When are they required in London?
London Plan guidance identifies whole life-cycle carbon assessments under policy SI2 and circular economy statements under policy SI7 for developments referable to the Mayor. The circular economy guidance also recognises that boroughs can require statements for other development through their own policies. [1]
Westminster's current guidance and 2026 validation list extend requirements to specified redevelopment and retrofit projects. Do not assume that being below the Mayor's referral thresholds means no carbon or materials evidence is required locally. Equally, do not apply Westminster's triggers as if they were identical across London. [2] [3]
What does whole life-cycle carbon cover?
The assessment considers stages including product sourcing and construction, use, and the end of the building's life. The purpose is wider than the energy used to heat and operate the completed building. The GLA guidance links the carbon assessment to material quantities and the assumptions made about future reuse or disposal. [1]
Ask the assessor to explain the proposed building's significant carbon sources and how different design options have been compared. The report should identify its scope and assumptions clearly enough for the design team to understand the implications of retaining, replacing or specifying particular elements.
What does the circular economy statement cover?
It explains decisions about retaining existing buildings or elements, reducing material demand, reusing resources and designing for later adaptation or disassembly. The GLA guidance requires the relevant written information and supporting reporting material, rather than a generic statement that waste will be recycled. [1]
Westminster's Retrofit First guidance links these questions to early assessment of an existing building and the proposed extent of intervention. Its guidance should be used as a local requirement and design framework; suggested performance ambitions must not automatically be described as universal mandatory targets. [4] [2]
Who prepares and coordinates the work?
Use a competent carbon or sustainability specialist, with material quantities and design information supplied by the relevant designers and cost professionals. The GLA guidance expressly asks the two assessments to use the same bill of materials and consistent end-of-life assumptions. [1]
A useful appointment should identify who prepares the initial audit, who tests options, who maintains the material information and who updates the assessment after design changes. Avoid separate reports using different areas, structural schemes or demolition assumptions.
Does the work end at planning submission?
Not necessarily. The GLA guidance provides for post-construction reporting secured through the planning process. The project therefore needs a way to record what was actually procured and built, not only what was intended at application stage. [1]
The draft new London Plan remains under consultation until 15 October 2026 and may change future requirements. Keep current adopted policy and any emerging provisions separate, and recheck the applicable scope before commissioning an update. [5]