Primary researchModern methods ofconstructionViews from the industryNF70NHBC FoundationNHBC HouseDavy AvenueKnowlhillMilton KeynesMK5 8FPTel: 0344 633 1000Email: info@nhbcfoundation.orgWeb: www.nhbcfoundation.orgTwitter: @nhbcfoundationAcknowledgmentsThis research was carried out by Lychgate Projects Ltd.We would like to gratefully acknowledge the industry representatives whoattended the focus groups and took part in the telephone surveys.© NHBC Foundation. June 2016Published by IHS BRE Press on behalf … Continue reading “NF70 NHBC Foundation | My Assignment Tutor”
Primary researchModern methods ofconstructionViews from the industryNF70NHBC FoundationNHBC HouseDavy AvenueKnowlhillMilton KeynesMK5 8FPTel: 0344 633 1000Email: info@nhbcfoundation.orgWeb: www.nhbcfoundation.orgTwitter: @nhbcfoundationAcknowledgmentsThis research was carried out by Lychgate Projects Ltd.We would like to gratefully acknowledge the industry representatives whoattended the focus groups and took part in the telephone surveys.© NHBC Foundation. June 2016Published by IHS BRE Press on behalf of the NHBC FoundationISBN 978-1-84806-444-7NF70Primary research June 2016Modern methods ofconstructionViews from the industryNF70ii NHBC Foundation Modern methods of constructionThe NHBC FoundationThe NHBC Foundation, established in 2006, provides high-quality researchand practical guidance to support the house-building industry as it addressesthe challenges of delivering 21st-century new homes. To date, it has published70 reports on a wide variety of topics, including the sustainability agenda,homeowner issues and risk management.The NHBC Foundation is also involved in a programme of positive engagementwith the government, academics and other key stakeholders, focusing on thecurrent and pressing issues relevant to house building.To find out more about the NHBC Foundation, please visit www.nhbcfoundation.org.If you have feedback or suggestions for new areas of research, please contactinfo@nhbcfoundation.org.NHBC is the standard-setting body and leading warranty and insurance providerfor new homes in the UK, providing risk management services to the housebuilding and wider construction industry. All profits are reinvested in researchand work to improve the construction standard of new homes for the benefit ofhomeowners. NHBC is independent of the government and house builders. Tofind out more about the NHBC, please visit www.nhbc.co.uk.The NHBC Foundation Expert PanelThe NHBC Foundation’s research programme is guided by the followingpanel of senior representatives from government and industry:Rt. Hon. Nick RaynsfordChairman of the NHBC Foundationand Expert PanelJane BriginshawDesign and SustainabilityConsultant, Jane Briginshaw andAssociatesAndrew BurkePolicy Officer, National HousingFederation (retired)Richard CookHead of Residential Development,Lend LeaseClaire Curtis-ThomasChief Executive,British Board of AgrémentHywel DaviesTechnical Director,Chartered Institution of BuildingServices Engineers (CIBSE)Andrew DayDirector, Architecture, Design& Sustainability – New Homesand Communities, CountrysideProperties (UK) LtdRussell DennessGroup Chief Executive,Croudace Homes GroupMichael FinnDesign and Technical Director,Barratt Developments plcCliff FudgeTechnical Director, H+H UK LtdRichard HardyManaging Director, BRE GlobalRichard HarralHead of Technical Policy,Building Regulation andStandards Division, Departmentfor Communities and LocalGovernmentRichard HillChief Executive,Spectrum Housing GroupNeil JeffersonDirector, NHBCRod MacEachraneDirector, NHBC (retired)Robin Nicholson CBESenior Partner, Cullinan StudioTadj OreszczynDirector, The Bartlett School ofEnvironment, Energy and ResourcesGeoff PearceExecutive Director of Regenerationand Development,Swan Housing AssociationMike QuintonChief Executive, NHBCHelen SaundersGroup Marketing Director,Crest Nicholson plcSteve TurnerHead of Communications,Home Builders FederationAndy von BradskyConsultant, PRPKarl WhitemanDivisional Managing Director,Berkeley HomesTony WoodwardManaging Director,Kingerlee HomesNeil SmithHead of Research and Innovation,NHBC, and Secretary to theExpert PanelNHBC Foundation Modern methods of construction iiiContentsForeword v1 Key findings 12 Background and introduction 33 Methodology 53.1 Stages 53.2 Weighting of data 64 Definition of modern methods of construction 75 Use and consideration of MMC 95.1 NHBC statistics on construction type 95.2 Use and consideration of different types of MMC 105.3 Types of panelised systems used 135.4 Types of off-site manufactured sub-assemblies and components used 145.5 Where are decisions made about the construction method? 155.6 Willingness to innovate 156 Factors driving consideration of MMC and 17experiences in practice6.1 Main reasons for considering MMC 176.2 Benefits of MMC in practice 186.3 Experiences of volumetric construction and pods 207 Concerns and barriers to using volumetric construction 238 The future for MMC 259 Factors to be addressed for increased use of MMC 33Appendix A: Focus group attendees 35Appendix B: Weighting of results 36References 37Further reading 37iv NHBC Foundation Modern methods of constructionNHBC Foundation Modern methods of construction vForewordThe very mention of the phrase ‘modern methods of construction’ (MMC) hastended, for more than half a century, to generate heated debate and conflictingreactions from those involved in the building industry.In the aftermath of the Second World War the need for a rapid expansionof housing output provided a strong impetus for innovation, and this ledto extensive applications of new systems and technologies. However, apreoccupation with quantity rather than quality, coupled with a failure to thinkthrough the full implications of some of the new approaches, contributed to anumber of highly publicised failures, which in turn prompted a reversion to moretraditional house-building techniques.More recently, around the turn of the new millennium, and partly inspired by theEgan Report Rethinking construction[1], interest revived in the potential of newmethods, including the wider use of off-site prefabrication, to deliver efficiencygains and improve quality. But once again the high hopes invested in MMC, as ameans of delivering transformational change to the house-building industry, havenot been realised on the scale anticipated by their champions.Yet for all the reservations expressed by the sceptics, and the clear lack ofenthusiasm in the bulk of the industry for the more radical and far-reachingmanifestations of MMC, house builders have been making extensive use of avariety of innovative approaches, including components assembled off-site.Indeed in a context where once again a rapid expansion of output is required, butwhere the industry is facing severe skills shortages, it would be surprising if therewas not a keen interest in exploring new methods with the capacity to improveboth quality and efficiency.This new research from the NHBC Foundation explores attitudes towards MMCacross the industry. It records the degree to which different methods and systemshave been adopted and assesses the appetite for more extensive applicationof specific approaches. It finds an industry, which, while cautious about overcommitment, is nevertheless embracing MMC in many guises, and remains readyto explore new options and innovations.The research has depended on the participation of a number of house buildersand housing associations whose contributions are gratefully acknowledged.I hope that the findings will be of interest and use to many organisations andpeople involved in house building, and will stimulate discussion on the scope formore effective innovation across the industry.Rt. Hon. Nick RaynsfordChairman, NHBC Foundationvi NHBC Foundation Modern methods of constructionNHBC Foundation Modern methods of construction 1Alternative forms or modern methods of construction (MMC) have a longhistory in the UK. In the post-war period much use was made of a variety ofinnovative house-building systems and from time-to-time since then, there havebeen surges in interest. An industry survey, reported in this publication, wascarried out at the end of 2015. It aimed to establish current attitudes to MMCamongst the larger house builders and housing associations.Key