Demolition’s real commercial fight: who pays when the survey misses something?

What happened

Adrian Corrigan, president of the National Federation of Demolition Contractors, has argued that demolition specialists are too often appointed after the design, programme and procurement strategy have already been fixed.

His point is that this shuts out the people most likely to identify the conditions that can stop an enabling-works package: hidden structural alterations, asbestos and other hazardous materials, contamination, restricted access, temporary-works requirements and an unworkable demolition sequence.

Corrigan says risk management should begin during project planning, not when demolition starts. Early surveys and specialist input will not remove every unknown, but they can expose more of them before the price and programme are committed.

The scale of the sector makes that important. Defra reports that England generated 63 million tonnes of non-hazardous construction and demolition waste in 2022, of which 94.3% was recovered. Separately, HSE provisionally recorded 25 construction worker fatalities in Great Britain during 2025/26—the highest number among the main industry sectors, although not the highest fatal-injury rate.

The commercial issue is what happens when the information provided at tender is incomplete, qualified or wrong. Was the condition included in the subcontractor’s risk, or is it a change to the priced scope? That question needs answering before the first wall comes down.

Does this affect you?

This is an opinion piece, not a new rule, regulation or contract award. It does not change your current subcontract by itself.

It matters if you undertake demolition, soft strip, asbestos removal, temporary works, structural alterations, remediation or groundworks on refurbishment and redevelopment sites. It also matters to anyone preparing the tender information or deciding where existing-condition risk sits.

If you work only on new-build greenfield sites, the direct relevance is limited—although the wider lesson about incomplete site information still applies.

Subby Mate: if you are on the tools

The one thing: Before disturbing the fabric of an existing building, ask: “Have we got the refurbishment and demolition asbestos survey covering this exact area and this work—and what parts could not be inspected?” If the information is missing or does not cover the work, do not disturb the affected area until the site team has resolved it.

• A management survey is not automatically enough for intrusive strip-out or demolition. Check that the survey is the correct type, covers the exact rooms and work areas, and identifies any exclusions or inaccessible locations. A drawing title or a WhatsApp message saying “survey done” is not a substitute for reading the relevant information.
• If you uncover suspected asbestos, an unexpected structural alteration, an unsupported element or another unsafe condition, stop disturbing the area and tell the site manager. Photograph and measure it only where it is safe and site rules permit. Record the location, time and drawing you were working from, then ask for written direction before continuing.
• A message asking for information does not automatically make the resulting delay payable. It does, however, show that you raised the missing information before starting. Follow the project communication route and any notice requirements rather than relying on a private note or an unanswered message.
• If you are asked to price from a walk-round with no intrusive survey or reliable structural information, qualify the price in writing. Identify exactly what information you used and what has been excluded. Do not promise a fixed price for conditions nobody has been able to inspect.

If you are a subcontractor QS

• List the survey information forming the basis of your tender by title, reference, revision and date. Record inaccessible areas and stated limitations. A general qualification such as “subject to survey” is weaker than a clear schedule showing what you relied upon.
• Define how unidentified conditions will be dealt with. A suitable tender qualification might state: “Our price excludes the removal, treatment or disposal of asbestos-containing materials not identified in the refurbishment and demolition survey [reference], together with structural conditions not shown in the listed tender information. Any such discovery may require adjustment to price and programme, subject to the subcontract terms and written instruction.”
• Do not confuse the asbestos survey, structural investigation and pre-demolition resource audit. Each answers a different question. If quantities, sequencing, temporary works or waste targets depend on information that has not been provided, state the assumption and its effect on your price and programme.
• Treat the 94.3% recovery figure carefully. It is an England-wide rate for non-hazardous construction and demolition waste, not a guaranteed outcome for an individual building. If the contract contains a recovery or diversion target, agree the measurement method, denominator, exclusions and treatment of hazardous or contaminated material. Base the target on a project-specific material audit rather than a national headline.
• If you are brought in early, agree the scope and status of your input. Buildability advice, surveys, demolition sequencing, temporary-works design and design calculations carry different responsibilities. State the deliverables, fee, reliance position and professional indemnity requirements before attending repeated workshops or producing information that others will use.
• When an unexpected condition appears, follow the subcontract rather than assuming it is automatically a variation. Give the required notice, identify the affected activity, record labour and plant, and explain the effect on sequence and programme. The survey request helps your evidence; the contract determines entitlement.

If you are a main contractor QS

• Decide the existing-condition risk allocation before issuing the enabling-works tender. State which surveys the client or main contractor will provide, which investigations the demolition contractor must undertake and how an unexpected condition will affect price and time. If the subcontractor is expected to price the risk, give it enough information and access to do so.
• Issue the correct asbestos information. For demolition or intrusive refurbishment work, identify the refurbishment and demolition survey covering the work area, together with its plans, sampling information, exclusions and inaccessible areas. Statutory health and safety duties are not removed by a broad subcontract disclaimer.
• Make the contractual status of third-party surveys clear. Identify who commissioned each report, whether reliance is permitted, its limitations and whether the contractor must verify anything. This is not about disclaiming every report; it is about preventing the same document from being treated as reliable for pricing but “information only” when a problem appears.
• Bring the demolition specialist in early where its knowledge can materially change the sequence, temporary works, logistics or waste strategy. If early involvement is advisory, define the deliverables and responsibility. If it includes design, appoint and insure it accordingly. Early engagement should reduce uncertainty, not create free and undefined design liability.
• Treat requests concerning stability, temporary works, hazardous materials, exclusion zones or sequencing as safety matters first. Record the decision, the responsible designer or temporary-works function, and any programme consequence. Commercial discussions must not delay action needed to make the work safe.
• Set project waste targets from the material audit and agreed scope. Define how reused, recycled, recovered, hazardous and contaminated materials will be recorded so the target is measurable and does not change meaning during the job.

Risks and what to do about them

• The asbestos survey does not cover the work area: Check the survey type, scope, plans and exclusions before disturbing the fabric. Raise a formal hold point or request for information where coverage is missing.
• The building differs from the structural information: Identify the tender baseline, record the discovery safely and obtain written direction. Follow the notice provisions and demonstrate the effect on method, temporary works, labour, plant and programme.
• A survey is relied upon at tender but disowned after discovery: State in the tender documents what each report is for, whether reliance is permitted and what verification remains with the contractor.
• A national recovery rate becomes a fixed project guarantee: Replace the headline percentage with a target based on the project material audit, supported by defined measurement rules and exclusions.
• Early specialist advice becomes unpaid design responsibility: Agree the scope, deliverables, fee, reliance and insurance position before the advice is produced.
• A safety concern is treated only as a variation negotiation: Make the area safe first, record the issue and then deal with time and money through the contract.

Do this week

Ten minutes: On your next demolition or refurbishment package, ask for the refurbishment and demolition asbestos survey covering the exact area and work scope. Check its reference, revision, plans and inaccessible areas. If it is missing or inadequate, raise a formal request or hold point and do not disturb the affected fabric.

A day, if you can spare it: Review your last three demolition or strip-out tenders. Record which asbestos, structural, contamination and material-recovery information was provided; which areas were excluded; what you assumed; and whether those assumptions appeared in the tender. Use the results to create a standard existing-conditions schedule for future bids, with spaces for document references, limitations, risk allocation and the mechanism for changing price and programme.

Source: Adapted from publicly available construction industry news, analysed by QS-AI.