Whole life carbon or circular economy: two different asks
A whole life carbon assessment produces numbers and a circular economy statement produces commitments. How they overlap and where reviewers find contradictions.
A whole life carbon or circular economy statement question usually arrives as a validation query, and the two documents are not alternatives. A whole life carbon assessment quantifies emissions across the life cycle of the building in kilograms of carbon dioxide equivalent. A circular economy statement commits to how materials are sourced, kept in use and recovered. One produces numbers, the other produces commitments, and a referable scheme in London needs both.
The documents overlap in their evidence base, which is where the contradictions creep in.
What a whole life carbon assessment calculates
A whole life carbon assessment follows the life cycle stages in the European standard for assessing the sustainability performance of buildings, and in the UK the method practitioners work to is the RICS professional standard on whole life carbon assessment, now in its second edition.
The assessment reports emissions by module. Product stage covers raw material supply, transport and manufacture. Construction process covers transport to site and the construction and installation work. The use stage covers maintenance, repair, replacement and refurbishment alongside operational energy and water. End of life covers deconstruction, transport, waste processing and disposal. A separate reporting category covers benefits and loads beyond the system boundary, which is where reuse and recovery credits sit.
Results are normalised, usually per square metre of gross internal area, so schemes can be compared against benchmarks. The Greater London Authority requires an assessment for referable applications and expects reporting on its own template, with a post-construction update once the building is built.
The thing to watch is the system boundary. An assessment that excludes substructure, or that treats a retained frame as free, produces a number that cannot be compared with anything. Ask what was included before you read the headline figure. The report sits alongside the Whole Life Carbon Assessment page for the detail on scope and inputs.
What a circular economy statement commits to
A circular economy statement is a commitment document. London Plan policy requires one for referable applications, and the Greater London Authority publishes guidance on what it should contain.
The content is organised around a set of principles rather than a calculation. Designing out waste at source. Designing for longevity, so the building lasts. Designing for adaptability, so it can change use without being demolished. Designing for disassembly, so components can be taken apart and reused. Using reclaimed and recycled materials. And planning the end of life rather than leaving it to a future demolition contractor.
The evidence a reviewer looks for includes a bill of materials setting out quantities by material type, recycled and reclaimed content, a strategy for construction and demolition waste with diversion targets, a commitment to specific reuse opportunities on site, and an end-of-life strategy. Check the current Greater London Authority guidance for the target figures, because they have been revised and a statement written against superseded targets will be queried.
Where existing buildings are being removed, a Pre-redevelopment Audit identifies what can be reclaimed, and that audit is the evidential spine of the statement. A circular economy statement that proposes reuse with no audit behind it is a list of intentions.
Life cycle modules and their boundaries
The clearest way to see the difference is to map each document onto the life cycle.
| Life cycle stage | Whole life carbon assessment | Circular economy statement |
|---|---|---|
| Product and construction | Quantified emissions from materials and site work | Material sourcing, recycled and reclaimed content |
| Use | Quantified maintenance, replacement and operational emissions | Longevity, adaptability and maintenance strategy |
| End of life | Quantified deconstruction, transport and disposal emissions | Disassembly strategy and end-of-life plan |
| Beyond the boundary | Reported reuse and recovery credits separately | Committed reuse and recovery routes |
The carbon assessment measures the consequence. The circular economy statement describes the decision. Treat them as one evidence base with two outputs and the contradictions disappear.
Reuse, disassembly and material passports
Three mechanisms recur in circular economy statements and each has a carbon consequence that should appear in the assessment.
Reuse of existing structure is the big one. Retaining a frame, a basement or a substructure avoids the product stage emissions for those elements, and on a commercial redevelopment that can dominate the whole life figure. Where a statement commits to retention, the carbon assessment should show the saving, and where it does not, ask why.
Design for disassembly means bolted rather than welded connections, mechanical fixings rather than adhesives, demountable partitions and services that can be replaced without demolishing finishes. The carbon benefit mostly appears in the end-of-life modules and in the beyond-boundary category, which is why it is often invisible in the headline number. Say so in the statement rather than claiming a saving the assessment does not show.
Material passports record what is in the building and where, so a future owner can reclaim it. They are a commitment with no immediate carbon effect, easy to promise and easy to forget. If you offer one, say who will hold it and how it will be updated.
