CIBSE welcomes the Government’s recognition that whole-life carbon assessments will play an important role in decarbonising the UK’s buildings. However, we are disappointed that it has rejected the Environmental Audit Committee’s recommendation to introduce mandatory whole-life carbon assessments for major developments, instead indicating that it intends to rely on a voluntary approach to carbon accounting.
Whole-life carbon assessments measure the total emissions associated with a building across its lifecycle. The methodologies, standards and professional expertise required to undertake these assessments are already well established across the sector. Making carbon accounting voluntary risks ignoring this existing capability and undermines the Government’s own legal commitment for the UK economy to achieve net zero by 2050.
The Government also suggests that emissions increases in one part of the economy could be balanced by additional reductions or removals elsewhere in order to meet carbon budget limits. In practice, this risks creating a regulatory loophole whilst maintaining the status quo rather than delivering the sustained cross-sectoral reductions required to align with the UK’s net-zero trajectory.
Through the Part Z initiative, industry has already proposed a practical pathway through the introduction of a new regulatory requirement within Building Regulations. This would introduce mandatory whole-life carbon assessments first, followed by embodied carbon limits once sufficient data has been gathered.
Significant progress has already been made in developing the evidence base needed to support regulation. Initiatives such as the Built Environment Carbon Database and the UK Net Zero Carbon Buildings Standard, alongside growing industry datasets, are rapidly improving understanding of embodied carbon across building types. Recent analysis produced with industry partners following the Embodied Carbon Summit 2025 also demonstrates strong sector consensus on the need for a clear national framework.
Many countries have already introduced mandatory whole-life carbon assessment and embodied carbon limits. The UK risks falling behind international best practice unless it provides a clear regulatory signal.
We therefore urge the Government to work with industry to establish a clear timetable for mandatory whole-life carbon assessments for buildings, alongside a pathway to future embodied carbon limits.
To read the Government's Response to the report of the Environmental Audit Committee click HERE