issues analysed in this report, wider input from the UK housing industry would be necessary. Whilst the interviews undertaken by the author were incredibly useful, they only represented a small sample of the wider market, with a predominantly northern look at the challenges facing modular housing, as well as only having one Interviewee who had undertaken volumetric construction. A wider set of Interviewees would allow for a more informed look at the current state of the housing industry and would be a better driver for further discussion. More research into other solutions to the challenges discussed within this report would be a suitable way to measure the effectiveness of volumetric construction, and whether MMC alternatives, such as panellised construction, are more viable in the long term.
47
Modular Homes: Why Not Sooner?
48
6.0 Bibliography
6.0 BIBLIOGRAPHY
6.1 Books / Journals
49
AECOM, 2017. Cost Model: Modular Construction, s.l.: Building Magazine. Aitchison, M. et al., 2018. Prefab Housing and the Future of Building: Product to Process. London: Lund Humphries Publishers. Arif, M., Goulding, J. & Rahimian, F. P., 2012. Promoting Off-Site Construction: Future Challenges and Opportunities. Journal of Architectural Engineering, 18(2). Cooperative Research Centre for Construction Innovation, 2007. Off-Site Manufacture in Australia: Current State and Future Directions, Brisbane: Cooperative Research Centre for Construction Innovation. Court, P. F., Pasquire, C. L., Gibb, G. F. & Bower, D., 2009. Modular Assembly with Postponement to Improve Health, Safety, and Productivity in Construction. Practice Periodical on Structural Design and Construction, 14(2). Department for Communities and Local Government, 2017. Fixing Our Broken Housing Market, London: Department for Communities and Local Government. Dörrhöfer, A., Staib, G. & Rosenthal, M., 2008. Components and Systems: Modular Construction – Design, Structure, New Technologies. Basel: Birkhäuser. Edge, M. et al., 2002. Overcoming Client and Market Resistance to Prefabrication and Standardisation in Housing, Aberdeen: Robert Gordon University. Ferdous, W. et al., 2019. New Advancements, Challenges and Opportunities of Multi-Storey Modular Buildings – A State-of-the-Art Review. Engineering Structures, Volume 183, pg883-893. Generalova, E. M., Generalov, V. P. & Kuznetsova, A. A., 2016. Modular Buildings in Modern Construction. Procedia Engineering, Volume 153, pg167-172. Giriunas, K., Sezen, H. & Dupaix, R. B., 2012. Evaluation, Modeling and Analysis of Shipping Container Building Structures. Engineering Structures, Volume 43, pg48-57. Grębowski, K. & Kałdunek, D., 2017. Using Container Structures in Architecture and Urban Design. IOP Conference Series: Materials Science and Engineering, Volume 245.
Modular Homes: Why Not Sooner?
Imperiale, A., 2012. An American Wartime Dream: The Packaged House System of Konrad Wachsmann and Walter Gropius. Philadelphia, ACSA. Knaack, U., Chung-Klatte, S. & Hasselbach, R., 2012. Prefabricated Systems: Principles of Construction. Basel: Birkhauser. Larsson, M., Kaiser, A. & Girhammar, U. A., 2012. Multi-Storey Modular Manoeuvres - Innovative Architectural Stacking Methodology Based on Three Swedish Timber Building Systems. Auckland, World Conference on Timber Engineering. Lawson, M., Ogden, R. & Bergin, R., 2012. Application of Modular Construction in High-Rise Buildings. Journal of Architectural Engineering, 18(2). Lawson, M., Ogden, R. & Goodier, C., 2014. Design in Modular Construction. Boca Raton: CRC Press. Lopez, D. & Froese, T. M., 2016. Analysis of Costs and Benefits of Panelized and Modular Prefabricated Homes. Procedia Engineering, Volume 145, pg1291-1297. Ministry Of Housing, Communities & Local Government, 2019. National Planning Policy Framework, London: Ministry Of Housing, Communities & Local Government. Modular Construction Codes Board, 2017. Handbook for the Design of Modular Structures. Melbourne: Monash University. Oakley, M., 2017. The Value of Off-Site Construction to UK Productivity and Growth, London: WPI Economics. Pan, W., Gibb, A. G. F. & Dainty, A. R. J., 2007. Perspectives of UK Housebuilders on the Use of Offsite Modern Methods of Construction. Construction Management and Economics, 25(2), pg183-194. Pan, W. & Goodier, C., 2012. House-Building Business Models and Off-Site Construction Take-Up. Journal of Architectural Engineering, 18(2). Parliamentary Office of Science and Technology, 2003. Modern Methods of House Building, London: Parliamentary Office of Science and Technology. Rey, E., 2012. Swisswoodhouse, an Innovative Concept for Sustainable Modular Housing. Lima, Proceedings of PLEA 2012, 28th International Conference on Passive and Low Energy Architecture, Lima, Peru, 2012. Stephens, M. et al., 2018. 2018 UK Housing Review, Coventry: Chartered Institute of Housing. Sun, Z., Mei, H. & Ni, R., 2017. Overview of Modular Design Strategy of the Shipping Container Architecture in Cold Regions. IOP Conference Series: Earth and Environmental Science, 63(1). Tabsh, S. W. & Abdelfatah, A. S., 2009. Influence of Recycled Concrete Aggregates on the Strength Properties of Concrete. Construction and Building Materials, 23(2), pg1163-1167. Vijayalaxmi, J., 2010. Towards Sustainable Architecture - A Case With Greentainer. Local Environment The International Journal of Justice and Sustainability, 15(3), pg245-259. 50
6.0 Bibliography
Waugh Thistleton Architects, 2019. Nu Build Modular Design Guide. London: Swan Housing Association. Wilcox, S., Perry, J., Stephens, M. & Williams, P., 2017. 2017 UK Housing Review, Coventry: Chartered Institute of Housing. Wilson, W. & Rhodes, C., 2019. New-build Housing: Construction Defects - Issues and Solutions (England), London: House of Commons.
6.2 Web Resources
51
BoKlok, 2019. About Us. [Online] Available at: https://www.boklok.com/about-us/ [Accessed 7 June 2019]. Chevin, D., 2018. Is Offsite Really The Answer To Our Housing Problems?. [Online] Available at: http://www.bimplus.co.uk/people/offsite-really-answer-our-housing-problems/ [Accessed 24 August 2019]. Geoghegan, T., 2013. Why Do So Many Americans Live in Mobile Homes?. [Online] Available at: https://www.bbc.co.uk/news/magazine-24135022 [Accessed 7 June 2019]. Home Group, 2019. What Is Modular Housing?. [Online] Available at: https://www.homegroup.org.uk/Corporate/Development-Partners/Gateshead-InnovationVillage/What-is-modular-housing [Accessed 3 August 2019]. Homes For The North, 2019. Homes For The North. [Online] Available at: http://www.homesforthenorth.co.uk/ [Accessed 10 September 2019]. Hurst, W. & Waite, R., 2019. Urban Splash Team Set to Build Huge Modular Housing Scheme for New Town. [Online] Available at: https://www.architectsjournal.co.uk/news/urban-splash-team-set-to-build-huge-modularhousing-scheme-for-new-town/10039691.article [Accessed 3 January 2019]. ICE, 2018. Minimum Space Standards. [Online] Available at: https://www.designingbuildings.co.uk/wiki/Minimum_space_standards [Accessed 20 July 2019]. Ilke Homes, 2019. It All Stacks Up: Building Homes Using Volumetric Manufacturing. [Online] Available at: https://ilkehomes.co.uk/wp-content/uploads/2019/06/FINAL-ilke-MMC-guide-210619.pdf [Accessed 2 September 2019].
Modular Homes: Why Not Sooner?
