Among measures demanded, the MPs want a mandatory requirement for whole-life carbon assessments for buildings, greater priority to be given to retrofit over demolition/reconstruction and the production of a national retrofit strategy.
With the built environment responsible for 25% of the UK’s greenhouse gas emissions, the House of Commons environmental audit committee (EAC) slams the government for a lack of action in assessing and reducing these emissions.
Whole-life carbon assessments for buildings should be fully incorporated in building regulations and the planning system, the EAC’s latest report says. Such an assessment would calculate the emissions from the construction, maintenance and demolition of a building, and from the energy used in its day-to-day operation. The committee says that the UK is lagging behind the Netherlands and France, which have established mandatory whole-life carbon assessments for their built environment.
Once these assessments are in place, the government should develop carbon targets for buildings to align with the UK’s net zero goals. A timeframe for introducing whole-life carbon (WLC) assessments, and ratcheting targets, should be set by the government by the end of 2022 at the latest, and they should be introduced not later than December 2023, the report says.
The report, called Building to net zero: costing carbon in construction*, states: “Local authorities are mandating WLC assessments of their own accord. Evidence so far shows that the policy is achievable and is working, with few barriers to its introduction. Introducing mandatory WLC assessments for buildings could be an easy way for the government to dramatically reduce carbon in construction. The industry has repeatedly asked for an ambitious, clear timeframe for when whole-life carbon assessments will become mandatory. This timeline should align with the introduction of the Future Homes Standard, which should itself be brought forward to 2023. This will help bring together efforts to tackle operational and embodied carbon within the same timeframe.”
It also says that retrofit and reuse of buildings, keeping the carbon locked in, should be prioritised over new build. While the government states it is already prioritising retrofit and reuse, the committee said it was concerned that reforms to permitted development rights “appear to have created an incentive for demolition and new-build over retrofit”. It adds: “The government must therefore urgently evaluate the impact of recent reforms to ensure that retrofit and reuse are prioritised.”
Where retrofit is not possible, the EAC recommends more effective use of low-carbon building materials. The government’s investment in the development of low-carbon cements is welcomed, and mandating whole-life carbon assessments for buildings could encourage the use of more recycled steel and other recycled building materials. EAC recognises the potential of timber as a low-carbon construction material, though the committee identified hurdles to its wider use, such as appropriate sourcing, enhanced tree planting and a current skills gap in timber use in construction.
As EAC has identified in previous reports, the UK is facing a skills gap in energy efficiency and retrofit. It therefore reiterates a previous recommendation that a retrofit strategy and upskilling programme be developed and published. In addition, EAC recommends that training in undertaking whole-life carbon assessments is made accessible through the education system.
Philip Dunne MP, chair of the environmental audit committee, said: “From homes to offices, retail units to hospitality venues, our buildings have a significant amount of locked-in carbon, which is wasted each time they get knocked down to be rebuilt, a process which produces yet more emissions.
“Ministers must address this urgently. Promising steps are being taken: for instance, the levelling-up, housing and communities secretary of state [Michael Gove] recently paused the demolition and retrofit of Marks & Spencer on Oxford Street on environmental grounds.
“But much more needs to be done, and baseline standards for action need to be established. Mandatory whole-life carbon assessments, and targets to crack down on embodied carbon, provide part of the answer. Constructors and developers can then determine which low-carbon materials, such as timber and recycled steel, they can use.
“As in many other areas in the drive to net zero, the UK must have the green skills to make its low carbon future a reality. Before the summer recess in July, I urge the government to publish a retrofit strategy and upskilling programme that can ensure the UK economy will have the green jobs necessary to deliver a low-carbon built environment.”
Claire Ackerman, executive director (concrete) at the Mineral Products Association, said: “We welcome the balanced approach the committee has taken, and strongly back the recommendations to support whole life carbon assessments and to drive demand for low carbon cements and concretes, through public procurement and more widely across the construction sector.
“The concrete and cement industry has already reduced carbon emissions by more than 50% since 1990, decarbonising faster than the UK economy as a whole, and we have a robust and credible roadmap to go beyond net zero by 2050. We are seeing really positive progress on the delivery of that roadmap by the UK concrete and cement industry, supported in many areas by government funding under the industrial decarbonisation strategy.
“It is welcome that the report seeks to deliver lower carbon construction using all materials more efficiently. However, it is very important to recognise that it also falls into the trap of focusing on low carbon materials rather than low carbon solutions. The difference matters because, over the whole life of a structure, lower embodied emissions in the materials used to build it may lead to higher overall emissions if they are less energy efficient.”
Confederation of Timber Industries chair Alex Goodfellow said: “Timber is already a £10bn supply chain in the UK, which supports 350,000 jobs. It provides economic prosperity in every region of the UK, green employment, thousands of healthy, safe, warm, and beautiful low-carbon homes, and is helping create a sustainable construction industry.
“Right now we have an opportunity. We need to build more homes. We also need to make our existing homes more efficient, and reduce demolition. Timber can allow us to meet both these needs and rapidly decarbonise our built environment.
“By using more wood we can achieve quicker, higher quality, and safer construction, as timber lends itself to modern methods of construction by being manufactured offsite with factory precision, and extend the use of existing building, with light-weight timber structures able to lend additional stories.
“In addition, each time we use timber, it supports growing more trees. Timber keeps forests standing by incentivising landowners to engage in sustainable forestry, as for every tree harvested and placed on the market, several more trees are planted.”
Timber Development UK chief executive David Hopkins added: “One of our biggest roadblocks to making the changes necessary to address climate change is a mindset which perceives the shift to a net-zero economy as down the road, in the future, and reliant upon unproven technologies to decarbonise the industries most responsible for emissions.
“We already have a solution. Wood is the only sustainable structural material which can enable substantial decarbonisation of the built environment based on existing business models and proven technology. It can provide vast carbon sinks in our rural areas and carbon stores in our cities.
“There is widespread industry agreement that using more timber in place of carbon-intensive materials, such as steel, masonry, and concrete, is the best route to reducing carbon emissions from the built environment. This report reflects that and calls on the government to do more.
“As an industry, we are already taking up the challenges laid down in this report. Recently we formed Timber Development UK, merging the Timber Trade Federation and TRADA to form an organisation that can support the timber supply chain from supplier to specifier.
“From this position we are now setting out to empower all with the knowledge and confidence to use the world’s lowest-carbon building material – wood. By doing so we will close the skills gap and ensure that UK architects, engineers, and designers have the tools to succeed in building net-zero.”
Building to net zero: costing carbon in construction is available at publications.parliament.uk