findings were as follows:1. The majority of the organisations surveyed have made use of MMC: 98% oflarge and medium-sized house builders and housing associations have usedor considered at least one form of MMC in the last 3 years.2. The most widely-adopted form of MMC is sub-assemblies and componentswith two-thirds having used them for at least one home during 2015. Thiscategory includes items such as door sets, timber I-beams, prefabricatedchimneys and prefabricated dormers.3. The second most popular form of MMC is panelised systems (eg timberand steel frame), which was used by 42% of respondents during 2015 for atleast one home. In the lead was timber frame which, according to NHBCregistration statistics for 2015, accounts for 15% of UK housing output. InScotland, where timber frame is used for three-quarters of new homes, it isnot regarded as a modern method.4. Only limited use is being made of volumetric construction (large modulesfully fitted out on-site) and pods (room-sized modules normally bathroomsor kitchens) with 6% and 7% of organisations having used these methodsrespectively one or more times in 2015. Use tends to be concentrated inapartment buildings in London and the South East.1 Key findingsKey findings2 NHBC Foundation Modern methods of construction5. The majority of organisations surveyed consider themselves to be ‘lateadopters’ or ‘followers’ of volumetric construction, pod and panelisedforms of MMC, watching the success of others before making the decisionto move away from conventional cavity masonry construction. Only 10%of house builders considered themselves to be ‘market leaders’, leadinginnovation.6. One of the key attractions driving the use of MMC is the perceived ability tobuild more quickly. While house builders reported that faster constructionis being realised in practice, housing associations were less convinced; theydid, however, believe that a weathertight envelope was achieved quickerwith the use of MMC.7. It was also felt widely that MMC would have a role to play in improving thequality of construction and overcoming current shortages in the availabilityof skilled labour. For those already using MMC these perceived advantageswere being realised in practice.8. There is some evidence of MMC leading to a reduction in costs andimproved profitability, with 44% of house builders and 27% of housingassociations pointing to benefits such as reduced preliminary costs,improved cash flow and faster sales revenues.9. Most participants expect the role of MMC to grow or remain static over thenext 3 years; only 3% expected it to decline. Over half expected the use ofpanelised systems, in particular, to increase during that period. Drivers toincreased use include overcoming skills shortages, faster build, increasingoutput and improving build quality.10. If there is to be greater use of pods and full volumetric construction, riskswithin the supply chain need to be addressed. There are concerns aboutthe size, quality and capacity of suppliers and their ability to sustain highvolume output. Other issues include a need to build-in the ability toprovide bespoke designs and interiors and overcome the constraints ofstandardisation, the need for an early design freeze and transport logistics.NHBC Foundation Modern methods of construction 3The history of innovation in construction in the UK is long, dating back tobefore the Second World War, but comparisons with the current housingmarket challenges are striking. In the post-war period, there was a housingcrisis with over 200,000 homes estimated to be required quickly; PrimeMinisters were heavily involved setting up cross-party committees to examinesolutions and Government programmes were being rolled out to build ‘newtechnology’ homes. In 1944 this was known as the EFM (emergency factorymade) programme which, despite a good start, eventually delivered 153,000‘temporary’ prefabricated homes. Alongside these were ‘permanent’ nontraditional homes of which almost 450,000 were built in the decade followingthe war.More recently the need to increase off-site construction in the housingsector, and the construction industry generally, was discussed in the LathamReport, Constructing the team[2], Joint review of procurement and contractualarrangements in the United Kingdom construction industry published in 1994,and the Egan Report Rethinking construction[1] published in 1998. By drawing onexperiences of other industries such as manufacturing, these reports sought toidentify how to improve efficiency, reduce waste and make the industry moreresponsive to customer needs.Currently we still see an industry that has largely continued to use masonrycavity wall construction for low-rise residential new build. The success of off-sitemanufactured homes seen in other parts of the world, such as Scandinavia andJapan, has not generally been replicated in volume in the UK.2 Background andintroductionBackground and introduction4 NHBC Foundation Modern methods of constructionThe pressures in today’s housing market are:■■ high customer demand with shortfalls in supply■■ shortages of skilled labour and materials■■ a drive for construction speed■■ achieving high quality and energy performance■■ the elimination of waste.These pressures have echoes of past challenges which could be expected toencourage use of off-site methods, now referred to as MMC. So how is theindustry responding?To examine current attitudes, policies and use of MMC and its prospects forthe future, the NHBC Foundation commissioned research amongst large andmedium-sized house builders and large and medium-sized housing associationsin the private and social residential sectors.The research set out to answer the following questions:■■ the extent to which organisations are embracing or considering MMC■■ factors which are driving their interest■■ reasons for using or rejecting MMC■■ benefits and drawbacks experienced in use■■ views on the extent to which MMC will contribute to a significant increase inbuild volumes to meet demand■■ expectations for future use of MMC and factors which could lead to anincrease in use.The intention of this report is to help understand current attitudes towardsMMC amongst those responsible for delivering new homes and to understandwhether it is being adopted to the benefit of the industry.NHBC Foundation Modern methods of construction 5The research focused on large and medium-sized house builders and housingassociations. Those participating accounted for just over 45,000 homes or 30%of NHBC new home registrations in 2015.The research was conducted in two phases, involving both qualitative andquantitative methodologies.3.1 StagesStage 1Focus groups, each lasting 2½ hours, were held in London, Glasgow andBirmingham. These were attended by 29 people in total, representing a mix ofhouse-building companies and housing associations. Attendees are listed inAppendix A.Stage 2Stage 1 results informed the questionnaire design for stage 2, the quantitativestage, which involved 135 interviews by telephone (Table 1). Three-quarterswere with regional and head offices of large and medium-sized house buildersand one-quarter with housing associations.Interviews, lasting an average of 24 minutes each, were conducted with avariety of senior people, including house builders’ technical directors, technicalmanagers, construction directors, construction managers and housingassociation development directors and managers.3 MethodologyMethodology6 NHBC Foundation Modern methods of constructionTable 1 Telephone interview programme No. interviewsHouse builders– Large national house builders*– Medium, regional house builders†6139Housing associations35Total135London and the South East49Rest of England and Wales73Scotland13 * Building over 1,000 units a year nationally.