Costing a pre-redevelopment audit for reclaimed materials
A pre-redevelopment audit prices on access rather than floor area. Record drawings, an existing asbestos survey and an empty building cut the cost sharply.
A pre-redevelopment audit prices mostly on access, not on floor area. Two buildings of identical size can differ by a factor of three in survey cost because one is empty with the ceilings already down and the other is occupied, tenanted and fully fitted out. Anyone budgeting for the audit from a rate per square metre will be wrong in one direction or the other, and the direction is usually the expensive one.
The audit itself is a record of what is in the existing buildings, in what quantity and condition, and where each material stream can realistically go. In London it is the evidence base for a Circular Economy Statement on referable applications, and authorities outside London increasingly ask for the same work under their own waste and sustainability policies.
What the audit records
A Pre-redevelopment Audit covers the existing buildings and structures, element by element, before anything is taken down. The output is a quantified schedule rather than a narrative.
- Structural elements: frame type, steel sections and grades where known, concrete, masonry, timber.
- Envelope: facing brick, stone, cladding panels, curtain walling, windows, roof coverings.
- Internal components with resale or reuse value: raised access floors, suspended ceiling grid and tiles, doors and ironmongery, sanitaryware, light fittings, mechanical plant.
- Architectural features: stair balustrades, joinery, decorative stone, period fittings.
- Hazardous materials identified separately, because they drive the demolition method.
Each line carries a quantity, a condition assessment and a destination: reuse on site, reuse off site, recycling, recovery or disposal. That hierarchy mirrors the duty in the Waste (England and Wales) Regulations 2011 to apply the waste hierarchy, which is the legal spine of the whole exercise.
Surveying in situ, and what drives the cost
The survey is where the money goes, and the variables are mostly about getting to the material.
| Driver | Effect on cost |
|---|---|
| Occupancy | Occupied buildings need out of hours access, escorts and multiple visits |
| Fit-out in place | Finishes conceal the structure, so quantities become estimates unless opened up |
| Intrusive opening up | Each opening needs permission, making good, and sometimes scaffold or access equipment |
| Existing information | Record drawings, an asbestos register or a recent condition survey remove whole days of work |
| Number of buildings | Each structure needs its own schedule, so a site with six small buildings costs more than one large one |
| Material testing | Sampling and laboratory testing of steel, brick or timber is a separate line altogether |
| Height and access | Roof coverings and cladding above three storeys need access provision |
The single biggest saving is information you already own. Before commissioning, gather record drawings, the asbestos refurbishment and demolition survey required under the Control of Asbestos Regulations 2012, any structural appraisal, the plant schedules and the original specification. Handing those over at the start turns an investigation into a verification.
The second biggest saving is sequencing. Where the asbestos survey is being done anyway, running the audit survey alongside it shares the access, the scaffold and the escort costs.
Quantifying reuse, recycling and disposal
Quantities have to be expressed in units the demolition contractor and the waste carrier recognise, which usually means tonnes by material stream with a parallel schedule of components by number.
The reuse assessment is the part that needs judgement. A material is reusable if there is a route for it, a buyer or an on-site application, and a specification it can meet. Rubble crushed for sub-base on the same site is near certain. Facing brick depends entirely on the mortar: lime mortar gives you salvageable brick, modern cement mortar usually does not.
Where reuse off site is claimed, the audit should name the route in general terms rather than assert a market exists. An authority reading a claim of 80 per cent reuse with no destination identified will treat the figure as aspiration.
How it feeds the Circular Economy Statement
The audit is the input. A Circular Economy Statement is the output document that sets out how the scheme applies circular economy principles, including retention, reuse, design for disassembly and the end of life position for the new building.
Three practical points follow from that relationship. The audit has to be done early enough to influence the scheme, because its most valuable finding is often that part of the existing structure should be retained. Its quantities have to match the ones in the statement and in any Whole Life Carbon Assessment, since all three are read together. And the demolition stage figures in the carbon assessment come from the audit, so an audit done after the carbon assessment forces a revision.
A Site Waste Management Plan then carries the construction phase arrangements. The audit tells you what will arise; the plan says how it will be managed.
An illustrative example
This example is illustrative. A 1970s office block and two single storey outbuildings are to be replaced. The office is vacant, the ceilings are intact, and record drawings exist for the frame.
The audit survey takes two days on site because the building is empty and the drawings confirm the steel grid. The outbuildings take half a day each, disproportionate to their size, because nothing is recorded about them. Intrusive opening up is limited to four locations to confirm floor build-up and cladding fixings.
The findings change the scheme. The steel frame is in good condition and in standard sections, and retaining two bays of it avoids a significant volume of new steel. The facing brick to the outbuildings is in cement mortar and is written off as hardcore. The raised access floor, roughly 2,000 panels, has an identified off site reuse route.
Retaining the frame was worth more than every other finding combined, and it was only possible because the audit happened before the structural design was fixed.
Storage, handling and testing
Keeping material has a cost that reuse claims often ignore. Double handling, space on a constrained site, protection from weather and damage, insurance and the risk of loss all sit against the saving.
That calculation usually favours reuse in three situations: where the material goes straight back into the same building with no intermediate storage, where it has high value per tonne such as stone or architectural metalwork, or where the material would otherwise attract a high disposal cost.
Testing is the other hidden line. Reclaimed structural steel needs its properties established before it can be designed with, reclaimed brick needs durability and frost resistance confirmed for external use, and reclaimed timber needs grading. Budget for testing where the material is going into a structural or weather exposed application, and treat untested reclaimed material as suitable for non-structural use only.
Where the audit pays for itself
Three findings recover the cost of a typical audit on their own: a structure or substructure worth retaining, a high value facing material worth salvaging, and an accurate hazardous material picture that stops the demolition contractor pricing in uncertainty.
PlanScope drafts a Pre-redevelopment Audit structured the way reviewers read it, with "TO BE CONFIRMED" flags wherever quantities have to come from the survey, so the surveyor's time goes on the site rather than on the document. See PlanScope pricing for the one free report, the single report price and the Professional tier for practices producing these regularly.
This is general guidance, not legal advice; check the position with your local planning authority or a qualified professional before relying on it. PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval.
Frequently asked questions
What is a pre-redevelopment audit?
A quantified record of the materials and components in existing buildings before demolition, with a condition assessment and a destination for each stream: reuse on site, reuse off site, recycling, recovery or disposal. In London it is the evidence base for a Circular Economy Statement, and other authorities ask for equivalent work under their own waste policies.
What makes an audit expensive?
Access rather than size. Occupied buildings needing escorted out of hours visits, fit-out concealing the structure, intrusive opening up with making good, multiple small buildings and material testing all add cost. Supplying record drawings, the asbestos refurbishment and demolition survey and any structural appraisal removes much of it.
When should the audit be carried out?
Before the structural design is fixed. Its most valuable finding is usually that part of the existing structure or substructure should be retained, and that only helps if the design can still respond. An audit produced after the whole life carbon assessment also forces that assessment to be revised.
Can reclaimed steel be reused structurally?
Yes, where its properties have been established by testing and the designer is satisfied it meets the requirements for the application. Untested reclaimed material should be treated as suitable for non-structural use only. The same applies to brick, which needs durability and frost resistance confirmed before external use, and to timber, which needs grading.
Does reclaimed brick always save money?
No, and the mortar decides it. Brick laid in lime mortar can usually be cleaned and salvaged. Brick in modern cement mortar generally cannot, and ends up as hardcore. Add double handling, site storage, protection and breakage, and the saving disappears unless the material has high value or high disposal cost.
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.