Jessel, E., 2018. London Mayor to Fund Toolkit for Offsite Homes. [Online] Available at: https://www.architectsjournal.co.uk/news/london-mayor-to-fund-toolkit-for-offsitehomes/10029946.article. [Accessed 3 January 2019]. Jessel, E., 2018. Stop Funding 'Hothouse' Modular Homes, MPs Tell Government. [Online] Available at: https://www.architectsjournal.co.uk/news/stop-funding-hothouse-modular-homes-mpstell-government/10033689.article [Accessed 2 January 2019]. London Assembly, 2017. Designed, Sealed, Delivered: The Contribution of Offsite Manufactured Homes to Solving London's Housing Crisis. [Online] Available at: https://www.london.gov.uk/sites/default/files/london_assembly_osm_report_0817.pdf [Accessed 3 January 2019]. Modular Construction Codes Board, 2019. About MCCB. [Online] Available at: http://www.mccb.org.au/mccb [Accessed 13 September 2019]. Pinsett Masons, 2017. Modular Construction in UK Housing: An Overview of the Market, the Players and the Issues. [Online] Available at: http://constructingexcellence.org.uk/wp-content/uploads/2017/02/graham-robinsonpinsent-masons-14022017.pdf [Accessed 3 January 2019]. Pitcher, G., 2019. ShedKM Reveals Plans for Modular Manchester Housing. [Online] Available at: https://www.architectsjournal.co.uk/news/shedkm-reveals-plans-for-modular-manchesterhousing/10040473.article [Accessed 5 March 2019]. Select Committee on Economic Affairs, 2016. Building More Homes. [Online] Available at: https://publications.parliament.uk/pa/ld201617/ldselect/ldeconaf/20/20.pdf [Accessed 22 March 2019]. The Guardian, 2017. Prefab Sprout: Off-the-peg Homes Bid to Ease UK Housing Crisis. [Online] Available at: https://www.theguardian.com/money/2017/jul/15/prefab-sprout-off-the-peg-homes-bidto-ease-uk-housing-crisis [Accessed 12 March 2019]. The Guardian, 2018. 'UK Housebuilding Revolution': ÂŁ65,000 Prefab Homes Go Into Production. [Online] Available at: https://www.theguardian.com/society/2018/nov/30/uk-housebuilding-revolution-65000prefab-homes-go-into-production [Accessed 22 August 2019].
52
6.0 Bibliography
The Independent, 2009. Ikea Homes Development Falls Flat. [Online] Available at: https://www.independent.co.uk/property/house-and-home/ikea-homes-development-fallsflat-1501231.html [Accessed 13 September 2019]. United States Census Bureau, 2019. U.S. and World Population Clock. [Online] Available at: https://www.census.gov/popclock/ [Accessed 7 June 2019]. Urban Splash, 2019. Boost For Housing Market As Japan’s Biggest Housebuilder, Sekisui House, Moves Into UK. [Online] Available at: https://www.urbansplash.co.uk/resources/boost-for-housing-market-as-japans-biggesthousebuilder-sekisui-house-moves-into-uk [Accessed 13 September 2019]. Urban Splash, 2019. Welcome to House by Urban Splash. [Online] Available at: https://www.housebyurbansplash.co.uk/ [Accessed 3 January 2019]. Wikipedia, 2019. Habitat 67. [Online] Available at: https://en.wikipedia.org/wiki/Habitat_67 [Accessed 20 July 2019]. Wikipedia, 2019. Prefabricated Building. [Online] Available at: https://en.wikipedia.org/wiki/Prefabricated_building [Accessed 25 March 2019]. Wilson, R., 2018. ShedKM Completes Modular Townhouses in North Shields for Urban Splash. [Online] Available at: https://www.architectsjournal.co.uk/buildings/shedkm-completes-modular-townhouses-innorth-shields-for-urban-splash/10019669.article [Accessed 3 January 2019]. Wilson, W. & Barton, C., 2018. Tackling the Under-Supply of Housing in England. [Online] Available at: http://researchbriefings.files.parliament.uk/documents/CBP-7671/CBP-7671.pdf [Accessed 3 January 2019]. Yorkon, 2016. The Advantages of a Modular Building. [Online] Available at: https://www.yorkon.co.uk/news-and-views/advantages-modular-building/ [Accessed 16 March 2019].
53
Modular Homes: Why Not Sooner?
6.3 Misc. Resources
Bauman, I., 2019. MassBespoke: Building InCommon. Bradford: TEDx. [Lecture] (16 April 2019) Edison, T., 1917. Process of Constructing Concrete Buildings. United States of America, Patent No. 1,219,272. Lewis, B. & Hinds, D., 2016. Inquiry on the Economics of the UK Housing Market [Interview] (22 March 2016). Paul, J., 2019. Interview with Interviewee 1 [Interview] (2 August 2019). Paul, J., 2019. Interview with Interviewee 2 [Interview] (9 August 2019). Paul, J., 2019. Interview with Interviewee 3 [Interview] (3 September 2019). Waugh, A., 2019. Wood In Architecture. Sheffield [Lecture] (29 March 2019).
6.4 Figures
Figures are Author's Own, unless referenced below Cover Image - Urban Splash, 2019. Fab House. [Online] Available at: https://www.housebyurbansplash.co.uk/fab-house/ [Accessed 27 March 2019] Figure 1.1 - Fearn, H., Shaw, V., 2016. Housing Crisis is Weakening the Bonds Between Generations. [Online] Available at: https://www.independent.co.uk/news/uk/home-news/housing-crisis-isweakening-the-bonds-between-generations-a7314686.html [Accessed 27 March 2019] Figure 1.2 - Select Committee on Economic Affairs, 2016. Building More Homes. [ebook] Available at: https://publications.parliament.uk/pa/ld201617/ldselect/ldeconaf/20/20.pdf With additional data from: Wilson, W. & Barton, C., 2018. Tackling the Under-Supply of Housing in England. [ebook] Available at: http://researchbriefings.files.parliament.uk/documents/CBP-7671/CBP-7671.pdf pg5 Figure 1.3 - Department for Communities and Local Government, 2017. Fixing Our Broken Housing Market London: Department for Communities and Local Government, 2017. Figure 1.5 - Lawson, M., Ogden, R. & Goodier, C., 2014. Design in Modular Construction. Boca Raton: CRC Press. pg3 Figure 1.6 - George Plunkett, 2006. Norwich New Housing Estates. [Online] Available at: http://www.georgeplunkett.co.uk/Norwich/New%20Housing%20Estates/Kett’s%20Hill%20 post-war%20prefab%20homes%20[4707]%201962-09-01.jpg [Accessed 27 March 2019] 54
6.0 Bibliography
Figure 1.7,1.8 - Waugh Thistleton Architects, 2019. Watts Grove. [Online] Available at: http://waughthistleton.com/watts-grove/ [Accessed 07 June 2019]
Figure 2.1 - Kaytons Estate Agents, 2019. Second Round of Urban Splash Development. [Online] Available at: http://kaytons.co.uk/second-round-urban-splash-house-development/ [Accessed 27 March 2019] Figure 2.2 - BoKlok, 2019. About the Homes. [Online] Available at: https://www.boklok.com/about-the-homes/ [Accessed 04 June 2019] Figure 2.3 - Shedkm, 2019. Mansion House. [Online] Available at: https://www.shedkm.co.uk/work/mansion-house/ [Accessed 04 June 2019] Figure 2.4 - Touhey, M. for Dezeen, 2016. World's Tallest Modular High-rise by SHoP Architects Opens in Brooklyn [Online] Available at: https://www.dezeen.com/2016/11/18/worlds-tallest-modular-prefabricated-apartmenttower-shop-architects-brooklyn-new-york/ [Accessed 27 March 2019] Figure 2.5 - MIMOA, 2019. Murray Grove Housing. [Online] Available at: https://www.mimoa.eu/projects/United%20Kingdom/London/Murray%20Grove%20 Housing/ [Accessed 27 March 2019] Figure 2.6 - Pan, W., Gibb, A. G. F. & Dainty, A. R. J., 2007. Perspectives of UK Housebuilders on the Use of Offsite Modern Methods of Construction. Figure 2.7 - Vass, N. for Wikipedia, 2019. Habitat 67. [Online] Available at: https://en.wikipedia.org/wiki/Habitat_67 [Accessed 20 July 2019]. Figure 2.8 - Carniere, L. for Dezeen, 2016. BIG Stacks Shipping Containers to Create Floating Student Housing in Copenhagen Harbour. [Online] Available at: https://www.dezeen.com/2016/09/22/big-bjarke-ingels-shipping-containers-floatingstudent-housing-urban-rigger-copenhagen/ [Accessed 23 September 2019]
55
Modular Homes: Why Not Sooner?