† Building 200 to 1,000 units a year nationally.Interviews were spread geographically and some results have been analysed inaccordance with the geographical classification shown in Table 1.3.2 Weighting of dataThis survey was conducted to be as representative as possible of the large andmedium-sized house builders building 200 or more homes a year, and largeand medium-sized housing associations that have a new homes developmentprogramme.In aggregating data from these groups, to arrive at an ‘all’ figure for some ofthe results quoted in this report, a weighting factor has been applied to eachgroup. This ensures that their answers are reflected in the all or total figures inproportion to the number of new homes each group built in 2015. More detailsare provided in Appendix B.NHBC Foundation Modern methods of construction 7The term modern methods of construction (MMC) embraces a number ofapproaches involving off-site manufacture or assembly. The definitions of MMChave varied over the years but for the purposes of this research for the purposesof this research, the following types of MMC were used (illustrated further inFigure 1):■■ volumetric construction■■ pods■■ panelised systems■■ sub-assemblies and components■■ site-based MMC.The types of MMC used in the research are based on those used by BRE in theNHBC Foundation report A guide to modern methods of construction[3]. Thisclassification also includes innovative on-site methods designed to improveefficiency and/or reduce waste, such as thin joint blockwork.The definitions and appropriate images were shown to participants as the basisfor questions about approaches they had used, and the extent of their use.4 Definition of modernmethods of constructionDefinition of modern methods of construction8 NHBC Foundation Modern methods of constructionFigure 1 Types of MMCThere was some discussion in the focus groups about use of the term MMCand its application to approaches which have been in use for some time. Forexample, Scotland has a long tradition of building in timber frame, where itaccounts for the majority of residential new build; those in the focus group didnot feel that timber frame should therefore be described as a ‘modern’ method.Types of MMC5. Site-based MMCInnovative methodsof construction usedon-site. They includethin joint blockwork andinsulated formwork4. Sub-assemblies andcomponentsLarger componentsincorporated intonew homes. Theyinclude roof and floorcassettes, prefabricatedchimneys, porches anddormers, and I-beams3. Panelised systemsPanels with timber orlight steel framing,structural insulatedpanels (SIPS) or crosslaminated timber (CLT)1. Volumetric constructionThree-dimensional units whichare fully fitted out off-site2. PodsPods are used inconjunction with anotherconstruction method.Examples are bathroomor kitchen podsNHBC Foundation Modern methods of construction 9This section examines the use of construction methodologies in residentialnew build as recorded by NHBC. It breaks down the use of MMC by typeand geography, and looks in detail at the use of panelised systems and offsite manufactured components. It indicates where decisions on constructionmethodology are being made and the willingness to innovate amongst thosebuilding new homes.5.1 NHBC statistics on construction typeNHBC records statistics on construction type on the new homes it registers,representing about 80% of new homes built in the UK. The figures show thatmasonry construction continues to account for the majority of new residential buildand the proportion has remained fairly constant over the last 8 years (Figure 2).Figure 2 New build, share by construction type in the UK (2008 to 2015)5 Use and consideration ofMMCOther Light steel frame Timber frame Masonry construction0204060801002008 2009 2010 2011 2012 2013 2014 2015Market share (%)Source: NHBC, based on registrations. YearUse and consideration of MMC10 NHBC Foundation Modern methods of constructionThe use of timber-framing or light steel-framing methods for the structure ofhomes represented about 16% of the new build market in 2015, having declinedfrom a high of 24% in 2008 (Figure 3).NHBC’s statistics do not, however, record the extent of use of sub-assembliesand components, which are used by more organisations involved in new buildthan structural forms of MMC.The UK figure masks differences in construction method between countries.In Scotland, timber frame is the conventional approach, where it accounted for75% of construction methods amongst NHBC-registered new build homes in2015. In Wales timber frame has experienced a higher share than in England,where market share is at its lowest.Figure 3 Timber frame market share in the UK, by country5.2 Use and consideration of different types of MMCThe majority of house builders and housing associations are using, or haveconsidered, at least one MMC approach within their recent build programmes.Of the large and medium-sized house builders and housing associationssurveyed, only two said they had not used or considered at least one form ofMMC in the last 3 years.The most used are sub-assemblies and components, installed by about threequarters of the house builders and just under half of the housing associations in2015. Panelised systems are the next most used MMC type (Figure 4).Very few have used full volumetric construction or pods in the 3-year period2013 to 2015 (Figure 5). However, these are being considered for future use byover a third of organisations: 37% are considering, or may consider, volumetricconstruction and 28% are considering, or may consider, using pods (sometimesknown as semi-volumetric). But opinion remains split with over half in each casehaving already rejected or unlikely to consider use at all.010203040506070802008 2009 2010 2011 2012 2013 2014 2015Scotland Wales EnglandMarket share (%)YearSource: NHBC, based on registrations.Use and consideration of MMCNHBC Foundation Modern methods of construction 11Figure 4 Percentage of all organisations using different types of MMC for new homes in 2015Figure 5 Percentage used and considered in the last 3 yearsEncouraged by historical Government funding conditions, housing associationsmight be expected to have the most experience of MMC; but it appears thatmore private sector house builders have been using pods, sub-assemblies andcomponents (Figures 6 and 7). The apparent lower use by housing associationsmay be due to their procurement of new homes through Section 106agreements or through design and build contracts, meaning that they may notalways select the method of construction used.By region, use of volumetric construction and pods has been almost entirely inLondon and the South East. Use of panelised system MMC is higher in Scotlandthan elsewhere due to the well-established tradition of building with timberframe. Use of off-site manufactured sub-assemblies and components is alsohighest in Scotland.Percentage used and considered020406080100Sub-assembliesand componentsVolumetric Pods Panelised Site-basedMMCNot considered andunlikely to do soHave consideredand rejectedPossibly will considerNot used butconsideringUsed in the last 3 years forat least one homeMMC type020406080Volumetric Pods Panelised Sub-assembliesand componentsSite-basedMMCPercentage of all organisationsMMC typeUse and consideration of MMC12 NHBC Foundation Modern methods of constructionFigure 6 Percentage of organisations using MMC at least once in 2015, by house builder andhousing associationFigure 7 Percentage of organisations using MMC at least once in 2015, by regionOther findings from the survey about the application of MMC show that:■■ MMC has been used for both apartments and houses, although pods havebeen mainly used for apartments; 97% of those using pods have installedthem in apartments in the last 3 years. By comparison, two-thirds of usersof panelised systems have used this approach for apartments and threequarters for houses.Percentage of organisations020406080Large house builders Medium-sized house builders Housing associationsVolumetric Pods Panelised Sub-assembliesand componentsSite-based MMCHouse builders/housing associationsBase: Large house builders (61), medium-sized house builders (39), housing associations (35).Volumetric Pods Panelised Sub-assembliesand componentsSite-based MMCPercentage of organisations020406080100 London and the South EastRest of England and WalesRegion ScotlandBase: London and the South East (49), Rest of England and Wales (73), Scotland (13).Use and consideration of MMCNHBC Foundation Modern methods of construction 13■■ The average number of storeys for which pods have been used is 14, and forvolumetric construction, 9.■■ MMC is not used as a blanket approach – a standard specification adoptedacross all sites; its use varies from site to site and suitability will often bejudged for each individual project. This explains why market share for theMMC systems is lower than the proportion of organisations with experienceof their use.