COP26 promised of 68% reduction in carbon emissions by 2030. Given the significant contribution (25%) that the built environment makes to the emission of greenhouse gases, both the industry and government have a key part to play in reaching those targets and in achieving net-zero by 2050.
Much of the existing regulation has been on making buildings more efficient by focusing on operational emissions, but the Environmental Audit Committee (EAC) has recently suggested that the "single most significant policy" the government could introduce to reduce carbon emissions from the built environment is a mandatory requirement to undertake whole life carbon assessments for buildings. In their report, "Building to net zero: costing carbon in construction", the EAC go on to recommend that this key policy is introduced no later than December 2023 for certain buildings through new Building Regulations.
Following hot on the heels of the EAC report, the private members' Carbon Emissions (Buildings) Bill, sponsored by Jerome Mayhew, has been re-introduced to Parliament and is due to have its second reading on 25 November 2022.
Taking the initiative
The lack of policies to measure and regulate embodied carbon in buildings has led to the development of numerous voluntary industry initiatives to support the control of embodied emissions from buildings. For example, the UKGBG Net Zero Whole Life Carbon Roadmap for the Built Environment set out a pathway to net zero and the industry-led suggested amendment to the Building Regulations, Part Z dealing with whole-life carbon assessments is ready in draft form.
Methodologies to measure and assess embodied carbon are readily available, the most widely used being the RICS Professional Statement on Whole Life Carbon. Carbon impact assessments form part of the planning process for large schemes of some local authorities. We can also look forward to a cross-industry UK Net Zero Carbon Buildings Standard, which seeks to develop metrics by which zero-carbon performance of buildings is evaluated.
It is clear from these various initiatives that industry has the means to measure and reduce embodied carbon. What is lacking is policy and regulation and a clear standard assessment for buildings to comply with.
Carbon Emissions (Buildings) Bill
The Carbon Emissions (Buildings) Bill, if passed, would therefore be a significant development for the construction industry since it would be the first national regulation of embodied carbon in buildings in the UK.
Based on the work of the Part Z campaign, the Bill would mandate the reporting of whole-life carbon emissions from buildings, and set limits on embodied carbon emissions in the construction of buildings. Projects greater than 1000m² or 10 dwellings would need to address and report their whole life carbon from specific dates with limits on embodied carbon emissions being introduced from 2027 based on the data collected in the preceding years. Data collection and measurement are key to managing the progress of de-carbonisation but meaningful measurement and valid comparisons of outputs require a consistency of approach, for example in the assumptions made and sources of data used. Until a national standard is developed, the EAC recommend that the government establish the RICS methodology (once it has been updated) as the industry standard.
Other supporting EAC policy recommendations
In addition to the recommendation to introduce mandatory whole-life carbon assessments, the EAC report made a number of other supporting policy recommendations aimed at helping the transition to a low-carbon built environment. This recognises that while mandatory whole -life carbon assessments are in themselves likely to drive the development and use of low-carbon construction materials, such as low-carbon concrete, and encourage greater recycling and investment in retrofit and reuse of buildings, other initiatives can also incentivise this transition.
These include:
- Clear timelines and targets - government should set clear timescales for the progressive tightening of carbon targets by the end of the year.
- Planning system – the requirement for whole-life carbon assessments should be reflected in the planning system through national planning policy and local authorities should be encouraged and supported to include this requirement within their local plans.
- Re-evaluation of permitted development rights – the impact of permitted development rights should be reviewed in conjunction with the overhaul of the planning system to ensure alignment with government commitments to promote re-use and retrofit.
- Procurement Bill – completion of whole-life carbon assessments for major public projects should be mandated in the Procurement Bill currently making its way through Parliament, and these assessments should be a pre-condition to participation in public works tenders.
- Incentivise retrofit and re-use of existing buildings – VAT rates of new buildings should be harmonised with retrofit work to incentivise retrofit and re-use ahead of new build/demolition to conserve materials, minimise embodied carbon emissions and reduce demolition waste.
- Environmental Product Declarations – measures should be introduced requiring suppliers to substantiate environmental claims about construction products by producing EPDS.
- Circular economy statements and pre-demolition audits -statements and audits which take into account adaption and re-use of existing buildings and include whole life carbon assessments of new-build v retrofit, should form part of planning applications.
- Use of timber in construction - a coherent government policy on afforestation to meet the demand for domestic timber for construction needs to be developed and further research in the use of structural timber should be undertaken.
Comment
Achieving net-zero carbon emissions for new buildings is a key priority for the government and for the industry. Whether the Carbon Emissions (Buildings) Bill makes it through the Parliamentary process remains to be seen, but the growing awareness that embodied carbons need to be controlled and reduced points to the need for government action. After all, according to the UKGBC, embodied carbon emissions from the construction, refurbishment and demolition of buildings exceed the total of the aviation and shipping industries combined.
