Last week, the Environmental Audit Committee (EAC) shared the findings of their inquiry into the sustainability of the built environment in their report, Building to net zero: costing carbon in construction. The report sets out clear actions and recommendations for government to ensure the sector is on the path to net zero. The RIBA called on the committee to undertake this inquiry – with almost 40% of carbon emissions stemming from the built environment – the sector has a key role to play in addressing the climate emergency. We provided both written and oral evidence to the committee highlighting the actions needed to create a more sustainable built environment.
The report lays out the government’s inaction on embodied carbon stating, “if the UK continues to drag its feet on embodied carbon, it will not meet net zero or its carbon budgets”. It also highlights the lack of incentives to develop or use low carbon materials and points to insufficient evidence that the government is doing enough to prioritise the retrofit or reuse of existing buildings.
Echoing our evidence, the report suggests that the government should introduce a mandatory requirement to undertake whole life carbon assessments for buildings. This requirement should be set within building regulations and the planning system. Following the introduction of whole life carbon assessments, the report suggests the government should develop progressively increasing carbon targets for buildings, to match the pathway to net zero.
Those familiar with the RIBA 2030 Climate Challenge will be aware that we have been highlighting the importance of measuring embodied carbon and reducing whole life carbon as key to reaching net zero. It is positive to see MPs acknowledge this and call for the government to act.
One of the barriers to reducing embodied carbon is a lack of agreed methodology across the sector. However, the evidence supplied to the inquiry showed overwhelming support for the RICS Professional Statement on whole life carbon. While it was pointed out it is not perfect, the committee suggested it should be used in the absence of an approved UK national methodology – mirroring the RIBA position.
To ensure embodied and whole life carbon are considered through all stages of a project, the EAC recommend that the government should provide clear definitions of these terms in the National Model Design Code based on RIBA, Whole Life Carbon Network and LETI definitions.
What about materials? The report acknowledges the role timber can play in reducing the embodied carbon of a building. But notes the current ban on timber has had a detrimental effect on innovation in structural timber. We have been calling on the government to undertake further research into the use of structural timber within external walls to determine and quantify its performance when subjected to real fire loads. It’s positive to see the EAC support this too.
More widely, the committee noted that there is a lack of Environmental Product Declarations (EPDs) for a wide range of materials, and this was limiting developers’ ability to choose low carbon materials sourced in the UK. They suggested that the government should encourage the development of a centralised national database of EPDs. Positively, the RIBA is already making progress in this area and has been collaborating across the built environment to develop the Built Environment Carbon Database (BECD) for the UK. The database is envisioned to become the main source of carbon estimating and benchmarking for the UK construction sector and a practical instrument to support the decarbonisation of the built environment. Want to get involved? You can comment on the data structure until 24 June 2022.
Finally, the report references our policy of linking energy efficiency to stamp duty to drive retrofits in existing homes. However, the report falls short of recommending the government introduce this policy. We will continue to advocate for the use of taxation to stimulate a retrofit revolution.
The government will now consider these recommendations and will respond in due course. While we await the response, we will continue to lobby policymakers on behalf of architects to ensure that the built environment is at the forefront in addressing the climate emergency.