■■ Almost all of those regarding themselves as MMC ‘market leaders’,representing 10% of those interviewed, have used panelised systems andsub-assemblies and components. Of the market leaders 3 in 10 have alsoused or have tried volumetric construction in the last 3 years and 2 in 10have used pods, ie above the market average.5.3 Types of panelised systems usedPanelised systems in use include ‘open panels’ (ie without plasterboard liningsfactory fixed) and ‘closed panels’ (ie plasterboard fixed in the factory) in bothtimber and light steel framing. In addition, this category includes structuralsystems such as SIPs and CLT. 42% of the organisations interviewed usedpanelised systems in 2015.The main type used is open panel timber frame, installed by just over two-thirdsof panel system users in the last 3 years (Figure 8). 39% of organisations haveused closed panel timber frame and 33% have used SIPs over the same period.This use of panelised systems is set to continue in 2016 with 49% expecting touse open panel timber frame, 32% closed panel timber frame and 22% openpanel light steel frame.32% said they are likely to use closed panel timber frame in 2016.Figure 8 Types of panelised system used in the last 3 years and anticipated use in 2016 (basedon percentage of organisations who have used panelised systems in the last 3 years)Percentage of organisations0 20 40 60 80 100Open panel timber frameClosed panel timber frameStructural insulated panels (SIPS)Open panel light steel frameCross-laminated timber (CLT)Closed panel light steel frameOtherNone of theseLast 3 years Anticipated in 2016Base: House builders and housing associations (77) as a percentage of those who have used panelised systems in the last 3 years.Use and consideration of MMC14 NHBC Foundation Modern methods of constructionThose who have used open panel systems cited several reasons for not movingto closed panels:■■ perceptions of capital cost and ‘up-front’ expenditure■■ being ‘not suitable’ for the specific project or site■■ reduced flexibility on-site, open panel is ‘tried and tested’■■ risk of damage in transport.5.4 Types of off-site manufactured sub-assemblies andcomponents usedThe survey revealed that the industry is currently making more use of subassemblies and components than it is off-site manufactured systems (volumetricconstruction, pods and panelised systems). Focus group comments showedthat components which have been manufactured or constructed off-site requireless on-site labour, are seen as efficient, improve build quality, have health andsafety advantages and do not attract some of the concerns associated withother types of MMC.The types of off-site manufactured components used by the highest proportionof companies are door sets, timber I-beams, prefabricated chimneys andprefabricated dormers (Figure 9).Housing associations’ stated use of these components is lower than that ofhouse builders. This could be because they are less aware of what is usedon-site when they acquire homes through Section 106 arrangements or throughdesign and build contracts.Figure 9 Types of off-site manufactured components used in the last 3 yearsPercentage of organisations0 20 40 60 80 100Door setsTimber I-beamsPrefabricated chimneysPrefabricated dormersFloor cassettesRoof cassettesPrefabricated plumbing systemsPrefabricated foundationsPorches/door canopiesOtherHouse builders Housing associationsBase: House builders (100) and housing associations (35).Use and consideration of MMCNHBC Foundation Modern methods of construction 15 5.5Where are decisions made about the constructionmethod? Decisions about the type of construction method on a new development, inmost house builders and housing associations, are made at the regional officelevel rather than at head office (Figure 10).Figure 10 Where decisions are made about the construction method5.6 Willingness to innovateThe majority of those interviewed regard themselves as ’followers’ or ‘lateadopters’ of volumetric construction, pods and panelised systems, rather than‘market leaders’ in using these forms of MMC (Figure 11).10% of the organisations surveyed described themselves as market leaders,mostly the large and medium-sized house builders rather than the housingassociations. Subsequent answers confirm, as expected, that the market leadersare using all the different forms of MMC to a greater extent than the majority ofthe market.16%60%24%16% – Centralised policy withregional adherence60% – Autonomous regional decisions24% – Centralised policy local flexibilityBase: House builders and housing associations (135).Use and consideration of MMC16 NHBC Foundation Modern methods of constructionFigure 11 Which best describes your company’s attitude towards the use of volumetricconstruction, pods and panelised systems?Large house buildersMedium-sized house buildersHousing associations15%46%29%10%15% – Market leader46% – Follower29% – Late adopter10% – Unlikely to use at all18% – Market leader43% – Follower26% – Late adopter13% – Unlikely to use at all 3%– Market leader68% – Follower20% – Late adopter9%– Unlikely to use at all 18%43%26%13%3%68%20%9%Base: 61.Base: 39.Base: 35.NHBC Foundation Modern methods of construction 17In this section the main reasons for considering the use of MMC amongst housebuilders and housing associations are described, together with the benefitswhich have been realised in practice. Experiences with volumetric constructionand pods used for apartments or houses are examined in detail together withthe likelihood for use again in the future.6.1 Main reasons for considering MMCThe main reason for considering use of MMC is to achieve a faster buildprogramme (Figure 12). The majority of house builders and housing associationsidentified this as their main driver and overall two-thirds gave this as one of theirtop three factors.Other reasons for considering MMC include improving build quality, tacklingthe skills shortage, and improving health and safety. Achieving a fastweathertight envelope, reducing costs and improving site efficiencies were alsomentioned. Housing associations are motivated by the need to deliver homesquickly, and cost effectively, and the results suggest they believe MMC will helpthem achieve this objective.There is an undisputed need for more new homes and the house-buildingindustry is steadily increasing its output. However, only 8% of house buildersdescribed a need to increase the number of units they build as a top threedriver for considering MMC, although 35% included it in a list of drivers whichhave influenced them to some extent (not shown).6 Factors drivingconsideration of MMC andexperiences in practiceFactors driving consideration of MMC and experiences in practice18 NHBC Foundation Modern methods of constructionFigure 12 Main reasons for using or considering MMC. Percentage stating as a top threedriver6.2 Benefits of MMC in practiceSection 6.1 showed that achieving a faster build programme was the mainmotivation to use MMC; this section explores what was encountered in reality.For the house builders using MMC, speed of construction had proved to be themain benefit experienced in practice. Housing associations were less convincedof this benefit; this may be explained by their lack of direct control over thebuilding programme, being reliant on their contractors/house builders.Whereas the ability to achieve a fast weathertight envelope did not rankhighly in the drivers to using MMC, it was commonly reported as a mainbenefit realised in practice. Other benefits include improved build quality,site efficiency and health and safety, and a reduction in labour and site waste(Figure 13).33% of house builders (36% of the large and 20% of the medium-sizedcompanies) have found that MMC has helped towards increasing the numberof units they build. However, none of the housing associations has found this;achieving a faster watertight envelope has been the main benefit reported byrespondents in this group.0 20 40 60 80Faster build programmeImproved build qualityTackle skills shortageReduce costs, improve profitabilityImproved health and safetyFast weathertight envelopeImproved site efficiencyMeet