Missing building regs: indemnity insurance or regularisation?

Two consents, two certificates

Building work on a house can need two separate things. Planning permission decides whether you may build something at all, and what it looks like and is used for. Building regulations approval governs how it is built: structure, fire safety, insulation, ventilation, drainage. GOV.UK warns that without building regulations approval “you will not have the certificates of compliance you may need when you want to sell your home”, which is exactly where buyers meet the problem.

The two are easy to confuse. Many single-storey extensions are permitted development and never need a planning application, yet still need building regulations approval. A seller who says “we did not need permission” may be right about planning and still have no completion certificate. For work done under a competent person scheme (replacement windows, a new boiler, rewiring), the installer's scheme certificate is the evidence instead, so ask for those too.

The enforcement clocks are longer than they were

A missing certificate matters because the council can act on non-compliant work. Under section 36 of the Building Act 1984, a notice requiring offending work to be removed or altered could once be served only within 12 months of completion. In England, since 1 October 2023, the limit is 10 years from completion; Wales followed on 1 July 2026. Transitional rules govern older work, so the limit that applies to a particular extension is a question for your conveyancer.

Planning enforcement changed too. For operational development substantially completed in England on or after 25 April 2024, a single 10-year limit applies; the old four-year rule still governs development completed before that date. The practical upshot for a buyer is simple: recent unapproved work carries a real enforcement risk for longer than the old rules of thumb suggest.

What an indemnity policy does, and does not do

A building regulations indemnity policy covers certain financial losses if the council takes enforcement action over the missing approval. It is cheap, quick and arranged by the conveyancer, which is why it is so common. But it is insurance against a council acting, not a statement about the building: nobody inspects the work, and a policy will not pay to put right a defect simply because it is a defect.

The condition that catches people out is the one about the council. Policies usually become void if anyone approaches the council about the work. That means you cannot ask building control whether they have records, and you cannot start a regularisation application, without losing the cover. Decide on the route first.

What regularisation involves

Regularisation is the formal route to retrospective approval. In England the application covers unauthorised work carried out on or after 11 November 1985 and includes a description of the work and plans of it and of anything needed to bring it up to standard. The council may require the work to be laid open for inspection, tested or sampled, and may require changes. If it is satisfied, it issues a regularisation certificate: evidence, though not conclusive evidence, that the requirements it names have been met.

That is more disruptive and slower than insurance, and the outcome is not guaranteed. It is also the only one of the two routes that tells you anything about the work. As a buyer the cleanest version is the seller regularising before exchange, at the seller's cost and risk.

Spotting the issue before you offer

Most buyers discover a missing certificate weeks into the conveyancing, after paying for a survey and searches. You can often see the warning signs earlier. Energy performance certificates record extensions, and comparing certificates over time against the last sale date can show whether work was done under the current owner, who should then hold the paperwork. The hand-checked section of a £24.99 Complete report covers registers that have no API; for an altered house that can include the council's planning and building-control records, where the council lets them be searched, and the report says so when it does not. Then ask the questions in writing before you offer, and see our guide to reports and surveys for what the surveyor should look at.