Demolition carbon, site waste and the pre-redevelopment audit
The quantities in a pre-redevelopment audit drive the reuse percentages you commit to and the pre-construction demolition carbon figure. Record them while the building is still standing, and keep the evidence trail for the condition.
A demolition carbon site waste audit is worth more than its reporting value, because the quantities it records drive two separate planning commitments at once. The reuse and recycling percentages you offer come from it. So does the pre-construction demolition carbon figure in a whole life carbon assessment. Get the audit done badly and both numbers are guesses, which is exactly what an officer will say when the application is checked.
Do it before the demolition contractor is appointed. Once the building is down, the information is gone.
What the audit records and when
A pre-redevelopment audit is a survey of what is in the existing building and on the site, expressed as quantities by material. It covers the structure, the facade, internal fit-out, services, external works and, where relevant, the excavation material the scheme will generate.
The useful version records four things for each material stream: quantity, condition, likely route, and the barrier to reuse. A steel frame with full mill certification and a steel frame without are the same tonnage and a different proposition entirely.
Timing is the part people get wrong. The audit should be done while the building is standing and accessible, before the planning application if the authority expects the audit as submission material, and always before any strip-out. In London, the Greater London Authority's circular economy policy expects referable schemes to submit this material with the application, so it sits on the critical path rather than in the post-permission pile.
A Pre-redevelopment Audit can be structured from a PlanScope draft and then completed with the survey data, which keeps the reporting consistent with whatever the authority asked for.
Recovery and reuse rates worth committing to
Percentages offered in a planning statement become conditions, and conditions get discharged against evidence. So offer numbers you can deliver.
The Greater London Authority's circular economy guidance sets benchmarks for the proportion of demolition and excavation material to be reused, recycled or recovered, and for recycled content in new construction. Those benchmarks are high, in the region of 95 per cent for demolition and excavation material, and they are achievable mainly because crushing concrete for sub-base counts. Check the current guidance for the figures before quoting any of them.
What separates a credible commitment from an aspirational one:
- Reuse in situ, such as crushing concrete on site for piling mats and sub-base, which avoids transport entirely.
- Reuse off site in a named project or through a reclamation route, which needs a receiving destination.
- Recycling into a lower-value product, which is where most tonnage actually goes.
- Energy recovery, which counts towards diversion from landfill and not towards circularity.
Be honest about the hierarchy. A statement claiming high reuse when the plan is crushing and recycling will be read by someone who knows the difference.
Hazardous material and the survey sequence
The sequence here is not negotiable and it is the thing most likely to delay a start on site.
- Commission a refurbishment and demolition asbestos survey under the Control of Asbestos Regulations 2012. This is intrusive and destructive, and it must cover every area the works will disturb.
- Identify other deleterious materials: lead paint, sealants containing polychlorinated biphenyls, insulation containing ozone-depleting substances, fluorescent tubes, and refrigerants in cooling plant.
- Arrange a bat and nesting bird inspection of the building before demolition, because roosts and active nests are protected and the survey windows are seasonal. Bat work requires a suitably licensed ecologist under the Wildlife and Countryside Act 1981 and the Conservation of Habitats and Species Regulations 2017, and a mitigation licence takes time to obtain.
- Record invasive species, Japanese knotweed in particular, because the soil it occupies becomes controlled waste with a restricted disposal route.
Licensable asbestos work requires a licensed contractor and advance notification to the Health and Safety Executive. Build that notice period into the programme rather than discovering it in week one.
Carbon accounting for the demolition phase
Whole life carbon assessment to the RICS methodology reports pre-construction demolition and site preparation separately from the construction stage, which means the demolition figure is visible and comparable.
Three inputs dominate it. The tonnage of material removed from site. The transport distance to the receiving facility. And the amount of material processed on site rather than carted away.