sustainability targetsMaterial shortagesReduce site wasteMeet planning requirementsIncrease number of units builtHouse builders Housing associationsBase: House builders and housing associations (133, weighted) prompted response from those using,have used or have considered MMC.PercentageFactors driving consideration of MMC and experiences in practiceNHBC Foundation Modern methods of construction 19Figure 13 Main benefits of MMC experienced in practice, percentage stating it as a benefitFewer than half (44% of house builders and 27% of housing associations)reported that they had experienced reduced costs/improved profitabilitydespite the potential for MMC to offer reduced preliminary costs, improvedcash flow and lead to faster sales revenues. The focus groups emphasised thatthese benefits will only be available in a strong sales market; some contributorshad not found that the preliminary costs could be reduced in practice.MMC is not considered to have made a useful contribution towards reducingreliance on specific building materials that have been in short supply as housebuilding output rose following the recession. Materials such as facing bricks arelikely to still be required regardless of whether or not the underlying structure isof MMC.House builders Housing associations0 20 40 60 80Faster build programmeFast watertight envelopeImproved build qualityReduced costs, improved profitabilityImproved site efficiencyImproved health and safetyReduced site wastageTackle skills shortageMeet sustainability targetsIncrease number of units builtAddress materials shortagesBase: House builders and housing associations using MMC in the last 3 years (120), prompted.PercentageFactors driving consideration of MMC and experiences in practice20 NHBC Foundation Modern methods of construction6.3 Experiences of volumetric construction and pods6.3.1 Volumetric construction34% of those interviewed have used, considered or are considering usingfull volumetric construction for apartments and/or houses. Most of theseorganisations are in London and the South East, a small number elsewhere inEngland and Wales and none in Scotland.12 organisations have used volumetric construction at least once in the last3 years and their mixed experiences are summarised in Figure 14.One-third of the organisations had a positive experience, but the remainderwere less positive as they have not encountered the expected benefits. Theirexperience has also highlighted the importance of paying detailed attention toco-ordination and planning well in advance of construction starting on-site andduring construction as well. Feedback from the survey highlights the followingissues:■■ There is the need to take design decisions and ‘freeze’ the design at anearlier stage; this reduces flexibility on-site, particularly for any last-minutechanges.■■ More comprehensive procurement planning of the whole development isrequired at the outset.■■ Despite the planning, more work has been found to be required on-sitewhen the off-site units are delivered, than was anticipated within theprogramme.■■ Cost benefits are not fulfilled in practice; logistics, weather delays and soon, quickly erode savings.■■ Low capacity exists within the supply chain, which constrains procurementchoice with some having encountered disappointment with deliveryperformance and product quality.In spite of these issues, the majority of respondents said that they would belikely to consider using volumetric construction again.Amongst the 17 organisations who had considered volumetric construction, butnot yet used it, 7 thought they might use it in future. Specific drivers for futureuse included where there is a need for speed, to overcome labour or materialshortages, and to help drive up quality or build volumes.Factors driving consideration of MMC and experiences in practiceNHBC Foundation Modern methods of construction 21Figure 14 Full volumetric users’ experiencesHave used volumetric construction fornew homes in the last 3 years (12)Positive experiences (4)“So far it is going well. The quality is good andproject is on target.” (Houses)“We feel there are enormous benefits, thesethings are developed in controlledenvironments and brought to site, so improvesquality, and therefore health and safety. Alsothe cost of going back to repair poorworkmanship is cut out.” (Houses)“Very, very good as long as we co-ordinated itupfront, otherwise it could be chaotic.”(Apartments and houses)“As expected. No surprises. Did lots of factoryinspection in order to ensure the qualityrequired.” (Apartments)Negative experiences (8)“The technology was quite new, it was a massive learning experience for themanufacturer and ourselves. The difficulty was the co-ordination on andoff-site.” (Houses)“You do more up front thinking. You have to programme more in advance,take decisions earlier on to finalise design.” (Apartments and houses)“Unfortunately while the principle was right, the reality of the finished articlewas less than expected. There has been a lot of opening up of flats to putthings right, you would expect this to be thought through better in thefactory. I don’t think the quality was better than we could have achieved bybuilding on-site. (Apartments)“We have used it on houses and it is not something I would rush and use. Itoften leaves you unprepared at site level and that is across the board. When itlands, the site is not geared up to put it up that quickly and you end up withservices not connected. They are so used to conventional delivery.” (Houses)Used for apartments (6) Used for houses (7)Likelihood of using again (4) Likelihood of using again (8)Yes (3)*“I would be amazed if we are not using it inthe next few years, the proposition is toocompelling.”“On confined sites with limited space it’sideal.”“Going to France next week to look at afactory which makes them.”*The 4th was unsure about future useYes (6)“Speed of construction. Suitable for typeof building undertaken by our company.”(Apartments)“We do consider it but it’s very sitespecific. Reduces site waste.”(Apartments and houses)“We need to look at it, eg if there arematerial shortages.” (Houses)“We would consider it in the rightcircumstances on the right site. We wouldconsider anything going forward that getshouses and apartments up quicker.“No (2)“It’s just a step too far, we aretrying to go more lightweightmetal frame, rather than thevolumetric. The kind ofapartments we are trying tosell don’t lend themselves tofull volumetric.”“With normal volume housebuilding it’s unlikely. There willbe limited bespoke uses likeemergency accommodationfor local authorities for waitinglists in the South East.”Factors driving consideration of MMC and experiences in practice22 NHBC Foundation Modern methods of construction6.3.2 Pods45% of organisations have used, considered or are considering pods in theirnew residential build.Of the 28 organisations which have used pods at least once in the last 3 yearsmost have had largely positive experiences (Figure 15). Amongst the mainreasons for using them and the benefits experienced, they highlighted theimproved build quality and reduced levels of snagging, reductions in site labourand a faster build, with improved programming and greater overall constructionefficiency.Almost all of those who have used pods would do so again, and most of thoseconsidering them expect to use this approach in future.The main problem experienced by both those who have used and those whohave rejected pods was the higher capital cost. Other drawbacks related tocapacity within the supply chain, with a lack of choice of suppliers who are ableto meet the needs of house builders. There have also been experiences ofproblems with suppliers being unable to meet the delivery programme as wellas companies going out of business. The logistics of transporting pods to sitehave also proved challenging due to the size of each pod.Other participants raised concerns about adverse customer reaction,particularly at the luxury end of the market. Concerns were also expressedabout where responsibility lies if there are problems during installation.Figure 15 Pod users’ experiencesHave used pods for new homes in the last 3 years (28)Positive experiences (89%)“We tend to use bathroom pods because of the quality. We believemost of the works happen in the bathroom, so we try to avoidrepetition of trades going in. It’s more about quality than anythingelse. The downside is that, because most of the volumetric contractorsare abroad, if it leaks it takes longer to get replaced.” (Apartments)“The flats went well, it reduced snagging.” (Apartments)“Quality was good. Programme benefits were achieved. Fewer defectswith bathroom pods as there is more quality control when it is factoryassembled.” (Apartments and houses)“Very good. Quality and finish excellent. Good on the programme.”