Where demolition is proposed rather than retention, the consent position needs checking as well as the carbon case, and our note on demolition prior notification or planning permission sets out which route applies.
Where the two documents must agree
Five points of contact, and each one is a place a reviewer will look for a contradiction.
- The bill of materials in the circular economy statement should reconcile with the quantities in the carbon assessment
- Retention commitments should produce a visible reduction in the product stage of the assessment
- Recycled content claimed in the statement should be reflected in the emission factors used
- The pre-redevelopment audit's reclaimed materials should appear in both documents with the same quantities
- End-of-life assumptions in the assessment should match the disassembly strategy in the statement
The practical way to achieve this is to have one person coordinate both documents even where two consultants produce them. The common failure is a sustainability consultant writing the circular economy statement from a template while a separate carbon consultant models the scheme as drawn, with nobody reconciling the two.
Reporting after completion
Both regimes extend past the decision notice. The carbon assessment has a post-construction reporting stage, which compares the as-built figure against the figure submitted at application, and the circular economy statement has a post-completion report on what was actually achieved.
Those obligations are usually secured by condition or by a planning obligation, and they land on whoever owns the development at the time. Two consequences for a developer. The data has to be collected during construction, which means the contract has to require it from the main contractor and the supply chain. And a scheme sold before completion needs the obligation dealt with in the sale, because the purchaser inherits a reporting duty they may not have priced.
Set up the data collection at tender stage. Retrofitting a bill of materials from invoices after practical completion is possible and nobody enjoys it.
Which schemes need both
In London, referable applications need both, and some boroughs ask for a carbon assessment below the referral threshold through their own local plan policies.
Outside London the position is patchier and moving. There is no national requirement for a whole life carbon assessment at the time of writing, and proposals for a national regulation on embodied carbon have been discussed without being adopted. Check the adopted local plan and the validation checklist for the authority, because a growing number of authorities now require an embodied carbon assessment for major development through policy rather than through national rules.
The honest advice for a developer outside London is to do the carbon assessment early anyway, on a major scheme, for a reason that has nothing to do with validation. It changes design decisions on frame material, on retention and on substructure while those decisions are still open, and it is worthless as a design tool once the scheme is fixed. The Circular Economy Statement can follow the design, but the carbon work should lead it.
PlanScope can draft both documents as structured first drafts, with the policy framing in place and flags where your quantities and emission factors belong, then you can send them for professional review. Councils expect a suitably qualified author for whole life carbon work, so treat the draft as the frame rather than the finished assessment. PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval.
This is general guidance, not legal advice. Check the position with your local planning authority or a qualified professional before relying on it.
Frequently asked questions
Is a circular economy statement an alternative to a whole life carbon assessment?
No. They answer different questions and a referable scheme in London needs both. The carbon assessment quantifies emissions across the life cycle modules in kilograms of carbon dioxide equivalent, normally per square metre of gross internal area. The circular economy statement sets out commitments on sourcing, longevity, adaptability, disassembly and end of life.
What should I check first in a whole life carbon assessment?
The system boundary. An assessment that excludes substructure, or that treats a retained frame as carrying no burden, produces a figure that cannot be compared with a benchmark or with another scheme. Establish what was included before reading the headline number, then check which emission factors and which service life assumptions were used.
Do I need a pre-redevelopment audit?
If you are removing existing buildings and claiming reuse, yes in substance. The audit identifies what can be reclaimed and in what quantity, and it is the evidence behind the reuse commitments in a circular economy statement. A statement promising reuse without an audit behind it reads as a list of intentions and will be queried.
Are these documents required outside London?
Not by national rules at present. There is no national requirement for a whole life carbon assessment, and proposals for a national embodied carbon regulation have been discussed without adoption. A growing number of authorities require an embodied carbon assessment for major development through local plan policy, so check the adopted plan and the validation checklist.
What happens after the planning decision?
Both regimes extend past it. The carbon assessment has a post-construction reporting stage comparing as-built against submitted figures, and the circular economy statement has a post-completion report. These are usually secured by condition or obligation, so the main contract has to require the data and a sale before completion must deal with the duty.
Sources and further reading
This article is general guidance about the planning system in England and, where stated, the rest of the UK. It is not legal or professional advice. Check your local planning authority’s validation requirements and take professional advice for your specific site.