Figure 2.9 - Whitechapel Gallery, 2018. Boxpark Shoreditch. [Online] Available at: http://nunnthewiser.com/wp-content/uploads/2018/05/boxpark.html [Accessed 23 September 2019] Figure 2.10 - MVRDV, 2019. Cancer Centre. [Online] Available at: https://www.mvrdv.nl/projects/108/cancer-centre [Accessed 23 September 2019]
Figure 4.3 - Urban Splash, 2019. Port Loop. [Online] Available at: https://www.urbansplash.co.uk/regeneration/projects/port-loop [Accessed 01 October 2019] Figure 4.4 - Urban Splash, 2019. New Islington. [Online] Available at: https://www.urbansplash.co.uk/regeneration/projects/new-islington [Accessed 01 October 2019] Figure 4.5 - KDS Associates, 2019. Precision Modular Factory. [Photograph] Figure 4.8 - Bauman Lyons, 2019. Built InCommon Conversation 3 - Distributed Fabrication [Online] Available at: https://baumanlyons.co.uk/news/built-incommon-conversation-3-distributed-fabrication [Accessed 14 September 2019] Figure 4.9 - MassBespoke, 2017. MassBespoke Brochure. [Online] Available at: http://www.massbespoke.com/index.html pg9 [Accessed 14 September 2019] Figure 4.13, 4.14 - Waugh Thistleton Architects, 2019. Nu Build Modular Design Guide. London: Swan Housing Association. pg22-23 Figure 4.15 - Aitchison, M. et al., 2018. Prefab Housing and the Future of Building: Product to Process. London: Lund Humphries Publishers. pg95 Figure 4.16-4.20 - Ilke Homes, 2018. 2018 Housetype Portfolio. [Online] Available at: https://www.ilkehomes.co.uk/wp-content/uploads/2018/04/ilke-Homes-HousetypePortfolio-9MB.pdf [Accessed 01 October 2019]
Figure 5.1 - Wilmore, J., 2019. We Take a Look Around L&G's Housing Factory. [Online] Available at: https://www.insidehousing.co.uk/insight/insight/we-take-a-look-around-lgs-housingfactory-60136 [Accessed 07 October 2019] 56
7.0 Appendix
7.0 APPENDIX
7.1 - Interviewee 1
JP: So, I suppose just start by talking through the projects that you’ve done with this [prefab] system I1: We’ve wanted to test off-site construction because there’s been so much talk about it and so little real progress on it, certainly at scale. So, a few years ago, about three years ago I got fed up with having a new product drop into my mailbox every day practically saying, ‘look at our homes, look at this timber frame, look at that’, I was so confused. So we did a piece of work around some options- no its probably even four years ago– I can’t remember how long ago it was, but what we actually ended up doing was we did a piece of work that said why wouldn’t we use a Local Homes1 product because what we liked about Local Homes is that they’re owned by a housing association so their profits go back into social housing, so that works for us, and because that housing association has used that product for years it’s kind of by someone we trust. So we did a piece of work, and the answer was there’s no reason not to use that product, that would be a good thing to start with, so that was why we chose Local Homes in the first place, and that I did a piece of work that kind of looked right across the landscape of off-site construction I suppose and I concluded that for our product, which is basically two-storey family houses, the best products are either gonna be closed panel timber frame or possibly volumetric, although it’s very expensive at the moment, and then possibly some more kind of one-off things such as pods for homeless people. So, our core product is going to be closed panel timber frame for now, volumetric when it becomes affordable – so that was where we kind of left it. So we ploughed on, we did our timber frame pilot, where there were some issues with the product, but overall it was a success I’d say, and I think with any new product, and any new supplier, you have a teething problem with the relationship and learning about the product, and in our case the architect didn’t know about the product, so you know all that kind of stuff we know that about construction so I kind of feel that you almost have to try this product more than once to kind of iterate, build on the relationship in order to get a better result. In terms of price it was very competitive, and the scheme as a whole came out at a very competitive cost. So, although the construction product was more expensive than block-and-brick, the overall scheme, the cost per unit was cheaper than traditional because you were on site for less time
57
Modular Homes: Why Not Sooner?
and all of that, and even with the delay that was built in that was true so that was very positive I think. I mean having said that it was a flat site with no infrastructure so you’d expect the cost to be a bit low– it’s very hard to do an ‘apples with apples’ comparison, but generally we were pleased with the price on that as well. So the reason we then moved on to do Wikihouse2 is because– and I suppose in both of these cases I would say that generally we prefer timber because of the low embodied carbon so that’s my dilemma about volumetric- I’ll come on to volumetric in a moment– we wanted to try another timber product, we wanted to try Wikihouse; do you know about Wikihouse? JP: Yes, I do, yes I1: So we partially wanted to try Wikihouse because we were interested in custom build, interested in the systems behind it – challenging the ideas about how houses are built, and all of that, and we were actually very clear in the first instance that we were gonna test the product – we weren’t going to test that wider agenda, we were just gonna see if this was a product we could use, if this was a product were happy to have houses built from this and so on, do we think it’s a different way of building and designing and all of that. So the big, big problem we had was the site had these terrible terrible abnormals [sic], so– and we weren’t doing- and we were doing management contraction, so we had all the risk back with us so it was just a complete disaster financially for us- well not a disaster, just incredibly expensive– so that was a bit of a shame because it slightly clouded the whole experience of the Wikihouse. But if you try to put all that to one side, you’ll see in the report3 you’ll see we felt– I mean the Wikihouse is definitely more expensive at the moment.4 So we concluded with Wikihouse we actually would use it again, and actually I think, although there are– you know we wanted to test it for the whole digital design and the unskilled labour potentially and all of that, and the future of self-build and customisation, but actually I think we would consider it for our mainstream product if the price was right and I thought we had the right supply-chain and manufacturers and could do it to scale and all that, so I wouldn’t rule it out over Local Homes. JP: So that was something you potentially alluded to in your report was the potential of making it [Wikihouse] into a bespoke system for yourself, is that something you see with Wikihouse being quite viable? I1: That’s right. And actually, what the person who ran that site said was that she would not go to a 50unit site now, she would do another pilot. You know you might do 5 or 10 [units] because there’s still- the 58
7.0 Appendix
thing about Wikihouse is- the difference with Local Homes is that that product has been up and running for years, Wikihouse is so new, I think we’re the first social landlord to build a [Wiki]house, it’s so new and actually they are learning as well– they learnt a lot from us– those who designed this product as they’ve been able to refine it, and it needs a bit more refining and actually a lot of people do say this about build off-site manufacturers is that they need to work with them on two or three or four iterations to get the price right– to finetune all of it. So, with Wikihouse certainly we’d do another pilot before we went large with it. But it was quite interesting because one question we wanted to ask of them was could we get it to scale and I think possibly we could. So those are the two tests done, and the next thing I would like to do I think, but I am in two minds about it, is a volumetric test. And we probably would– we have a site of about 50 homes- its flat, tends to lend itself quite well [to volumetric]- we hope, that we’re trying to buy, we haven’t got it yet, we might test it there. My reservations that I have on volumetric is the constraints on the housing types, we’re working with a load of other housing associations in the north of England and we’re agreeing layouts and all this kind of stuff for off-site construction and volumetric so I think that can be sorted. JP: Could you just briefly expand on what you mean by the constraints of it. Is it just the sizing of it? I1: Yeah, it’s the fact they have to go on a lorry and that fixes the dimensions, so you tend to end up with long thin houses. The other big constraint for me is this business of the embodied carbon, they’re all made of steel and concrete. So, one of my questions is there a timber volumetric housing? JP: Yes, there is, so Waugh Thistleton down in London do buildings out of CLT. I1: Yeah, and is that really expensive? Because that the only thing I have heard is that CLT comparative. And do they do low rise rather than high rise? JP: They do a combination of the two so they’ve done- I can send you a link. To be honest I don’t know if they- if they’ve done small ones in CLT, they’re usually high-rise kind of larger scale people. But they have recently released a design guide in London, it is London based but it gives you a general idea of what kind of works. I1: Yeah if you wouldn’t mind sending that. What we find so often is that the people who are really experienced in off-site are all building high-rises and are not adapted to- anyway it would be good to see. Anyway so, you’ve probably heard of Ilke Homes have you?