(Apartments)“The experience has been good, there have been no issues withdelivery or installation and it’s been quicker than traditional build.”(Apartments)Negative experiences (11%)“Our conclusion was the use of pod constructionwas to put together cheap components.”(Apartments)“We used bathroom pods, it was a large scheme.We had supply chain problems. Given that it was abig project running to a tight timescale, we had totake un-kitted out pods and crane them in, thensupply and fit in situ. So we had the worst of bothworlds” (Apartments)“I think there is a nervousness around podmanufacturers, often they seem under-capitalisedand it can cause problems with cash flow. Overrecent years there has been a volatility withbusinesses coming into the market and thendisappearing.” (Apartments)Used for apartments (27) Used for houses (4)Likelihood of using again (25) Likelihood of using again (3)Yes (23)“The benefits are that it avoids the skillsshortages. They have to be stacked properlybut there are definite benefits.”“They are sealed units, they go in quickly andcan be used in a range of dwelling sizes.”“Benefits are that pods address the skillsshortages, also speed of build and quality, andhave more control as it‘s factory made.”Yes (1)“Because wehave clientsasking forthem. Thequality of buildoff-site in acontrolledenvironment.”No (2)“Probably cost”No (2)“Very few of the promised benefitsmaterialised. No improvements inquality, quality was worse than siteconstruction.”“I would rather go straight tovolumetric if we were going totake that step, rather than podswhere we have had some difficultywith the supply chain.”NHBC Foundation Modern methods of construction 23Concerns about the use of ‘whole home’ volumetric construction were firstexpressed in the focus groups and the results on drivers and use in Section 6corroborate that initial feedback. To assess the concerns in more detail andunderstand the extent to which these were barriers to future use, questionswere asked of the wider audience in stage 2 of the research programme.The initial observations in the focus groups were confirmed with the mainconcerns and barriers to use being the higher capital cost and the lack ofsuppliers. When asked how they perceive the costs associated with the use ofvolumetric construction in comparison with other approaches, two-thirds saidthey expect it to cost more.Other concerns raised in the wider telephone survey, not considered majorbarriers but nevertheless needing to be addressed, include reactions frompotential buyers, the availability of the right labour skills for installation, theneed for an early design freeze, a lack of flexibility on-site, transport logisticsand reactions from potential buyers.Respondents were asked to name two main barriers to using full volumetric ormodular construction (Table 2) from the list shown in Figure 16.7 Concerns and barriersto using volumetricconstructionConcerns and barriers to using volumetric construction24 NHBC Foundation Modern methods of constructionFigure 16 Concerns and barriers to use of full volumetric or modular construction (prompted)Table 2 Top barriers by type of organisation Large house buildersCapital costBuyer reactionsLack of suppliersMedium-sized housebuildersCapital costLack of suppliersLack of flexibility on-siteNeed for early design freezeHousing associationsCapital costLack of sub-contractor skillsLack of suppliers 0 20 40 60Increased capital costNeed for early design freezeLack of suppliersLack of flexibility on-siteTransport logistics, accessibilityand craneageRisk of problemsBuyer reactionsSub-contractor skills to erectLack of suitable modular options to meetplanners’ or customers’ expectationsRestricts bespoke options for customersNeed for cost/benefit modelsPossible down-valuation of homesLocal authority or planningreaction to modular designConcerns Main barriers to useThe dream of off-site …butwhen you get into reality,when you cost it up, withthe knowledge we have,there is the cost implication,and the hassle factor.(House builder)One of the biggest reasonswhy modern methods ofconstruction hasn’t taken off,particularly timber frame, isthat it’s a series of cottageindustries, it doesn’t sell itselfvery well. (House builder)The bulk of our work is inLondon and it’s flats onbrownfield sites, squeezingthem in here, there andeverywhere and that saysyou can’t standardiseanything. (House builder)Base:135. PercentageNHBC Foundation Modern methods of construction 25With a somewhat mixed picture emerging of both use and experiences to date,the research sought to gain insight into industry views about the future for MMC.Respondents were asked for their views on the potential contribution of MMCin the construction of new homes in the UK and the expected role it will playwithin their own organisations. They were also questioned about MMC, in thecontext of increasing housing output generally, over the next 3 years.By far the main contribution is considered to be the ability to build homesfaster, again corroborating the main benefit experienced in practice. But MMCis also expected to help house builders improve build quality and will beadopted by some to help address skills shortages (Figure 17).Figure 17 Views on MMC’s main future contribution to new build0 10 20 30 40 50 60Speed of construction/faster build programmeImproved/assured quality of buildEase the skills shortageIncreased volume/increased number of houses builtEnergy efficiency/sustainabilityBase: 135. Main unprompted answers given by over 10%. Percentage8 The future for MMCThe future for MMC26 NHBC Foundation Modern methods of constructionThe majority of house builders and housing associations interviewed feel thatMMC has some role to play in the delivery of large volumes of new homes(Figure 18), but identified other factors which need to be addressed. These areexamined in more detail in Section 9.0 10 20 30 40 50 60 70Some contribution but there are also other factorsA key roleNo contribution, it is used for other reasonsBase: 135. Responses were prompted. PercentageFigure 18 Expected role of MMC in significantly increasing UK housing inputIn spite of these factors, 78% of house builders and 46% of housing associationsexpect to increase the number of new homes they build over the next 3 yearsand MMC is expected to make some contribution in achieving this by themajority (Figure 19).Figure 19 Some comments about the contribution of MMC to the new build sectorLook at what the Chinese are doing,they can build 32 modular storeys in24 weeks and the build quality looksvery good. We could use it all overLondon. It could revolutionise thebuilding industry. We have so manysub-contractors on our books it wouldmake them null and void.(House builder)It’s definitely a more efficient way of building.It probably has less impact on thesurrounding environment we are working in,for example you are not delivering so manymaterials on-site. The end user benefits fromthe efficiency of the house. Less time is spenton-site so the surrounding environment isless impacted. (House builder)The contribution of MMC is the abilityto deliver a limited range of similardwellings quite quickly. It’s almost akinto the prefabs of post war. The realoffering is the speed of constructionand being able to develop the productin a factory environment. The next stepis to take away any wet trades,particularly external wet trades affectedby weather conditions. (House builder)With houses its contribution is limited. Thelarge house builders have not bought into it.Go down the open panel timber frame route,fine, but putting fully volumetric in doesn’tstack up, it’s all about volume. If you have got athousand homes to deliver which are the samethat’s fine, you could probably go intopartnership with an MMC builder. But if youhave a stop/start programme when you can’tguarantee the supply of MMC that increasescosts. So timber frame is fine, anything more‘modern’ than that makes it a lot more difficultfor the industry to deal with the lack offlexibility. (Housing association)We only need to build a certain number eachyear, we are not a volume builder. But it allowsus to phase a site better, allows us to getstreetscapes in better, it allows our sales teamto actually sell, not a building site as such, butan area to live, so we can actually movepeople in to a finished street a lot quicker.