CPR Part 35 expert evidence in commercial lease dilapidations disputes — terminal schedules, quantified demands and section 18(1) diminution valuations.
Dilapidations disputes sit at the end of almost every commercial lease — and when a claim heads towards proceedings, both sides need evidence that survives the Dilapidations Protocol and CPR Part 35. Our RICS building surveyors and Registered Valuers act as dilapidations expert witnesses for landlords and tenants across England and Wales.
Dilapidations matters the panel's experts give evidence in
- Terminal dilapidations claims — preparing or rebutting schedules of dilapidations and quantified demands at lease end, item by item against the repairing covenant.
- Section 18(1) diminution valuations — the statutory cap that so often decides these cases: damages cannot exceed the reduction in the landlord's reversion, a valuation exercise our Registered Valuers run alongside the building surveying evidence (see our valuation expert witness team).
- Break clause condition disputes — whether compliance conditions attached to a break option were satisfied, where the price of getting it wrong is the lease continuing.
- Interim schedules and repair covenant disputes — mid-term claims, self-help notices and specific performance arguments.
- Supersession arguments — evidence on whether the landlord's actual or intended works make claimed repairs irrelevant.
Why dilapidations evidence needs two disciplines
A dilapidations claim is really two expert questions stacked together: a building surveying question (what disrepair exists and what it costs to remedy) and a valuation question (what that disrepair actually does to the value of the landlord's interest). Claims collapse when one expert strays into the other's territory. Our panel supplies both disciplines, each reporting within their competence and to full CPR Part 35 standard — the same structure the Dilapidations Protocol expects, with its endorsement that schedules and responses be honestly held professional opinions.
Instruction and fees
The panel acts for landlords, tenants and — as Single Joint Expert — for both. Typical reporting is 2–4 weeks from inspection; dilapidations expert reports generally run £5,000–£15,000 depending on the property and schedule size, with screening advice from £500 — fee context in the expert witness cost guide. For non-contentious condition records at lease start, see our commercial building surveys.
Frequently asked questions
What is a section 18 valuation?
Section 18(1) of the Landlord and Tenant Act 1927 caps a landlord's terminal dilapidations damages at the reduction in the value of their interest caused by the disrepair — which can be far less than the cost of the works, and nil where the landlord intends to redevelop. It is a Red Book valuation exercise carried out by a Registered Valuer, and it decides more dilapidations disputes than any schedule does.
Can a tenant challenge a schedule of dilapidations?
Yes — the Dilapidations Protocol expects a reasoned response within 56 days. Common grounds: items outside the repairing covenant, remedial costs overstated, works superseded by the landlord's own intentions for the building, and the section 18(1) cap. A building surveyor's item-by-item rebuttal, supported where needed by a diminution valuation, routinely reduces claims substantially.
When should I instruct a dilapidations expert?
Landlords: before lease expiry, so the schedule is served promptly and reflects genuine intentions for the building. Tenants: the moment a schedule or quantified demand arrives — or earlier, before exercising a conditional break clause, where non-compliance can mean the lease continues. Early expert involvement narrows the issues while settlement is still cheap.