Pre-redevelopment audit: what to record before demolition

A pre redevelopment audit before demolition is only worth anything if it happens while the building is still intact. Once the soft strip has started, the quantities are guesses and the condition assessment is impossible, which turns the audit into a paper exercise that satisfies a validation requirement and delivers no reuse at all. The audit's job is to tell you what is in the building, how much of it there is, what condition it is in and where it goes next. Three of those four answers disappear the moment a contractor is on site.

So the sequence is: vacant possession, audit, then tender the demolition with the audit in the documents.

Why the audit comes before anything moves

Authorities ask for pre-redevelopment audits for two reasons. The first is waste: an audit is the only credible basis for a target expressed as a percentage of demolition arisings diverted from landfill. The second is carbon: reusing an existing element avoids the embodied carbon of its replacement, and that avoided carbon has to be quantified against something.

In London, the requirement is explicit for referable schemes, where the Mayor's circular economy policy expects a pre-redevelopment audit alongside the circular economy statement. Outside London, authorities with their own circular economy or sustainable construction policies increasingly ask for the same thing, and BREEAM awards credit for a pre-demolition audit regardless of local policy.

There is also a commercial reason that has nothing to do with planning. Reclaimed material has value, and an audit carried out before the demolition contract is let lets you retain that value instead of gifting it to the demolition contractor as part of their recovery margin.

Recording quantities, condition and location

The audit is a survey, so it needs to be done by someone walking the building with a measure, not by someone reading the as-built drawings.

For each material or element, record the quantity in a sensible unit, the location by floor and grid reference or room number, the condition, the method of fixing or jointing, and an assessment of whether it can be removed without destroying it. That last column is the one that turns a list into a plan. A brick skin in lime mortar can be taken down brick by brick. The same wall in cement mortar cannot, and recording that saves everyone a wasted conversation.

Photograph everything, with a scale in frame, and keep the photographs filed against the schedule entries. When a reuse buyer asks whether the roof slates are sound, a photograph answers in a minute.

Quantities should be measured rather than estimated wherever access allows. An audit that states 400 tonnes of concrete with no basis is useless for a target that will later be audited against waste transfer notes.

Materials with real reuse value

Not everything in a building is worth reclaiming, and an audit that implies otherwise loses credibility.

The materials that reliably find a second life are reclaimed brick in lime mortar, natural roof slate and clay tile, structural timber of reasonable section, stone, cast iron rainwater goods and radiators, good quality joinery and ironmongery, paving and kerbs, and architectural salvage items. Those have established markets and a buyer will usually collect.

Structural steel is the high-value prize and the hardest to realise. Reuse is technically possible where the material properties can be demonstrated by testing and the member has traceability, but the certification route is the constraint rather than the physics, and the decision has to be made early enough to allow careful dismantling with bolted connections cut rather than burned.

Concrete almost always goes to crushing rather than reuse, which is recycling rather than reuse and sits lower in the waste hierarchy. That is fine, but it should be described accurately. The waste hierarchy in the Waste (England and Wales) Regulations 2011 runs prevention, preparing for reuse, recycling, other recovery and then disposal, and an audit that calls crushing reuse will be marked down.

Mechanical and electrical plant is worth a specific look. Chillers and heat pumps contain refrigerant that must be recovered by a qualified person, and the global warming potential of what is in the existing plant matters both for the recovery obligation and, where equipment is retained, for the assessment of the new scheme, as set out in the discussion of refrigerant choice and global warming potential in planning.

Hazardous materials and the separate surveys

The reuse audit is not a hazardous materials survey and the two should not be conflated.

A refurbishment and demolition asbestos survey is required under the Control of Asbestos Regulations 2012 before demolition or major refurbishment, and it is intrusive by design. It has to be carried out by a competent surveyor and it has to cover the parts of the structure that the reuse audit cannot reach. Commission both and sequence them so the asbestos survey informs the reuse schedule rather than contradicting it.

Beyond asbestos, look for lead paint on joinery and metalwork, polychlorinated biphenyls in older sealants and electrical equipment, ozone-depleting substances and fluorinated gases in refrigeration and fire suppression systems, fluorescent tubes and other electrical equipment falling under the waste electrical regime, and reinforced autoclaved aerated concrete planks in buildings of the relevant era.

Each of those changes the reuse answer. Lead-painted joinery can be reclaimed, but the market narrows and the stripping cost rises. Material with bonded asbestos contamination is not reclaimable at all.

Record what you find and record where you looked and could not get access, because an unqualified audit invites a request for further information.

Routes to reuse on site and off site

On-site reuse is worth more than off-site reuse, in carbon terms and in money, because it avoids transport and avoids a buyer's margin.

1. Identify elements that can stay in place, which is the highest form of reuse and the one most often overlooked once a demolition decision has been taken.
2. Identify material that can be reused on site in the new build, such as crushed concrete as sub-base, reclaimed brick in boundary walls or landscape features, or stone in new facing work.
3. Identify material with an established off-site market and establish the buyer before demolition starts.
4. Identify material for recycling, and specify the processing route.
5. Identify the residue for recovery or disposal, with a reason.

Step two needs the design team to be engaged while the audit is live. Reclaimed brick specified in the landscape package six months after the demolition contractor has sold it is a missed opportunity that appears in the carbon assessment as a loss.

Storage is the practical blocker. Material reclaimed for reuse later in the programme needs a compound, and on a tight site that space does not exist. Where it does not, the honest answer in the audit is that the material will go to an off-site reclaim market, with the buyer named.

Feeding the audit into the waste targets

The audit's output becomes the baseline for the diversion target. In London, the policy expectation for referable schemes is that at least 95 per cent of demolition and excavation waste is reused, recycled or recovered, and similar figures appear in local policies elsewhere.

Reporting against that target means reconciling the audit against waste transfer notes and weighbridge tickets at the end of the job. Set the reporting format up at audit stage, with the same material categories in both, or the reconciliation becomes a manual exercise nobody has budgeted for.

The audit also feeds the carbon work. Avoided embodied carbon from reuse and the carbon cost of processing both appear in the whole life carbon assessment, and the audit quantities are the inputs. An assessment built on estimated demolition quantities carries a wide uncertainty band that a reviewer will notice.

Where the authority asks for a broader sustainability narrative, the audit findings belong in the sustainability statement rather than sitting in an appendix nobody reads.

Timing it around the demolition contract

The order of operations that works, and the one that most schemes get wrong, is this.

Obtain vacant possession. Commission the reuse audit and the asbestos survey together, with the audit team given access before any strip out. Produce the audit schedule. Put the schedule into the demolition tender documents with the reuse requirements written as obligations rather than aspirations. Let the contract, with a clause allocating the value of reclaimed material and a reporting duty. Then start on site.

If demolition is already under way, say so in the audit and record what has been lost. An honest partial audit with a stated scope limitation is defensible. A full audit presented as complete when the building was half stripped is not, and reviewers can tell from the photographs.

What the pre-redevelopment audit covers section by section is set out on its report page. 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, and an asbestos refurbishment and demolition survey must be carried out by a competent surveyor. You can start from the site postcode to see which reports a demolition and redevelopment scheme is likely to need.