59
Modular Homes: Why Not Sooner?
JP: Yes I1: So they’re the people who everyone seems to be turning to, and I think that’s for a couple of reasons: one is that because they’ve come at a key moment, it’s a constructor that’s very used to the social rented market and our product basically, so that’s one thing. And the other thing is that they seem to have got their price pretty affordable. But I think all this is a little bit to be tested and its can we get a decent design with their product- product’s pretty rigid that they design, they produce so yeah that I was one I was thinking of testing but I’m not sure at the moment, I might look at some other sorts. Again, if you’ve got another other good suggestions generally on volumetric let us know. So, we’ve done this study with build off-site for the housing associations in the north to scan the industry and test different things, but yeah if you find any that would be good. And why would I want to turn to volumetric, I suppose, obviously more of it is finished off-site, so it feels that it’s a logical extension. My personal view is that we will always need volumetric and closed panel timber frame because lots of sites won’t suit volumetric. It’ll always be horses-for-courses, so I think there’s never just one product, but we obviously want to limit the number, we would like the limit the relations we have with different products rather than just endlessly testing things. JP: So maybe in the future do you see that as one of the potential barriers going fully volumetric is the site-by-site basis look at it? I1: Yeah, I just think sloping sites, sites that are difficult to get at aren’t going to work particularly well. I think flat sites volumetric will be good, and that probably will be a lot of sites, it just depends doesn’t it. We’re in Yorkshire, and there’s hills, it’s not necessarily always going to work. So, I think you just have to have one or two options. Then I like Wikihouse because its bespoke and potentially a bit more easy to customise. So, to say those three products, volumetric we really like, Local Homes and Wiki, it’s a really good mix to have at our fingertips… so we’ll see. JP: Something else you briefly talked about in your report – did you get any help from General Panels about their systems, or were you given this architect who wasn’t related or wasn’t in the knowledge about the project? I1: Yeah that’s the thing. The architect we were using- so what we did, we hired an architect then quite late on we wanted this product. So yeah, we said we wanted to use this product, we just decided quite late on in the scheme. So, we had the architect, Local Homes weren’t particularly collaborative because they use their in-house architects all the time.
60
7.0 Appendix
JP: Ok, so they do have their own in-house architect then? I1: Yeah, they have an in-house architect and they- I don’t know if they just weren’t being helpful or if they’re just not used to working with other architects but all that wasn’t particularly collaborative. But you know, maybe our architects weren’t brilliant at liaising, but it was just that relationship wasn’t very- they were all learning on the job a bit which probably wasn’t helpful. But that is an important thing, you need the architect to understand the product, that’s why you really ought to try and procure teams, you know, design and manufacturing teams and then you need the constructor to understand the product so really what you need is that the manufacturer is also the constructor, and then you just have a groundworker who does the rest. So the box is all done by them- so we knew all that before we did these tests- there’s something about, even though we knew that- we knew we weren’t going to try and use a completely new approach because we didn’t want to layer on too much learning in one contract, so we stuck with traditional D&B5 stuff, but we knew that would add cost and other complexity because we nominated the product, it wasn’t what they wanted necessarily. So, we knew all of that, but it’s interesting nonetheless sometimes you have to go through it yourself to learn what that really is. Because people say the relationship you’ve then got to interface and all what does that really mean, and we now know what that means actually. So that was good to learn all of that, and I think we know what we would do differently. JP: No, that’s interesting. So, I assume you don’t have an architectural team within your association? I1: No, we don’t have an in-house team no. We’re going to go out and procure a panel of architects quite soon, and I think one of our criteria will be that they understand off-site construction. Also, this Homes for the North group I was talking about, they’re going for a series of manufacturers and a series of architectscontract managers and stuff. So, I think they’ll be much more tuned in to off-site construction things so that will help. JP: Going back to something you said quite early to the start, so you said you started to do prefab about three of four years ago, what was your decision behind starting to do it then? I1: So yeah, all the reasons everybody else gives really: environmental sustainability, better build quality, less time on site, labour skills going, Brexit – what that’s going to do for labour and materials. So, all the same reasons as everyone else really. Trying to decide we have as much as possible to get our product much more competitive in price. You know our schemes are so variable, because we use different house types, different products, we were just trying to standardise how many types of construction, streamline that manufacture process rather than redoing everything every time – all of those things. What’s so good about Wiki; knocking out different types, the nice thing about Local [Homes] is the economic benefits accrue to another housing association, there’s some nice things about local jobs, different sorts of jobs. The Local factory they’ve recruited pretty much all their workforce from the estate they’re in, which was a very high unemployment area, things you know like that, it’s really nice– they have women working there. 61
Modular Homes: Why Not Sooner?