(Housing association)The future for MMCNHBC Foundation Modern methods of construction 27It is expected that the use of MMC is likely to grow over the next 3 years; 45%anticipate that it will play a greater role in their organisation’s constructionprocesses. Only 3% of those surveyed expect the role of MMC to decline(Figure 20).Figure 20 Anticipated role of MMC in organisations’ construction processes over the next3 yearsConcerns over skills shortages, which are expected to continue over the next3 years, were given as the main reason encouraging the use of MMC. Otherreasons are a wish to increase build speed and housing output and to improvequality (Figure 21).Figure 21 Main reasons why MMC is expected to play a greater roleBase: 135.0 10 20 30 40 50 60 70 80 90 100AllLarge house buildersMedium-sized house buildersHousing associationsGreater role Same role/no change Smaller role Don’t knowPercentage0 5 10 15 20 25 30 35 40 45 50To overcome skills shortagesFor a faster build programmeTo increase housing outputTo improve build qualityGovernment policyTo address materials shortagesTo reduce costsBase: 61 organisations expecting MMC to play a greater role.PercentageThe future for MMC28 NHBC Foundation Modern methods of constructionPanelised systems and sub-assemblies and components are expected tocontinue to be the most used type of MMC over the next 3 years (Figure 22).The use of ‘whole home’ volumetric construction and pods is expectedto increase over the next 3 years. 19% think they will be using volumetricconstruction and 28% pods in that timeframe, significant increases compared to6 to 7% who said they used each approach in 2015.Figure 22 Types of MMC used in 2015 and expected to be used in 3 years’ timeThere are differences by type of organisation (Figure 23); twice as many housingassociations than house builders think they will be using volumetric constructionin 3 years’ time. Also, the proportions of large house builders and housingassociations using panelised systems to some extent is anticipated to increasesignificantly.Significant differences are expected to continue by region (Figure 24), withanticipated use of volumetric construction and pods increasing predominantlyin London/the South East and high levels of panelised system constructioncontinuing in Scotland, but also increasing in the rest of the UK.Percentage01020304050607080Volumetric Pods Panelised Sub-assembliesand componentsSite-based MMCUsed in 2015 Expect to be using in 3 years’ timeBase:135.The future for MMCNHBC Foundation Modern methods of construction 29Figure 23 Types of MMC organisations expect to be using in 3 years’ time, by type oforganisationVolumetric Pods Panelised Sub-assembliesand componentsSite-based MMCVolumetric Pods Panelised Sub-assembliesand componentsSite-based MMCVolumetric Pods Panelised Sub-assembliesand componentsSite-based MMC01020304050607080Used at least once in 2015 Expect to be using in 3 years’ timeUsed at least once in 2015 Expect to be using in 3 years’ timeUsed at least once in 2015 Expect to be using in 3 years’ time*0102030405060708001020304050607080Large house buildersMedium-sized house buildersHousing associations*7% said they do not expect to be using any of these in 3 years’ time.Percentage Percentage PercentageThe future for MMC30 NHBC Foundation Modern methods of constructionFigure 24 Types of MMC organisations expect to be using in 3 years’ time, by region0102030405060708090010203040506070800102030405060708090Volumetric Pods Panelised Sub-assembliesand componentsSite-based MMCUsed at least once in 2015 Expect to be using in 3 years’ timeVolumetric Pods Panelised Sub-assembliesand componentsSite-based MMCUsed at least once in 2015 Expect to be using in 3 years’ timeVolumetric Pods Panelised Sub-assembliesand componentsSite-based MMCUsed at least once in 2015 Expect to be using in 3 years’ timeScotlandLondon and the South EastRest of England and WalesPercentage Percentage PercentageThe future for MMCNHBC Foundation Modern methods of construction 31When asked for views on where the industry is most likely to see growth inMMC over the next 3 years, the most common answer was panelised systems(Figure 25).Figure 25 MMC approaches considered most likely to grow in use in new build over the next3 yearsAmongst those who feel that their use of volumetric construction and/or podswill grow, their reasons are similar to those given for encouraging greater use ofMMC generally, ie faster build time, addressing skills shortages and helping tomeet demand (Figure 26).Those not anticipating increased use consider that these methods remainunfamiliar and therefore carry some risk which they are not willing to take.0 10 20 30 40 50 60PanelisedPods orsemi-volumetricSub-assembliesand componentsVolumetricOn-sitemanufacturedDon’t knowNone of theseBase: 135.PercentageThe future for MMC32 NHBC Foundation Modern methods of constructionFigure 26 Reasons for and against use of volumetric construction and/or pods in future(unprompted)To me the biggest driver is to doubleproduction, you can’t do that withtraditional construction. I think that’swhere the Government is going, withthe housing shortage. We don’t havethe people or the materials to dothat. (House builder)We feel there are enormous benefits,these things are developed incontrolled environments and brought tosite, so it improves quality, and healthand safety. Also the cost of going backto repair poor workmanship is cut out.(House builder)I think we are quite risk averse andmodern methods of constructioncarries risk with it. Wherever we havetried things we have ended up withproblems we weren’t expecting interms of aftercare, some quite seriousand significant. (Housing association)As we have come out of the recessionthere has been a need to look elsewhere.It is having the confidence to go intosome of these other items. We are quiteused to timber frame. But to have theconfidence to go into something which isuntried, untested, don’t know how it worksand these people tell us they can do it.But if they fail…? (House builder)For speed/faster build time (32%)Help address skills shortage (30%)Help meet demand (23%)Risk of unfamiliar systems and public perception (41%)Expensive (26%)Insufficient capacity in supply chain (12%)Market prefers traditional buildings and methods (12%)NHBC Foundation Modern methods of construction 33It is clear from the research that the use of components and sub-assembliesis very well established. The use of panelised systems, already standard inScotland, is developing and is clearly expected to continue. However, toprogress the move towards greater use of pods and whole home volumetricconstruction, the perceived barriers need to be overcome, and the benefitsdelivered such that they outweigh the drawbacks, reinforcing the case forgreater use.This issue was debated amongst the focus group participants who identifiedthe following list of key issues preventing or restricting greater use of fullvolumetric construction. The main issues are shown in blue shading in Table 3.Table 3 Key issues identified for preventing or restricting greater use of full volumetricconstruction Risk, including lackof suppliersThe risk factor was raised unprompted at both stages of the research; use ofan unknown or unfamiliar approach, and the effect on costs, site issues, labourrequirements and importantly customer attitudes. Also the risk of using what areoften small suppliers who were described as not understanding the house-buildingindustry.Analogies were draw with countries like Japan where there are several large andexperienced companies successfully supplying high volumes of modular homes – amore developed supply chain, delivering more confidence.Increased costDescribed as a main barrier to use, some companies find that savings on-site,for example, resulting from shorter construction duration and health and safetybenefits are not taken into account in financial models. Others had been unable toachieve significant site savings to counter the higher capital cost, in preliminaries forexample. 