UK construction needs to take advantage of its exceptional expertise and move towards more climate-positive methods, Lukas Thiel says
I work in a London studio on UK projects, but my background is as an architect in Sweden. In my transition to working in the UK, I have found it striking that, despite the UK’s high levels of enthusiasm for MMC and Design for Manufacture and Assembly (DfMA) and the considerable industry buzz surrounding it, these ideas are often embraced in the early stages of a project but routinely dropped further down the line, as decision makers revert to traditional methods.
Observing this repeating pattern, my growing concern is that the UK risks missing the opportunity to move towards carbon neutral building in line with its European counterparts. In Scandinavia, for example, traditional on-site building with bricks & mortar is now viewed as an “old means of construction”.
The more I work with the UK construction industry, the clearer it becomes how fundmental the shift is to make MMC and DfMA a cost-effective and viable option for housebuilding. The UK needs to take advantage of its exceptional level of expertise in research and engineering and move towards a climate-positive means of construction.
The vast majority of homes in Sweden are built using MMC, and much research is dedicated to progressing MMC engineering
I attempt to break down some of the key contributing factors in the outlined six points below:
System thinking and production pipelines
Any use of MMC and DfMA needs to be rooted in system process thinking. It should be included in the initial viability assessment of a project, and built into key timeframes – from the planning process and start date on site, through to the desired release date of properties to the market or for rent.
Logistics and contracts
MMC logistics are also different, with an emphasis on precision delivery times, with confirmed access routes and crane lift capacities. Different skill sets are required, impacting on local training and job opportunities. Longer lead-in times for MMC also put pressure on contracts, another reason why the shift in system thinking needs to start as soon as the idea to develop a site is conceived.
A key difference between MMC or DfMA and traditional construction is that the main MMC subcontractor often provides the structural frame, if not whole ready-built volumetric modules, which comprises the largest single construction cost. The use of MMC also reduces the need for manual labour on site, reducing the contractor’s workforce. Combined, this requires a shift in the main contractor’s business model, to allow for reasonable profit margins.
Before a factory can start producing building elements, every design decision around a project needs to be resolved, right down to the nuts and bolts. As every manufacturer has its own technical platforms, relying on specific means of assembly and limits set by factories, the MMC subcontractor should be part of the design team from the word go.
This will enable them to help designers to predict basic limitations, and accommodate for manufacturer-driven decisions regarding the type of MMC (full-frame and envelope, frame only, volumetric, timber, hybrid or concrete for example), up to and including RIBA Stage 2.
UK-sourced timber for structural purposes is not as strong as Scandinavian timber, and is not as available (Scandinavia, to a large extent, is covered by forest). Concrete, on the other hand, is easier to source locally. In both cases the limited numbers of UK-based MMC manufacturers form a bottleneck, with limited competition on price.
An effect of Brexit is that manufacturers and contractors have been looking to secure local sourcing of materials to avoid uncertainty on possible tariffs and delays. Looking forward, promoting UK sourced timber could see shorter structural spans or the introduction of hybrid solutions with steel beams.
A health and safety benefit of using prefabricated or volumetric facade elements is the limited risks on building sites from accidents such as falls. Another benefit is the higher precision and improved air tightness that it offers, making it easier to meet UK building regulations.
CLT however, often used in conjunction with MMC, is impacted by the recent changes to UK regulations as a result of Dame Judith Hackitt’s report, following the tragic Grenfell Tower fire. As a result, mortgage lenders and insurance companies shy away from the use of timber in multi-residential buildings, creating financial risk for developers and homebuyers alike. Without proper testing and certified technical solutions, timber is subject to an emotional stigma.
Extensive fire testing has been carried out in the US, Canada and continental Europe where CLT has been cleared for use in residential buildings. These tests and the derived standards, however, have effectively been ruled out by the report, leaving the future of CLT for use in residential buildings in the UK uncertain.
The contributing factors listed above, which are by no means exhaustive, can at first glance make systematic change in the industry seem more remote than ever. However, breaking obstacles down is an important step, in both understanding and overcoming them.
Here, I think it is useful to look to another country entirely, such as Sweden; where the shift to MMC has been largely driven by the manufacturing industry, and commercial opportunities grasped by factories.
The starting point for Sweden’s shift was arguably in the 1960s when, under a utilitarian and pragmatic rationale, top-tier contractors invested in setting up their own technical platforms. These platforms were not standardised, but specific to each contractor, with building regulations forming the ultimate framework.
This systemic thinking was first applied in the timber industry but later also applied to prefabricated concrete. Today a vast majority of homes in Sweden are built using MMC, and much research at higher education level is dedicated to progressing MMC engineering.
Obviously environmental factors between Sweden and the UK vary hugely and industry drivers in the UK are subject to very different forces, but by staying mindful of the obstacles and being open to the opportunites around MMC, the UK can and must form its own story out of the past and into the future, with all sectors within the industry remaining alive to change.
As with Sweden and the UK, each country within Europe has a unique context, with varying factors including building regulations, industry traditions, labour costs and climate, meaning the approach to MMC always differs but the the common denominator is always the systemic process thinking and business models.
By learning from our European counterparts, we can make the move to rolling out a climate-positive means of construction more widely.
Lukas Thiel is a partner at White Arkitekter working in the firm’s London studi