JP: So I know it’s a change then- do you have much contact with other housing associations, and have you noticed their change as similar to yours where they’re all thinking this is the way we want to go now, away from traditional build? I1: The Homes for the North group, you can probably Google them actually, but anyway they’re the biggest nineteen housing associations in the north of England, and I sort of gate-crash their party, we’re not in that group, we’re not big enough. But what they’re doing, basically they’ve talked to government and said look we need to get to scale with off-site, we need to give this a good push, so we’re trying to procure a framework whereby it’s not that we’re not procuring it together it’s that we’re saying we’ll generally buy from this framework so you can be sure that a lot of units are coming through because collectively- I’m not sure how many thousands of units they build a year, the manufacturer can expect to get a decent size of service so I think there’s something about getting to scale. I’m not totally convinced that getting to scale is the thing but its more about how predictable the supply isJP: That’s what I’ve noticed I1: Have you spoken to Irena Bauman about this? JP: Have I spoken to who sorry? I1: Irena Bauman from Bauman Lyons, very good person to talk to if you get the chance on this sort of stuff. One of the things she says, and I’m sure she’s absolutely right, is these big factories, you know they pump a load of money, they create these mega factories that are entirely dependent on this huge order book to be viable, and you never get that order book so they all go bust and you get this white elephant thing. So that’s the history in the last 10-15 years of this thing, so her thing is if you do lots of smaller medium size businesses who can operate at a scale, and in fact Local Homes, they got a grant for their factory to produce 100 homes and they’ve built those almost all themselves- so anything they sell over that- so you know that’s much more resilient, and they can get a predictable order book much more easily. So Irena’s a great fan you know of ‘not too big’– the networks not necessarily there, so that’s why I think again we don’t want to find just one product, we want to find a few products, where each of them could you know- you almost don’t want one manufacturer to get too big. It’ll be interesting to see if the Urban Splash volumetric becomes affordable- actually I keep meaning to talk to them, they’re another one to talk to. Because we’ve seen that product when it was owned by SIG6 and Urban Splash bought it off SIG so we know that product and we know its twice of what we can afford. JP: Oh really? I1: Yeah, so their ‘box’ is a higher spec than what we would normally build, but their superstructure was roughly double the ones we were looking at, so it’s really- it’s partially about size, but I also think it’s 62
7.0 Appendix
actually just because they weren’t making enough of them, so it’ll be interesting to see now that Urban Splash have got that factory whether they can churn out enough to bring the price down significantly. So that would be good… can’t remember what we were talking about… where had we got to. JP: Nah that’s interesting, we were just talking about the generalI1: -oh yeah, whether anyone else was going to, yes, I think we got a bit hung up on scale. But it’s interesting, it’s so interesting being in this group, because I’m sat at the table, we have 6000 homes, some groups have 20 or 40,000 homes, Home Group have 100,000 homes, and Yorkshire Housing have got- you know all of them have loads of homes, loads loads bigger than us, and with the exception of Home Group have done this Innovation Village– you know that? JP: I’m not sure I do actually I1: So, they tested a load of different products on one site. They did the BoKlok scheme a couple of years ago, but then they tested, I can’t remember if its four or six. So it’s really worth talking to- there’s a really nice guy, actually I’ll tell you his name, he’s really really nice, he’s called [NAME REDACTED], he’s one ofhe’s the guy- he gives you a bit of an off-the-record, warts and all version of what’s gone on. And they’ve done this Gateshead Innovation Village where they’ve tried different schemes so they’re doing a test. And one of them [housing association] hasn’t tested a single product, how interesting. You know they’ve got, this year Great Places are putting 500 homes on the ground, Together Group 750, and not one of those is using offsite construction. And you know I was so surprised by that, I assumed everyone was testing stuff, but not at all. They’re all about to test stuff but it’s quite interesting... anyway. JP: No, it is interesting how you decided to go with the testing option instead of just putting in a big order. But I suppose it’s probably a better way of doing it before you do put in a big order. And then it goes back to that scale thing where you obviously don’t want to make a load of homes and then find out they don’t work for you I1: Well there’s that, but also, I think there’s something about not wanting to do pilots. We did want to pilot because we believed it was the right thing for this product, but generally I think there’s movement of ‘Don’t do pilots because you never get beyond the pilot’ you just kind of want to make it mainstream kind of thing, so I think I would- which is why 22 homes with Local Homes was a bit more than a pilot- it was a test but it wasn’t really a pilot. But I think where the product is established you could go to bigger numbers straight away, but you’re right, you wouldn’t want to do 400 straight off with a product you don’t know. You know you’d want to kind of 20 or 30 or 50 and then, you know.
63
Modular Homes: Why Not Sooner?
Anyway, it’s interesting that despite the fact everyone wanted to do this for years, there’s a lot of talk about it, we’re all gearing up you know, now– now is the moment you know it’s interesting how few people have actually tested it and done it, given our sector builds like thousands and thousands of homes a year. JP: Yeah, I have noticed that from recent things that there’s obviously a very few key names that keep on cropping up, like the Urban Splash and the Waugh Thistleton are the big dogs as it were at the moment who are pushing it with everyone else. But then Waugh Thistleton have been doing it for years so now they’ve got to the point where they can perfect it now from one pilot scheme. But it is interesting how a lot of people are jumping on without really knowing where to go- and then binning it off because obviously it doesn’t work because they haven’t tested it properly. I1: But then people are very nervous- people worry that houseowners won’t want to buy, but I don’t think anyone cares anymore. And then for social housing with offsite construction, banks won’t let allow you to use it as security, so you can’t borrow against them because they’re saying ‘well what if they all fail’, which is incredibly ridiculous, which you know we’re going to try and get Homes England to lobby against that because it’s just madness -well it’s not madness it’s just not helpful. JP: I think that’s about it from me, that was really helpful, and really good for the extra names as well. I1: Great, well good luck with your thing, and send me any thoughts you have about good products. JP: I will, don’t worry, thank you very much for your time. Goodbye. I1: Ok, bye. 7.2 - Interviewee 2
JP: Do you want to just start just by giving a brief overview of the project, and generally what it was? I2: So basically, this is a project for [CLIENT REDACTED], I think it may have been 2013, 2014 possibly. They had a really tight programme, so they turned around to us and said you’ve got six weeks to put a tender package together, and this is an extension to an existing halls of residence. So, the modular thing came from the university, they were like this seems like a good idea in order to get the programme moving really quickly. They’d done the calcs to say that given six weeks- if we got this tender package done and out for tender we could be on site for a certain time and then we’d have a very short programme in order for it to be finished for the students coming back. So, we’re talking very tight timescales which was why the modular route was looked at. So, we worked– and actually I walked past- I got a photo yesterday because I walked past the BAM7 - Walker Modular, I believe, were the people we were looking at using. Because I went past a residential development in Birmingham and they had lined up on the pavement outside all these 64
7.0 Appendix
bathroom pods which were going into a big student resi block. So anyway, I think it was Walker Modular who we were working with and we were looking at- I’ve just looked at their website, it just says bathroom pods, but I think at that time they were doing the whole room. So, we based this whole building on the maximum height which you could do which was three stories from memory. We set out all the rooms based on pods that could stack together and it fit quite well with what was there existing – in terms of setting out and the floor levels and things like that, although it was coming out- I think it was slightly higher then the one next door so we had a higher roof on one end of the building. So essentially what we did was we designed that, then it went out to tender and the contractors that came back all sort of said we’d rather do this traditionally out of blockwork and prefab- well not prefab, precast floors. JP: Did they give any reason for that really, was it justI2: I think really, it’s because they- I dunno- I think– I don’t want to be too sort of opinionated on it. But in my, from my point of view it was basically- it’s a cost thing, so the risk for them was- I think the issue you’ve got with modular buildings is if you’re gonna do a modular building like that, which is very much off the shelf, it all has to go up very quickly hasn’t it. So, in terms of the construction sequence things don’t really work in the same order that they would for a normal building. So, you’ve got like, if you’re stacking up all the pods, you’ve then got to work out how to get them all watertight- things like that straight away. So, there’s a risk to the contractor on that because they’ve got all these pods on site and then they’ve got to wrap- I mean for example on this building there’s a brickwork skin, so all we’re doing is wrapping it with a brickwork skin. Now brickwork skins take a long time to build, so obviously they took a look at it and thought: well ok, if we just do it floor-by-floor traditionally we can get the external skin on, we can even start putting windows in on the lower floors and things like that so- and then obviously- it’s probably more to do with how the contractors are set up and the supply chains they have in that- you’ll know very well that contractors have certain companies they like to use, and they use them on jobs repeatedly because they get the best price from them that way, so they know that they can go to so-and-so bricklayer and so-and-so blockwork layer and they’ll do a good job, they’ll trust them and they’ll do it for nothing basically and then they’re gonna get a really good profit margin. Now, they’ll look at a modular building, they’ve never worked with a modular company before for example, so there’s a risk there where they don’t know how well that’s gonna work from a design point of view. So, I think that’s really the fear of the unknown really. So basically, they came back, from memory we had five or six contractors come back. We went with [CONTRACTOR REDACTED]. So at that point, when they came on board, we sort of agreed with them in 65
Modular Homes: Why Not Sooner?