9 Factors to be addressed forincreased use of MMCFactors to be addressed for increased use of MMC34 NHBC Foundation Modern methods of construction Buyer reactionsand restriction onbespoke customeroptionsThere is concern about buyer reactions to volumetric construction – it may be seenas a ‘cheap’ approach with association with ‘prefabs’, although some house buildersare describing off-site as providing better quality of construction.The opportunity to offer bespoke options to customers is more limited anddecisions need to be made earlier on – restricting buyer options if an off-plan buyerwithdraws from purchase or the home is sold post construction.Requirement forstandardisationThe view was expressed that house types need to be varied to suit localrequirements for planning and marketing purposes, but an expectation thatvolumetric construction is suited to standardised or repetitive designs. Thereis thought to be a lack of suitable modular options which meet planners’ andcustomers’ expectations.Need for earlydesign freezeDesigns may need to be changed slightly for a number of reasons; the industry isaccustomed to working with some flexibility in design – that volumetric designsmust be fixed at an earlier stage is considered by some to be an unwelcome andimpractical way of working.Transport logisticsTransporting large units to sites which may be restricted in size and difficult toaccess, and requiring hoisting, is seen as adding cost and limiting use.Lack of subcontractor skillsA lack of skills to install volumetric units and a lack of understanding about workingwith them. Suggestions made during the course of the research to encourage use ofvolumetric construction include:■■ dissemination by MMC manufacturers of cost/benefit models and bestpractice case studies■■ encouraging suppliers to enter the market (some have in fact left it in thelast 3 years) and improving their understanding of the house-building sector■■ finding ways of working with suppliers to overcome industry concerns■■ grant or subsidy-funded development■■ improving awareness and understanding of what volumetric construction isamongst potential homebuyers.To be adopted by the industry on a widespread basis, volumetric constructionneeds to be seen to be providing benefits for house builders. At present otherMMC approaches, such as panelised systems and sub-assemblies, are seen tobe enhancing the build process by increasing the speed of construction andimproving quality; given the concerns about full volumetric construction, thesealternatives are providing solutions sufficient for many house builders’ andhousing associations’ needs at present.NHBC Foundation Modern methods of construction 35Appendix AAppendix A:Focus group attendees OrganisationNameJob titleAster GroupTony CliffordDevelopment DirectorAvant HomesStuart RowlandsDevelopment DirectorBarrattOliver NovakovicTechnical and Innovation DirectorBarratt East ScotlandAndrew RuleDesign ManagerBarratt East ScotlandMartin EagleshamSenior Architectural TechnicianBellwayJohn KerrManaging DirectorCalaMarc CoulonGroup Construction and Technical DirectorCCG HomesDaniel McGannPartnership and Innovation ManagerChurchillHacon EdgleySustainability ConsultantClyde Valley HousingAssociationGerard EardleyTechnical InspectorCruden EstatesDavid McEvoyConstruction DirectorGuinness TrustMichael WattsHead of Partnerships Design and QualityHanoverMartin WhaleQuality and Programme ManagerHousing 21Steve HogbenNational Construction ManagerKeepmoatPeter HindleyManaging Director: HomesKierJim CollinsGeneral ManagerLink GroupGeorge AndrewClerk of WorksMactaggart and MickelRoss MickelDirectorNetworkDavid FosterHead of ConstructionNotting Hill HousingAssociationEd BadkeDevelopment DirectorOctavia Housing AssociationDave WoodsDevelopment DirectorRiverside GroupGeoff FogdenDirectorSpringfield PropertiesJames JohnstoneTimber Frame Design ManagerSpringfield PropertiesRaymond StevensonTimber Frame Design ManagerSwan HousingDeane RosewellCommercial DirectorTaylor WimpeyJohn GainhamDivisional Managing DirectorThenue Housing AssociationBeth ReillyHead of Property ServicesWaterloo HousingNeil AdieGroup Head of Development 36 NHBC Foundation Modern methods of constructionAppendix BAppendix B:Weighting of resultsWhere ‘all’ results are given in this report, weighting factors have been appliedto ensure each segment interviewed, ie large and medium-sized house buildersand housing associations, has a ‘share of voice’ of the ‘all’ figures which is inproportion to the number of new homes each group developed in the totalmarket in 2015.To arrive at this, the number of homes developed in 2015 by each officeinterviewed was recorded (within bands). This was then compared with theproportion of homes each group built in the total market by the groupsincluded in the survey (ie excluding those building under 200 homes).For example, of the total number of homes built in 2015 in the sample, 26% werebuilt by medium-sized house builders. However, medium-sized house buildersaccounted for 15% of all new homes built in 2015 by the groups included inthis research. Hence a weighting factor of 0.15 has been applied to results fromthis group to arrive at the aggregated or ‘all’ results, to ensure their views arerepresentative in proportion to the number of homes this group actually built.This ensures that, if any group holds a very different view to other groups, theiranswers are not over- or under-represented in the total.Weighting factors are given in Table B1.Table B1: Application of weighting factors to ensure aggregated or ‘all’ answers arerepresentative Homesbuilt as apercentageof total insampleHomesbuilt as apercentageof actualsin 2015*Weightingfactor†Large house buildersOver 1,000 homes per annumnationally55%60%0.60Medium-sized house builders200 to 1,000 units per annumnationally26%15%0.15Housing associations19%25%0.25* Note that the sample in the research did not include those building fewer than 200homes a year.† Each group’s answers to individual questions has been weighted by these factors toensure their ‘voice’ is in proportion to their share of new homes built. NHBC Foundation Modern methods of construction 37References and further readingReferences1 Department of Trade and Industry. Rethinking construction (The Egan Report).London, Department of Trade and Industry, 1998.2 Department of the Environment. Constructing the team. Joint review ofprocurement and contractual arrangements in the United Kingdom constructionindustry (The Latham Report). London, Department of the Environment, 1994.3 NHBC Foundation. A guide to modern methods of construction. NF 1. MiltonKeynes, NHBC Foundation, 2006.Further readingUK House builders directory 2015.www.propertydata.com.Construction Products Association. Construction industry forecasts 2015–2019.London, Construction Products Association, 2015.www.constructionproducts.org.uk.The NHBC Foundation, established in 2006, provides high quality research andpractical guidance to support the house-building industry as it addresses thechallenges of delivering 21st century new homes. Visit www.nhbcfoundation.orgto find out more about the NHBC Foundation research programme.© NHBC Foundation. June 2016Published by IHS BRE Press on behalf of the NHBC FoundationISBN 978-1-84806-451-5NF70Modern methods of constructionViews from the industryThe UK has a long history of using modern methods of construction (MMC),with many systems being introduced since the Second World War, to increasehousing output in the UK.Based on an extensive survey of house builders and housing associations, thisreport explores current industry attitudes towards MMC. It records the degreeto which different methods and systems have been adopted and assesses theappetite for more extensive application of specific approaches.The research finds an industry, which, while cautious in its approach, isnevertheless embracing MMC in its many forms, and remains ready to explorenew options and innovations.
