Building Safety Act 2022 and surveyor PII: the extended limitation window

~5 min read

Reviewed by Matthew Bartlett, Director · Last reviewed 2026-07-06

Section 135 of the Building Safety Act 2022 amended section 1 of the Defective Premises Act 1972 to extend the limitation period for claims relating to defective residential dwellings — retrospectively to 30 years and prospectively to 15 years. That single legislative change has reshaped the professional indemnity landscape for any surveying discipline touching residential building work: building surveyors, party wall surveyors, structural engineers acting as expert surveyors, dilapidations surveyors on residential property, and Red Book valuers whose valuation was relied on in a lending decision on residential dwellings. The retrospective element means historical files that everyone had assumed were closed under the previous six-year limitation are now potentially live. This entry sets out what changed, what it means for PII placement, and how firms and brokers are handling the exposure.

What section 135 did

Before the BSA, section 1 of the Defective Premises Act 1972 imposed a duty on those taking on work in connection with the provision of dwellings — to see that the work is done in a workmanlike or professional manner. That duty was subject to a six-year limitation under the Limitation Act 1980. Section 135 of the BSA 2022 changed the limitation period. For defective residential dwellings that were completed before the BSA commenced (28 June 2022), the limitation period is now 30 years — a retrospective extension that pulled decades of previously time-barred files back into potential claim territory. For dwellings completed after the BSA commenced, the limitation period is 15 years — a prospective extension that increases the tail for all new work.

Which surveyors are exposed

The exposure attaches to any surveyor whose work fell within the scope of section 1 of the DPA 1972 — the "provision of dwellings" test. That captures building surveyors who provided professional services in connection with the construction, conversion, alteration or repair of a dwelling; Red Book valuers whose valuation was used in a lending or investment decision on a dwelling; party wall surveyors whose awards or advice touched on dwelling construction; and expert witness surveyors in disputes concerning dwelling defects. It does not attach to surveying work on commercial property unless that work also touched residential elements of a mixed-use scheme.

The retrospective element

The retrospective 30-year limitation is the more difficult of the two changes to price. A file that a surveyor closed in 2005, believing the six-year limitation had run in 2011, is now potentially live until 2035 (30 years from the DPA-relevant date, subject to specific fact-based analysis). Firms that had assumed their historical residential work was risk-cleared by the passage of time have had to reassess. In practice, insurers have responded by asking more searching proposal-form questions about historical residential work, tightening aggregation wordings, and — for firms with material historical residential exposure — either declining renewal or pricing accordingly.

The prospective element

The 15-year prospective limitation is easier to price because it operates going forward from a defined date. Insurers underwriting surveying work on residential dwellings now factor a 15-year claim tail into pricing rather than the six-year tail that applied before the BSA. That is a material change to the underwriting mathematics but not a retrospective shock.

Run-off implications

The BSA 2022 change alters the run-off calculus materially. The RICS PII Requirements mandate a six-year run-off floor on cessation. For a firm with material residential exposure, six years is now demonstrably inadequate — a file completed in 2020 that becomes the subject of a claim in 2032 sits well outside a six-year run-off period. Brokers are increasingly recommending extended run-off of 15, 20 or even 30 years for firms winding down with residential back-books, particularly party-wall and dilapidations surveyors whose files may have touched dwelling defects long enough ago that the retrospective limitation captures them.

The extended run-off cost is not trivial. A five-year run-off multiplier looks materially different from a 15-year multiplier, and insurers are pricing the longer periods to reflect the retrospective limitation exposure. Firms considering cessation should engage a broker 12 months ahead of the intended cessation date so the cost of an extended run-off is known before the decision to cease is made — the run-off premium can be a decision-driver in the choice between cessation and succession.

Risk-selection changes

Some insurers have narrowed their appetite for residential-heavy surveying books since the BSA. That has produced a two-tier market: firms with modest or well-documented residential exposure can still find competitive terms; firms with heavy residential dilapidations or party wall books, or with unclear historical file records, face a smaller pool of willing insurers and higher rates. Firms in the latter category should engage a broker early at renewal — three or four months ahead — to allow time for a proper market approach.

Documentation matters

The retrospective element has raised the value of good historical file records. A firm that can produce a clear file for a 2015 residential building survey — the instruction, the report, the caveats, the client's confirmation of receipt — is materially better placed if a claim surfaces in 2028 than a firm relying on partial notes. Insurers reviewing proposal forms increasingly ask whether the firm's historical residential file records are accessible and reviewable, and the answer influences the underwriting outcome. Firms that have digitised historical files, or that maintain a robust document retention policy going back to the retrospective window, are in a better position at renewal.

Worked example

Illustrative only. A four-partner building surveying practice with material historical involvement in residential dwelling projects (dilapidations schedules, party wall matters, structural inspections) between 2005 and 2022. The practice intends to cease trading on 31 December 2027. Given the retrospective DPA extension, the historical back-book carries a claim tail that potentially runs to 2052. Broker recommendation: 15-year run-off rather than the six-year RICS floor, with a costed option to extend to 20 years. Total run-off premium substantially higher than a six-year placement but proportionate to the residential exposure carried forward. Documentation review carried out ahead of cessation so historical files are accessible for the run-off period.