tender negotiation period, which is usually a sort of VE8 period isn’t it to try and get the prices down, we agreed with them that they’d only do bathroom pods. So we went ahead basically with that and then I think that- we started going through the process of doing the final design work for the bathroom pods, and again I think the contractors were getting a bit nervous about it because they- basically they had all these trades on site doing they, so they had somebody there doing plasterboard lining, doing dry partitioning, you’ve got somebody doing the partitioning, and they’re like well, you know if we add X cost to their contract to get this bathroom set out then it’s all good. Because the other thing with the- and this is probably more to do with the building, and this was something I was thinking about yesterday, so the interesting thing yesterday was they had all these bathroom pods lined up on the side of the road, and they were obviously craned in to reach each floor. Now with the site we were working on it was very restricted, so essentially if you think about the way a building is built, you’ve got the first floor built and set out– at that point, because the corridors are so tight, we were working on 1100 [mm] corridors, which is like minimum- I don’t even know if that’s– it might even be below building regs, but we agreed because there was such short corridors, and from a Part M point of view we didn’t have any wheelchair users using those rooms basically, so we had special DDA type rooms on the ground floor around the whole site, so it was a bit of a sort of variation to the building regs on that. So if you think about it, they have to then crane those modular units in before they lay the first floor slab because there’s no sort of way of rolling them in, whereas this site I looked at yesterday, which is a multi-storey student resi scheme next to Lancaster Circus in Birmingham, they’d obviously set up the job where they obviously can just crane these in one-by-one and there’s enough room to do that basically. Basically, if you’re doing a modular building you need to change your programme for everything, because you’ve got to do a lot of design work up front to get all that agreed with the client, get all the finishes agreed with the client, then get all the specifications of the sanitary ware and things like that all sorted very early on in the job, which is quite difficult depending on which client you’re working with and then of course the lead-in of them making the pods, which isn’t going to be that quick, but the sort of rapid thing is that they can go up on site very quickly, but actually they don’t necessarily build them that quickly. But obviously you’ve got the guarantee, the high-quality finish I suppose that’s the other thing. So with this particular project, yeah, it was a question of price, because they could just use the same people, so obviously we went away from doing even the bathroom pods eventually when we were on site because they were like well we can get these people to do it and we were like ok we’ll spec everything separately and we’ll do it that way basically, which I think actually- the thing I thought after the job, I thought it did get very complicated for all of them. Because the problem was, we got these really tiny bathroom pods you know, they were designed as a bathroom pod and the modular units are perfect, because everything’s sort of plumbed in isn’t it. But we had like a return with a tiny sink in which was 66
7.0 Appendix
probably like 600 [mm] across – you can imagine like a recess in a wall basically. So then on site that was really difficult to actually build correctly and get the quality of the manufacture on site good, because what we found by then was in all those bathrooms they’re a complete mess because there wasn’t enough room for a plasterer to do the plastering and things like that so, do you see what I mean. You were getting to such a small- it was like micro architecture isn’t it, because you know with a pod, which would have been plumbed in on the one side, on the corridor side, and then you’ve got all your inlets you know, all your drainage points and things like that, and that goes to a sink on the other side of the pod, and then they had to plumb that all in manually on site, and actually I think that caused them more problems than they thought. So, I think the lesson learnt there I think they should have done a pod there really, but it was just the case that it didn’t really lend itself in the way that the programme was running. So, the problem was we designed it as a modular pod, but then if you’re gonna be building it out as a sort of on-site thing it doesn’t really work, so that’s a lesson learnt from an architecture point of view. JP: So, was there a lot of work for you guys, as the architects to modify everything to make it work as a wet construction? I2: No not really to be honest because we just had to- we just set it out exactly the same, but I think in hindsight we probably should have made them slightly bigger, because its not quite- we modelled them on the minimum shower size because this was something like, was it 700 [mm] across or something like that for a shower tray and you sort of think that actually, if that was a like a moulded sort of bathroom pod, that’s not really a problem is it. But when you’ve got to put in a shower tray that’s that small, and then you’ve got a shower door that you’ve got to put in, and then you’ve got a toilet that’s next to it and then you’ve got a sink, it just sort of– it becomes very difficult managing that sort of small space on site anyway. JP: How did the client feel about the change, did they just see it as – essentially was there a cost change from the contractor? I2: I don’t think they offered a saving- I think they did actually, I think they offered a saving from memory, they offered a saving to the client to do it basically. It wasn’t a huge amount, but its difficult to know if whether they got better profit out of it or not really. But yeah, it was almost like a value engineering option given to the client. Because they’re [Modular Units] not cheap, and you probably know that from modular buildings, yeah its not a cheap way of doing it and that’s why the contractors did a traditional method of building, it works quite well. But I think you know with that sort of scale building it didn’t really lend itself to it, that type of thing. But if you’re doing a very large- I think the bigger it gets the more it makes sense really yeah.
67
Modular Homes: Why Not Sooner?
JP: And I suppose from your point of view was this the first time you’d done a modular system, what were the challenges you faced as an architect getting used to modular? I2: Yeah, I mean it was fairly straightforward really, I don’t remember it being anything too untoward, the most complicated one was when we were looking at the rooms, the four rooms. We had to have a lot of meetings with the company to sort of work out, get our heads around the limitations of the systems, so these are things like how high can you go, how wide rooms can be, because they have maximum things like they have maximum heights, maximum numbers that they can stack on top so that was a bit of a new thing for me. It was the first time I’d worked on a modular building then and I haven’t really come across anything since then, but I haven’t really done much residential stuff since then, so there’s not really anything that’s lent itself to it. JP: From that then, do you see yourself working on more modular projects in the future? I2: Yeah, I think it will become more common, I’d say it was a bit of an early adoption sort of thing there really, because I don’t think it was really used a huge amount before then. I think at the moment it’s more and more common especially with the amount of residential work that’s going on at the moment. Looking at this building in Birmingham, it was a big concrete frame and they just had all the bathroom pods prefabbed, but it didn’t look like the rooms were prefabbed or anything it was literally just a bathroom pod. But I think when you’re doing it on such a large scale it works out really well to be honest. And also, for the client, because they get the guarantee of the finish internally which is a massive thing really. So they’ll [the manufacturer] do a mock-up and they’ll go see it and they’ll be like yeah this is exactly what every room will look like, which is something you don’t really get do you these days on site, but nah, I definitely see it becoming more and more common, but yeah maybe limited to the residential sector. I don’t know whether you’ve come across any other sort of uses of modular. JP: To be honest not really, because you have unique things that you need them to use multiple times, which is why it’s just resis really, unless it’s kind of shipping container architecture style things which are used a bit more often. I2: You might get some prisons JP: Yeah it is used in prisons I2: Yeah, anything that’s repetitive like that, hotels, I guess. In fact, hotels is one and actually I don’t know if there’s anyone here, because there’s a project in Birmingham that’s prefab modular bedroom units that are stacked on top of each other. And actually we, I don’t know who worked on that in the office because it was a long time ago, but all we did was actually I think the Travelodge designed the whole building, and actually all we designed was the façade for it, literally the treatment on the outside, but everything else 68
7.0 Appendix
was done- it was literally just stacked up on site. So, I’d have a look into hotels because I think that’s really common. Because I remember we were looking at another one somewhere else in Birmingham, another hotel that was a prefab type system. I’ve also stopped in a few myself -there’s one in Manchester I stopped in, where was it, it was an Ibis Budget in Manchester – they had a bathroom pod. JP: Yeah, I’m seeing bathroom pods are pretty widespread now. You also talked about the reason the client went for modular in the first place was the tight programme. How much of a knock-on, if any, did the switch from modular to normal construction have on the building? I2: Well I think in terms of -I said about the quality issues. It didn’t really have an effect on the programme because I think the difference was they could get on with it straight away, whereas they would have to had to have waited for the modular units to be built and done out, and then constructed and then brought to site, so yeah it didn’t affect the programme, which is strange, and also I think it was cheaper, which is strange isn’t it -but at that time maybe it was, I think maybe the margins wouldn’t be -I think the margins on cost and programme would be a lot closer now definitely, and that’s because I imagine someone like Walker Modular would be that they’d be doing these every day. In fact, their website says bathroom pods to Hilton Hotels, Travelodge’s, and Whitbread; trusted industry leaders -have you managed to speak with them? JP: No, I haven’t actually I2: It would be worth asking them, in fact you might just be able to look on Companies House, look at their accounts, see how much money they’re turning over each year, see how much its increased from five years ago. That would be an interesting one to put in your dissertation. 7.3 - Interviewee 3
JP: So, we’ll just start off with a general description of the project really, of the [Gateshead] Innovation Village as it were I3: So, the Innovation Village is a development of 41 houses in Gateshead, where we are looking to, I guess, try out offsite construction technologies alongside some different electric heating solutions and smart technology. JP: What made you start the project, was it solely to look at combating the housing crisis, or were there other reasons behind starting it? I3: It was started predominantly as a result of, you know, we can see challenges in achieving the sort of volumes of new housing that are required, we’ve got quite an ambitious development programme which
69
Modular Homes: Why Not Sooner?
