Institution of Structural Engineers SBE0080
The Institution of Structural Engineers welcomes the opportunity to submit evidence to the House of Commons inquiry. The built environment is responsible for 38% of global carbon emissions, and the use of steel, concrete, timber, brick, and other structural materials is responsible for around 10% of global carbon emissions1.
The institution’s response to this inquiry has been led by our Climate Emergency Task Group, who are at the forefront of industry change to decarbonise the built environment. We are raising the standards for practising engineers, and helping our members with new guidance to enable them to respond to the climate emergency.
Our work is coordinated and aligned with that of other professional institutions, including RIBA and RICS, and we are heavily involved in pan-industry initiatives such as the CIC climate action plan, the UKGBC whole life net zero roadmap project, and the work of the National Engineering Policy Centre through the RAEng.
The Committee on Climate Change report advocates for “the assessment and benchmarking of whole-life carbon in buildings”, as part of wider policy proposals to minimise whole life carbon in the built environment. The report also advocates for specific measures such as increasing the use of timber in construction, but it should be noted that single actions like this are not guaranteed to lead to lower carbon buildings. There is currently no UK government legislation that ensures the minimisation of whole life carbon in the built environment.
Whole life carbon is split primarily into two parts: embodied carbon (emissions due to the construction, maintenance and demolition of an asset), and operational carbon (emissions due to the use of heat, power and water). Both must be assessed, and the total reduced, in order to minimise the whole life carbon footprint of a project. Operational carbon is already partially regulated through Building Regulations Part L, and the Future Homes Standard aims to improve on this.
Embodied carbon is not captured anywhere within building regulations, nor is it covered under the Future Homes Standard.
There is an urgent need to legislate both the requirement to undertake embodied carbon assessments, and meet agreed limits, as part of all construction projects including housing.
The only way to adequately assess the embodied carbon emissions relating to the entire life cycle of an asset is to undertake a whole life carbon assessment. This could be implemented almost immediately, with much of the industry already upskilling in line with the well-established standards and methods overleaf. The introduction of carbon targets, limits, or taxation, should then be introduced by 2025 with regular tightening of restrictions during the subsequent years. This will incentivise lower-carbon design, as well as investment into lower-carbon materials.
Carbon accounting standards and assessment methods are well-established already across the building industry. There is a set of well-aligned standards, both international (e.g. ISO 14040, PAS 2050) and British (e.g. BS EN 15804 and 15978). These standards are then put into practice via the RICS Professional Statement, Whole life carbon assessment for the built environment – which is methodology that is followed across the UK today.
These documents are consistent, and have been used for some years now. They account for the whole life cycle (production, transport, installation, use, replacement, dismantling etc.), including both embodied and operational carbon. Because a whole life carbon assessment uses quantities as well as type of material, it is a simple way to identify the most carbon-efficient configuration of materials for any given project brief.
Whole life carbon assessments follow well-established methodologies, and the industry is ready for legislation requiring their implementation on all projects.
The IStructE, other professional institutions (e.g. RIBA, CIBSE, ICE), and cross-industry bodies (e.g. CIC, LETI, UKGBC) have produced their own guidance for their members, again referencing the same standards. We have been working hard to embed these methodologies into standard practice in the UK in recent years, and many of our members already work on projects where clients have set carbon targets for them (often based on the LETI targets).
The building and construction sector uses half of all new resources and generates more than a third of all waste in the EU. Circular economy principles (which have reuse and refurbishment at their core) reduce carbon and waste – the reuse of an existing building can reduce the embodied carbon of a construction project by as much as half. Other co-benefits include the avoidance of ecological damage due to resource extraction, and job-creation in a market which uses less material but typically requires more labour.
At the moment, there are few legislated incentives to prioritise circular economy thinking and reuse – in fact the recent change to permitted development rights (allowing some demolition and rebuild to bypass normal planning applications) encourages the opposite behaviour. Renewal and reuse of existing buildings must become a core focus of any regeneration strategy, creating jobs and buildings with the lowest carbon footprint. The circularity requirements included in the latest London plan is exemplary of this approach, and should be considered for wider adoption across the UK.
The introduction of mandatory carbon assessments and carbon limits will incentivise reuse of existing buildings. Legislation for circularity requirements could boost this, and eliminating VAT on retrofit projects would provide a financial incentive to accompany this behaviour.
The UK construction industry’s approach to embodied carbon is rapidly maturing, with established carbon accounting methodologies, and professional bodies providing the training required to upskill their membership in this area.
Legislating a requirement to undertake whole life carbon assessments on all construction projects will increase the uptake of carbon assessments across the industry. Legislating for carbon limits or taxes will incentivise clients and design teams to design for the lowest carbon solutions. Finally, policy review to encourage reuse and circularity provides the quickest route to low carbon construction.
The IStructE is the world's largest membership organisation dedicated to structural engineering, representing 20,000 structural engineers in the UK, and a further 10,000 across 116 other countries worldwide. We uphold rigorous technical standards that drive safety and innovation, supporting communities of technical excellence, and promoting the value we bring to society as creative problem solvers and the guardians of public safety.
As the professionals charged with the efficient use of structural materials, the Institution has been working tirelessly since 2019 to put sustainability on a par with safety. We have reviewed our code of conduct, our education standards, and our requirements for attaining Chartered Member status with us – arguably the most widely respected mark of competence in the structural engineering profession – as well as providing our membership with the tools needed to respond to a world of Net Zero ambitions.
 Global Status Report, 2020, GABC, https://globalabc.org/news/launched-2020-global-status-report-buildings-and-construction
 UK housing: Fit for the future?, 2019, CCC, https://d423d1558e1d71897434.b-cdn.net/wp-content/uploads/2019/02/UK-housing-Fit-for-the-future-CCC-2019.pdf
 Embodied Carbon Primer, 2020, LETI, https://www.leti.london/ecp
 Buildings as material banks, https://www.bamb2020.eu/
 Vertical extensions: technical challenges and carbon impact, 2020, IStructE https://www.istructe.org/journal/volumes/volume-99-(2021)/issue-5/vertical-extensions-technical-challenges-carbon/