Expert Witness Evidence in Construction Adjudication

A construction adjudication expert is a chartered surveyor (or engineer) who provides independent technical evidence in a statutory adjudication under the Housing Grants, Construction and Regeneration Act 1996. Adjudication is fast: an adjudicator must reach a decision within 28 days of the referral, so the expert's job is to give the adjudicator a clear, reasoned view on defects, valuation or delay within days rather than months. This guide explains when expert evidence is worth commissioning, how it differs from a CPR Part 35 court report, what the report should contain and what it costs.

What is construction adjudication and when does it apply?

Adjudication is a statutory dispute-resolution procedure for construction contracts in England, Wales and Scotland. Part II of the Housing Grants, Construction and Regeneration Act 1996, as amended by the Local Democracy, Economic Development and Construction Act 2009, gives either party to a qualifying construction contract the right to refer a dispute to an adjudicator "at any time". Where the contract does not contain compliant adjudication provisions, the Scheme for Construction Contracts (England and Wales) Regulations 1998 is implied instead.

The key features are speed and interim finality:

• An adjudicator is normally appointed within 7 days of the notice of adjudication.
• The decision is due within 28 days of the referral, extendable by up to 14 days with the referring party's consent, or longer if both parties agree.
• The decision is binding until the dispute is finally determined by litigation, arbitration or agreement, which is why adjudication is often described as "pay now, argue later".
• The Technology and Construction Court will usually enforce the decision by summary judgment.

One important exclusion for homeowners: under section 106 of the 1996 Act, contracts with a residential occupier for work on their own home fall outside the statutory right to adjudicate. Many standard-form homeowner contracts include a contractual adjudication clause, so check the contract terms first. Where adjudication is not available, a defects claim proceeds through the courts and the guide to expert witness evidence in building defects claims applies instead.

Why expert evidence matters in a 28-day timetable

Adjudicators are usually experienced construction professionals or lawyers, and the Act allows them to take the initiative in ascertaining the facts. Even so, an adjudicator cannot inspect every property or re-measure every account. A focused expert report does that work for them, and in a compressed timetable the party with the clearest technical case usually has the advantage.

The disputes in which the panel's construction experts are most often instructed include:

• Defective workmanship – whether work complies with the specification, the Building Regulations and relevant British Standards, and what remedial works are reasonably required.
• Valuation of the works – interim or final accounts, variations and omissions, including the cost of rectifying defects set off against sums claimed.
• Delay and extensions of time – whether delaying events were the contractor's or employer's responsibility and how they affected the completion date.
• Practical completion and termination – whether the works had reached the required stage, and the condition of the site at termination.

For a wider view of when technical evidence is needed on a defects dispute, see when to hire an expert witness for construction defects.

How does an adjudication expert differ from a CPR Part 35 expert witness?

Adjudication is not court litigation, so the Civil Procedure Rules, including CPR Part 35 and Practice Direction 35, do not formally apply. That has three practical consequences.

First, no permission is needed to rely on expert evidence, and there is no automatic exchange of reports, written questions or joint statements. Each party serves the evidence it relies on with its referral or response, and the adjudicator decides what weight to give it.

Second, the expert's professional obligations remain. RICS members who give expert evidence in any forum, including adjudication, are bound by the RICS practice statement and guidance note Surveyors acting as expert witnesses. The report must be the expert's own independent opinion, set out the facts and assumptions it relies on, and not be shaped by the instructing party. Adjudicators are quick to discount partisan reports.

Third, the expert may wear two hats. Before a referral a surveyor is often engaged as an expert advisor to assess the strength of the case, then produces an independent report once the adjudication starts. The line between those roles matters if the dispute later goes to court; the differences are explained in expert witness vs expert advisor.

Because the decision is only temporarily binding, an adjudication report is often the foundation for a fuller CPR Part 35 report if the losing party later litigates. It is sensible to prepare it to that standard from the outset.

What should a construction adjudication expert report contain?

There is no prescribed format, but a report that helps an adjudicator will normally include:

• Instructions and scope – who instructed the expert, the questions asked and any limits on the inspection or documents reviewed.
• Qualifications and independence – the expert's relevant experience and a statement that the opinions are their own, held independently of the instructing party.
• The contractual standard – the specification, drawings, Building Regulations and standards against which the work is judged, cross-referenced to the contract documents.
• Findings from inspection – dated photographs, measurements and test data, distinguishing what was observed from what is inferred.
• Analysis and opinion – whether each alleged defect is a breach, what caused it, and what remedial scheme is reasonable and proportionate.
• Quantum – costed remedial works or a valuation of the account, with the basis for each rate stated.
• A summary of conclusions – short enough to absorb on first reading, since the adjudicator may have only days to write the decision.

Where the complaint is a single defect, such as a leaking flat roof or cracking to a new extension, a targeted specific defect report can often be upgraded into adjudication evidence. Where the property's condition before the works started is in dispute, an existing schedule of condition is frequently the single most valuable document.

Timescales, fees and who pays

The timetable drives everything. A responding party typically has 7 to 14 days from the referral to serve its response, so the expert must inspect, review the documents and report within that window. Instructing the expert before the notice of adjudication is served, or as soon as one is received, gives the best chance of a considered report.

Fees follow the same bands as other expert witness work. The panel's experts generally charge £150–£300 per hour, with most adjudication reports on a single residential or small commercial project falling in the £5,000–£15,000 range. Complex multi-defect or delay disputes on larger projects can reach £20,000–£50,000 or more. Most adjudications are decided on the papers, but where a meeting is convened attendance is usually charged at £1,000–£2,000 per day. The full breakdown is in the expert witness cost guide.

On costs, adjudication differs sharply from litigation. Under the 2009 amendments each party normally bears its own legal and expert costs whatever the outcome, and contract terms that try to allocate those costs in advance are generally ineffective. The adjudicator's own fees are usually apportioned in the decision, most often against the losing party. Expert fees should therefore be budgeted as an unrecoverable cost and weighed against the sums in dispute before referring.

Construction adjudication experts from Survey Merchant

Survey Merchant provides RICS chartered building surveyors and quantity surveyors with adjudication experience as construction expert witnesses across England, Wales and Scotland. The panel's experts are used to referral and response deadlines, prepare reports that hold up if the dispute proceeds to the Technology and Construction Court, and act for contractors, employers, subcontractors and their solicitors. Survey Merchant matches the discipline to the dispute, whether the issue is workmanship, valuation or delay, and quotes fixed fees wherever the scope allows.

Other expert witness services on the panel include dilapidations, housing disrepair, valuation and party wall evidence. To discuss an adjudication that is under way or expected, contact Survey Merchant or call 0204 579 8270.