Pre-redevelopment audit content for material reuse

A pre redevelopment audit reuse case stands or falls on what the audit records before anything is taken down. The audit is a survey of the existing buildings and structures on a site that quantifies the materials in them, assesses what can be reused or recycled, and identifies what has to be removed as hazardous waste. Done at the right moment it produces evidence a planning authority can rely on. Done after the soft strip, it is a guess dressed up as a document.

The distinction that matters is between this audit and a site waste management plan. One looks at what exists now. The other manages what the construction process generates later.

What the audit records before demolition

The audit covers everything on the site that will be removed or altered: the building fabric, the structure, the services installations, fixtures and fittings, external works, hard landscaping and any plant.

For each element it should record the material type, an estimated quantity by mass or area, the condition, the fixing method, whether it can be removed without damage, and a proposed destination. That destination is the point of the exercise. Retained in situ, reused on site, reused off site, recycled, recovered or disposed of, in that order, following the waste hierarchy in the Waste (England and Wales) Regulations 2011.

The audit should also record what is worth keeping for reasons other than material value. Original joinery, stone, structural timber, cast iron and brick with lime mortar all have reuse potential that a standard demolition contract would destroy. On a building with any heritage interest, this overlaps with recording obligations, and the two surveys should be coordinated rather than run separately.

Timing is the constraint. The audit needs access to the building while it is intact, which means before the previous occupier's fit-out is stripped and before any enabling works.

Quantifying materials by type and mass

Quantities are where audits are weakest, because measuring a standing building is harder than measuring a design.

The workable method is to build the quantities from the survey information you have. Measured floor areas by element, construction build-ups taken from opening-up surveys or from record drawings, and standard densities for each material. State the basis for each figure and the confidence in it. A quantity derived from an opening-up survey at three locations is worth more than one derived from an assumption about a 1970s build-up, and the reader should be able to tell which is which.

Break the inventory down by material rather than by element for the reuse assessment, because reuse markets work by material. Concrete, brick, block, steel, aluminium, timber, glass, plasterboard, insulation, ceramics, asphalt and mineral fibre each have different destinations.

Where quantities cannot be established without destructive investigation that is not yet possible, say so, give a range, and state what would resolve it. Our note on the material inventory in a pre-redevelopment audit goes through the inventory structure in more detail.

Assessing reuse and recycling potential

Potential is not the same as likelihood, and an audit that reports theoretical recyclability for every material tells the reader nothing.

Assess each material against four practical questions. Can it be removed intact, given the fixings and the demolition sequence. Is there a market or an on-site use for it. Does reuse require testing, certification or a warranty that is available. And does the programme allow the extra time that careful deconstruction takes.

Structural steel is the clearest case. Reclaimed steel can be reused structurally where its properties are established by testing and a competent engineer accepts it, and the carbon saving is large. But it requires a deconstruction sequence rather than a demolition sequence, storage space, and a designer willing to work with non-standard sections. If any of those is missing, the honest answer in the audit is that reuse is not achievable on this project, with the reason given.

Brick reuse depends almost entirely on the mortar. Lime mortar allows cleaning and reuse. Cement mortar generally does not, and the bricks go to crushing.

Concrete is usually crushed for use as fill or aggregate on site, which is recovery rather than reuse, and the audit should not describe it as reuse.

Hazardous materials and their separation

The audit has to identify hazardous materials because they determine the demolition method, the cost and the waste classification.

Asbestos is the main one. A refurbishment and demolition survey under the Control of Asbestos Regulations 2012 is a legal requirement before demolition or refurbishment work that will disturb the fabric, and it is a separate specialist survey rather than something a materials audit can substitute for. Reference it, attach it, and make sure the removal sequence in the demolition plan follows it.

Other items to flag: lead paint and lead flashings, polychlorinated biphenyls in older sealants and capacitors, refrigerant gases in plant, fluorescent tubes and discharge lamps, contaminated made ground under slabs, fuel tanks and their surrounding soils, and treated timber.

Hazardous materials removed early and separately reduce the contamination of the rest of the waste stream, which is what makes the remaining materials recyclable at all.

Linking the audit to a circular economy case

Where the authority requires a circular economy statement, and London is the clearest example through the London Plan, the audit is the evidence base that statement relies on. The statement sets out targets and commitments. The audit says what is actually in the building.

Three links have to be made explicit in the documents. The tonnages in the audit have to reconcile with the tonnages in the Circular Economy Statement. The reuse commitments have to be ones the audit supports, not aspirations. And the carbon consequences of reuse decisions should feed into the whole life carbon work rather than sitting in a separate document with different numbers.

Authorities have become better at checking that reconciliation. An inconsistency between two of your own documents is the easiest objection for a consultee to make.

Timing relative to soft strip

Work backwards from the demolition programme.

The audit needs access while the building is intact and while the previous occupier's fit-out is still in place, because that fit-out contains recoverable materials. It needs to precede the asbestos survey's destructive elements only in the sense that the two should be planned together, since the asbestos survey opens up construction that the audit also wants to see.

Where the site is occupied until shortly before demolition, negotiate access for the survey team as a condition of the lease surrender. This is routinely forgotten and routinely regretted.

If the audit can only happen after the application is submitted, say so in the submission, explain the access constraint, and offer the audit by condition with the commitments secured in the meantime. Authorities accept that more readily than a document with invented quantities.

Evidence the council will ask for

Assemble the submission so an officer can check the chain from survey to commitment.

The package normally includes the audit report with the material inventory and quantities, the methodology and confidence statement, photographs of the elements surveyed, the asbestos survey reference, a reuse and recycling strategy with the destination for each material, the demolition method statement showing how the deconstruction sequence achieves it, and a monitoring proposal describing how actual tonnages will be reported after the works. Where a Site Waste Management Plan is also required, keep the two documents consistent on scope so that the audit covers the existing building and the plan covers construction arisings.

PlanScope can draft a Pre-redevelopment Audit structured to these headings, inserting its standard "to be confirmed" flag wherever quantities and survey findings are missing, rather than filling the gap with an estimated figure. The draft should be reviewed before submission, and the survey work itself has to be done by people on site.

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.