That third input is the one a design team can actually influence after the audit. Crushing on site removes vehicle movements in both directions, which cuts transport carbon and construction traffic at the same time, and it usually helps the construction traffic management case as well.
| Decision | Carbon effect | Planning effect |
|---|---|---|
| Crush and reuse concrete on site | Removes export and import movements | Fewer vehicle movements to assess |
| Retain substructure or basement box | Avoids demolition and new concrete | Constrains layout and levels |
| Retain the frame and re-clad | Largest single saving available | Changes the application from new build to alteration |
| Export all material to a recycling facility | Transport-dominated figure | Heavier traffic management requirement |
The retention options belong in the discussion early, because national policy and many local plans now expect applicants to justify demolition rather than assume it. A Whole Life Carbon Assessment following the RICS approach is the document that makes or breaks that justification, and councils normally expect a suitably qualified author, with professional review strongly advised.
Conditions on waste and reporting
Expect three families of condition on a scheme involving demolition.
A condition requiring a site waste management plan, or a waste management strategy, to be submitted and approved before demolition starts. The Site Waste Management Plans Regulations 2008 were revoked in England, so the document now sits in a condition or a local policy rather than in regulations, and the content expected varies between authorities.
A condition requiring the approved reuse and recycling rates to be achieved, with evidence at completion.
A condition requiring a demolition method statement and, separately, a construction traffic management plan covering the demolition phase.
Demolition also brings obligations outside planning. Prior approval for the method of demolition and site restoration may be required under the General Permitted Development Order, and a notice to the local authority under the Building Act 1984 is a separate requirement handled by building control.
Contractor obligations and the building contract
Planning conditions bind the developer. Delivery depends on the contractor, so the obligations have to appear in the contract documents, with the audit as an appendix.
The clauses that matter: a requirement to achieve the stated diversion rates, a requirement to keep and provide waste transfer and consignment notes, a requirement to notify before any material leaves site for a route other than the one assumed, and a requirement to report monthly against the audit quantities.
Waste duty of care under the Environmental Protection Act 1990 and the waste hierarchy duty under the Waste (England and Wales) Regulations 2011 sit on the parties regardless of what the contract says. The contract decides who assembles the evidence.
Evidence at completion
Discharging the condition means a reconciliation, not an assertion. The authority wants the audit quantities on one side, the actual tonnages and destinations on the other, and an explanation of the variances.
Keep waste transfer notes and hazardous waste consignment notes through the build. Record which loads were reused on site, because material that never leaves site has no transfer note and is therefore invisible unless you log it separately. That omission is the most common reason a Site Waste Management Plan condition cannot be discharged on the evidence available.
Carbon reporting at outline stage raises the same problem one step earlier, where quantities are indicative rather than measured, as set out in carbon reporting in an outline application.
PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval. For specialist technical reports, qualified professional input may be required.
Frequently asked questions
When should a pre-redevelopment audit be carried out?
While the building is standing and accessible, before any strip-out, and before the application where the authority expects the audit as submission material. In London the Greater London Authority's circular economy policy expects it with referable applications, so it belongs on the critical path rather than in post-permission work.
What reuse rates should a scheme commit to?
Only rates you can evidence. The Greater London Authority's circular economy guidance sets high benchmarks for demolition and excavation material, in the region of 95 per cent reused, recycled or recovered, achievable largely because crushing concrete for sub-base counts. Check the current guidance before quoting any figure in a statement.
What surveys are needed before demolition?
A refurbishment and demolition asbestos survey under the Control of Asbestos Regulations 2012, an assessment of other deleterious materials, and a bat and nesting bird inspection. Bat work needs a suitably licensed ecologist, and a mitigation licence takes time, so the ecology sequence usually sets the earliest start date.
Are site waste management plans still a legal requirement?
Not under the Site Waste Management Plans Regulations 2008, which were revoked in England. The document now appears through a planning condition or local policy, with content varying between authorities. The waste hierarchy duty under the Waste (England and Wales) Regulations 2011 and duty of care still apply regardless.
Why does on-site reuse cause problems at condition discharge?
Because material that never leaves the site has no waste transfer note, so it is invisible in the paperwork unless logged separately. Keep a record of loads crushed and reused on site alongside the transfer and consignment notes, or the reconciliation against the audit quantities will not add up.
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.