sees us build 10,000 new homes over five years – we’re in year three of that at the moment- and offsite construction was seen as one of the ways that we could help increase our volumes- are going up year on year and so offsite construction was seen as one of the ways we might be able to achieve that by effectively delivering projects more quickly and also I guess delivering projects in a different way to using the traditional construction route. So, I guess the project came about because we wanted to try out offsite construction. It came about specifically in Gateshead because we had a piece of land in Gateshead which was originally going to be phase 2 of an Ikea housing project called Boklok, and phase 1 of that project didn’t go that well -that happened about 10 years ago just prior to the housing crash after the financial crisis. So the piece of land stood empty for about 10 years, it was under our ownership and so we had the maintenance cost of keeping the grass cut and taking away fly-tipped items, and people kept tethering horses there- we ended up with big fences round it and so we really wanted to develop that piece of land, but we couldn’t make it work financially for us building traditional houses because it’s not in a particularly affluent area, so the market value and rental values are low, but the land was contaminated and so the build costs were high- trying to make that financial viability model work for a traditional project, we just couldn’t make it stack up. So the idea came about that how about we do it as an offsite construction project and approach Homes England as our grant funder to see if they would give us additional funds because of it being an innovation project that could be for the benefit of the wider housing sector. And so, with the additional grant money that we were able to attract that enabled us to offset the increased build cost associated with offsite construction, but also offset the high cost of remediating the contaminated land. JP: It says on the website there were 5 modular systems you tried as well as the traditional ones? I3: So, there’s 5 different construction types, there’s 3 different volumetric modular solutions, and then there’s a panellised light gauge steel solution and a panelised aerated concrete block solution. So whether you would describe the light gauge steel and concrete as modular I guess depends on your definition of modular construction –that does vary. JP: Yeah, it’s been an issue I’ve been struggling with I3: It’s a bit of a loose term isn’t it – it means different things to different people JP: What was the reason for trying so many systems, and what made you pick these systems in particular? 70
7.0 Appendix
I3: So I guess we looked at the market at the time, this was just over two years ago- about June / July 2017 we started the project. And we looked at the marketplace and what was out there and we effectively did a sourcing exercise looking at things like from a design perspective what could you achieve in terms of design flexibility in the different systems, how much did they cost, could you get building warranties on them, could you- were they mortgageable, that sort of- all of those sorts of things. And so, we did this exercise and picked- actually through the initial exercise picked two volumetric companies, and two alternative MMC9 technologies. The thinking behind providing or trying both is that we were well aware that the volumetric stuff had limitations in terms of accessibility to certain sites, certain sites that are up very little country roads, or particularly tight- would require deliveries through particularly tight streets- the volumetric doesn’t work. And also, there’s some design limitations around you having to size your units in accordance with what you can get on the back of a lorry; those things obviously don’t exist with the panellised, so we decided to try a mixture of both. Like I say we picked two volumetric originally and two others and then probably about three months after we’d done that selection exercise one of the volumetric companies, a company called SIG was bought by Urban Splash and they backed out of the project. So we then replaced 10 units that were meant to be supplied by SIG with 8 units by a company called Premier Modular, and 2 units supplied by a very small start-up company called Simply Modular. So that’s kind of why we were trying to try different things, rather than almost nail all our colours to one particular solution and just build out the site with that. Doing the five different construction types on one site has presented its own unique challenges, I guess that you probably wouldn’t ever get on a real- on a typical project, and because of that complexity, particularly around the construction side of things we appointed a principal contractor to manage the project for us, so we used ENGIE to act as a principal contractor and actually all the modular companies are suppliers into them, and that was mainly around coordinating the site works and things because we couldn’t- most of the, in fact all of the different offsite technologies all require a crane for construction and we couldn’t have five different cranes all turn up at the same time and building their units so there was obviously a sequencing and a logistical exercise which ENGIE have kind of managed and coordinated for us. JP: Following on from that then, what were the challenges that you experienced with some of these systems, whether it’s specific issues with some of the systems, or just overall general issues? I3: What have been the challenges- I mean we’re not totally finished yet, we’re almost there but we’re not completely finished yet, the last units are supposed to be handed over next week. So, we’ve had challenges around adherence to the programme by the modular suppliers, so, and because there was a planned and sequenced order made the project more difficult to deliver when you expect some units to turn up at a certain time and they don’t hit their slot that has knock-ons to other parts which- I guess we 71
Modular Homes: Why Not Sooner?
