In 2019 the UK became the first major economy in the world to pass laws to end its contribution to global warming by 2050. In June 2021, the G7 followed suit, with a commitment to set out a roadmap to net zero greenhouse emissions by 2050.
Victoria Brayshaw is head of development and residential at Tetra Tech
The last year has challenged the resolve of the UK construction industry and generally speaking the industry has delivered. Against a backdrop of a global pandemic, homes have been built, foundations have been poured and infrastructure has been delivered. We pulled together. We must now bring this resolve to the climate emergency. The construction industry is a key partner in the mission to reach net zero.
When considering the scale of the challenge, it’s easy to see why the sector is looking at Modern Methods of Construction (MMC) as a potential solution. MMC encompasses a range of approaches that spans off-site, near site and on-site pre-manufacturing. They involve a manufacturing led fabrication or consolidation process in controlled conditions prior to final assembly and have the potential to speed up delivery, reduce cost, improve quality and importantly, reduce waste and emissions.
Waste has long been a major challenge for the industry. Statistics by Defra indicate that in 2016 construction and demolition activities generated 66.2M.t of non-hazardous waste, with nearly 5M.t going to landfill. This is where MMC plays a vital role. A study by KLH Sustainability, comparing modular and traditional construction, demonstrated how waste can be more easily monitored and minimised through MMC, resulting in over 45% reduction in material use and over 50% reduction in waste.
Emissions are a further challenge. According to the UK Green Building Council, around 10% of the country’s carbon dioxide emissions are directly associated with construction activities. This rises to 45% when considering the whole of the built environment sector. Off-site manufacture minimises the time and energy spent on site, with a reduction in noise, disruption and pollution in the surrounding area.
Housing secretary Robert Jenrick has stated emphatically that MMC will form a central part in delivering the UK’s housing needs, providing ‘not just more homes, but more beautiful, more sustainable, better quality homes in all parts of the country.’
MMC clearly have the potential to be significantly more productive than traditional methods; allowing homes to be built more quickly, addressing labour and skills shortages and improving the quality, consistency and energy efficiency of new homes. There are certainly challenges to overcome, not least in public perception. Off-site construction for many is synonymous with post-war modular schemes, conceived as a way of building at scale rather than delivering quality.
Topography can also be a barrier. Some volumetric systems require a flat footprint and are less suited to topographically challenged sites. Also, the distance between manufacture and installation is clearly a material consideration and this may limit the use of MMC.
However, MMC is particularly well suited to the affordable and PRS markets and therefore complimentary to areas with a policy requirement for high levels of affordable housing and locations where there are no restrictions on the introduction of other tenures. The provision of large numbers of similar homes reduces up front fabrication cost and provides much needed certainty of demand.
It is for this reason that Homes England are pushing the agenda. As part of the Affordable Homes Programme, Homes England are seeking strategic partnerships for the delivery of up to 130,000 homes. One of the requirements is that 25% of projects must be delivered using MMC.
If we are to achieve the dual challenge of reaching carbon neutrality while meeting the Government’s ambition to build 300,000 new homes a year, sustainable construction will be crucial. In the end, we have an obligation to future generations to find better ways to build, to ensure that the homes we create meet the needs of today without compromising the needs of the future.
*Victoria Brayshaw is head of development and residential at Tetra Tech
Department of Civil Engineering Department of Civil Engineering – International Burch University (ibu.edu.ba)