found- we had more work on site on the volumetric units than we had anticipated, so you know the whole concept of the volumetric units is that everything’s done in the factory and they deliver and just assemble it, just kind of stick it together on the site; the reality has been with two of the three providers there’s actually been a lot of on-site works gone on, weeks and weeks of on-site works. JP: Is that within the buildings themselves or just general site works? I3: No no- no, to the buildings. So, external claddings of units with the brick slips, all of that has ended up being done on-site, and of the lot of the internal fit-out as well has ended up happening on-site. So, the degree that you would have expected to be done off-site hasn’t, wasn’t exactly in-line with our expectations. Now, some of that is about us forcing a- to hit a time slot, so effectively delivering earlier than they may have chosen to, but I think some of it is also about a fairly immature supply chain who- that hasn’t done a huge amount of these projects and is still learning. JP: Yeah, as you were saying both were pretty small companies weren’t you, like two of them anyway I3: Simply Modular is a pretty small company, Ilke Homes is a reasonably sized company, but fairly new. Premier Modular are a fairly large established company albeit not in volumetric modular housing so you know they typically made Portacabins, things like those little Timpson units you sometimes see in front of Tescos, those like little modular shops things that they plop down in a car park, so that type of thing, and they’ve got lots of experience of that, but not for much around low density modular housing, so there were some learnings around that. The co-ordination required I think is different to a traditional project, so things like co-ordinating the mechanical and electrical design work has been difficult, partly difficult because we’re doing more complex M&E solutions in the units, but the kind of trying to make sure that the modular companies do what you want them to do when they’re not doing it on the site has not always been easy for ENGIE or for us as the client. I think there’s a lot more upfront design activity in an offsite [construction project] than there is in a traditional one where design work is taken to a point, then work starts on site, and there’s a bit of parallel activity- design activity going on while some of the site works is going on and it’s done I guess a little bit more on the hoof, whereas in the offsite projects, yeah, a lot of that design work, and a lot of that decision making is done earlier, so trying to I guess, structure our own processes as client, and getting our principal contractor to work in a different way has proved challenging and I guess we wouldn’t necessarily replicate exactly what we’ve done on this project again, if we’re doing it again - we’ve all learnt something about it all. In terms of some of the products, so with the volumetric ones, actually we learnt there’s quite a lot of limitations, so I think what was attractive to us about the panellised systems is they’re- with them there was almost an ultimate level of design flexibility, so where we wanted interesting shaped roofs, unusual72
7.0 Appendix
like corner windows and things like that, they could be achieved in the light steel frame and the concrete but most of them couldn’t be achieved in the volumetric, well they couldn’t be economically achieved, which I guess makes us worry a little bit about when- if we were doing a whole development of one particular type, how we would meet the planning requirements of a ‘well-planned’ housing development, rather than you know some ‘cookie-cutter’ houses that all look identical, which probably wouldn’t be acceptable from a planning perspective. So you know we would normally make a housing development a mixture of house types, with different orientations and corner treatments to make it meet the planner’s requirements and that’s I think more challenging with the volumetric because of those design limitations. Not impossible to achieve, but potentially more difficult and if you wanted to address that by doing some houses in volumetric and other houses either traditionally, or in a traditional technology, you potentially lose the timing advantage of a totally volumetric site. JP: That’s something not many people have brought up which is quite interesting becauseI3: Because obviously you tend to go at- the site will run at pace of the slowest construction so if you’re building I don’t know at the entrance to a particular development some interesting corner features in a different house, then the whole development is then, in terms of pre-lims [sic] and all that side of things, the length that it will take to build that out will be governed by the traditional ones or the different ones that you’re building those interesting corner units out of. I guess the other thing we’ve learnt- the downside that we’ve learnt around the panellised systems were around, fundamentally around the fact that with those technologies you’re effectively replacing the breeze block part of a traditionally constructed house with something that goes up more quickly and gets you to a watertight stage more quickly, but then you still need all of the traditional trades to do the brick outer skin, and all the internal fitouts, and so if you’re looking at offsite construction because of skill shortages, then those technologies probably not gonna help- be a huge benefit. That said, we did see some timing benefits, some programme benefits from the speed of which we got to that watertight stage, and so we do think there is a time saving over a traditionally constructed house, we just haven’t got to- because we haven’t quite finished we haven’t done that detailed analysis to work out exactly what that time saving is yet. We also found with- particularly where the light steel frame product was concerned that the plaster boarders didn’t like working with it, so actually in one sense moving to a different technology gave you a different trade skills problem. So it wasn’t that we couldn’t get boarders, but plaster boarders are paid by the amount of board that they fit and to fit- to board out the light steel frame houses was slower than it would be in a traditional one and had to be done by hand rather than with a gun fed with the fixings, and so we had plaster boarders who refused to work with it because of that, because they could get better pay and work elsewhere. 73
Modular Homes: Why Not Sooner?
JP: Following on from that then, what are the kind of general- because obviously the main thing people cite is the costings of volumetric housing, have you noticed a massive cost difference between the modular systems and the traditional construction? I3: I guess on this site there is a big difference. Now, and I would say using a kind of broad generalisation, I would say it’s around 25%, 20-25% more. However, I guess we’ve bought units in pretty low volumes, and we’re comparing them to traditionally constructed units in a part of the country that’s probably the cheapest to build traditionally. So whilst that differential might always exist when you’re building in Tyneside, we know, because we’re a national developer, we know the cost difference of the traditionally constructed housing that we’re building in the South East is more than 25% more expensive and soand actually the volumetric stuff obviously doesn’t change because it’s still built in the same factory. So we do think that that cost differential will- won’t be so significant elsewhere, and obviously all of these companies at the moment haven’t got a great handle on the real cost of things; they’re buying their materials in small volumes, they haven’t got their manufacturing processes ironed out, or really efficiently planned, and so I think a combination of their costs coming down, and maybe some selectiveness around geography means that- we don’t think that it will be prohibitive in all parts of the country. JP: Something else you alluded to on your website was the public’s perception of what they actually think modular is. Is that something you’ve felts changed from working with this village- have you had the general public visit? I3: We’ve had a lot- something like 700 people visit the site during the construction. I don’t necessarily think you would call them the general public though because they’ve largely been industry- housing sector people or local authority people or building industry people. I guess the bit around the public perception, we haven’t yet tested. But I would challenge anyone to walk onto the site now and identify it as anything other than a new housing site, I don’t think you can- you can’t tell that they’ve been built using different construction methods – you can’t really tell the differences- there are design differences between various units on the site, but you couldn’t easily spot that those four are one type, and this- those three are another type. And it hasn’t in terms of applications, we’ve had a huge number of applications from people who want to live there. JP: Going back to what you said at the start about the Boklok scheme, that’s coming back to the UK now. If you worked on the first phase, do you know what was so unsuccessful about it I3: I don’t- it was before I was with the organisation, and actually there’s very few people left in the organisation who were involved. I think the problems with the project weren’t really to do with the Boklok technology, the problems with the project were around the main contractor going bust during the project and the housing crisis of the financial crisis hitting at the wrong time, rather than it being specifically about the project. I think the designs were unusual as well; the internal layouts are quite Scandinavian 74
7.0 Appendix
which weren’t to everyone’s taste. But I think fundamentally it’s a panellised timber frame solution thatI mean as I mentioned we’re a national housebuilder, and the vast majority of what we’re building in Scotland is built out of panellised timber frame because in Scotland that’s the norm. So we are, as an organisation, still building with that technology. JP: I suppose, going forward as a housing group, is this modular one of the main avenues you think that you’re gonna take as an organisation? I3: I think for the moment it will remain a minority avenue rather than a main- a supplementary way rather than the main way. We are doing further schemes, so we’re actually on site at the moment with a scheme in Cumbria, where we’re demolishing existing poor-quality stock and replacing it with Ilke volumetric modular units - we’re doing another one in Kent, which is a volumetric timber frame solution. So it will continue to be part of our development programme, but I think- you know actually there’s not the capacity in the market to do all of everybody’s development pipeline. I think it will, over time become a slightly bigger part of our programme, but I guess it remains to be seen as to how big it turns out to be. JP: Do you know what percentage of your company- well what part of new build is modular? I3: So- now I’ve worked this out for a different- rather than you sit while I try to- I’ll email you with that, rather than you sit while I trawl through emails because I did a survey where I had to work that out. It’s not a very big percentage. I guess it depends on, again, going back to an earlier conversation, depends on what you describe as modular. JP: In this case I’d go for volumetric I3: Ok fine, well I will work that out- how many- well I think we’re talking about- something in the order of, it’s gonna be less than 10%, probably less than 5%. Yeah but let me dig out the figure and I’ll pop you a note with that on. JP: Well I think that’s all the main questions I had really. Thank you for your time today, it’s been a great help. I3: Not a problem, like I said I’ll pop that information in- and as you write your report and you think, oh I wish I’d asked that, then just give me a shout. JP: Brilliant, thank you very much I3: No problem, cheers, all the best. 75
Modular Homes: Why Not Sooner?
REFERENCES
Panellised system supplier Wikihouse is an open source panellised building platform for homes 3 Report by the interviewee’s association on relative costs of using each system 4 Interviewee gave figures for both systems tested, however wanted them to remain confidential. With these figures, the Local Homes system was comparable to traditional construction. 5 Design and Build contract 6 Sheffield Insulations Group plc 7 Building contractor BAM's site in Birmingham 8 Value Engineering 9 Modern Methods of Construction 1 2
76