Buying a house with no building regulations: what it means

Finding out that a house you are buying has an extension, loft conversion or knocked-through wall with no building regulations certificate is one of the most common hold-ups in conveyancing, and one of the most misunderstood. It rarely means the sale is doomed. But two things buyers are often told, that the work is “too old to matter” and that indemnity insurance “sorts it”, are not quite true, and the rules in Wales changed on 1 July 2026. Here is what missing building regulations actually means for the purchase, and what your options are.

What does “no building regulations” actually mean?

Building regulations are the standards that construction work has to meet, covering structural safety, fire safety, insulation, drainage and ventilation. When work is done properly, building control inspects it and, once satisfied, issues a completion certificate confirming it meets the standards. The document that usually turns out to be missing is that completion certificate: the final sign-off at the end of the job.

Often the work was approved at the outset but never formally signed off at the end, the final inspection simply never happened, something the pandemic made far more common. So “no building regulations” usually does not mean the work was never looked at; it means there is no certificate proving the finished work was inspected and passed. GOV.UK explains the basics of building regulations approval.

Building regulations vs planning permission: what’s the difference?

This is the single biggest source of confusion, so it is worth being clear. Planning permission and building regulations are two completely separate approvals, from different departments, doing different jobs.

Planning permission is about whether you are allowed to build something at all, its size, its appearance, and its effect on neighbours and the area. Building regulations are about whether what is built is safe and sound, structurally, and for fire, insulation and the rest. A property can easily have one without the other. So when a seller says “it has planning permission”, that tells you nothing about whether the building regulations were met. You can need both, and the two are checked and enforced separately.

Is it really a problem if the work is old?

The reassurance you will often hear is that the work was done years ago, so the council can no longer do anything about it. That used to have a kernel of truth, but it is now largely out of date.

Historically, under section 36 of the Building Act 1984, the council had only 12 months from completion to require unauthorised work to be altered or removed. That 12-month window is where the “too old to matter” belief comes from. It has now changed. In England, the Building Safety Act 2022 extended the enforcement period to up to 10 years, with effect from October 2023. In Wales, equivalent provisions came into force on 1 July 2026, so the old 12-month limit no longer applies here either, and the council’s enforcement window is now much longer.

There has also never been a time limit where work is dangerous: the authority can apply to the court for an injunction to deal with unsafe work at any time, however old it is. And in truth the enforcement window was always something of a red herring. The practical problems, a lender refusing to lend, a buildings insurance claim being turned down, or the work simply being unsafe, do not depend on whether the council can still act, and the same questions will come up again when you sell. “It’s old” is rarely the reassurance it sounds like.

What indemnity insurance does, and doesn’t, do

Indemnity insurance is the quick, cheap fix that tends to get offered, and it is widely misunderstood. It is a one-off policy, typically £20 to £526, lasting indefinitely and passing to future owners, that pays out if the local authority takes enforcement action over the missing approval.

What it does not do is the important part. It does not certify that the work is safe or built to standard. It does not pay to put the work right. It does not help if your buildings insurer later refuses a claim because there is no completion certificate. And it becomes void the moment anyone, you, the seller, or a surveyor, approaches the council about the work. That last point matters, because it means you cannot hold an indemnity policy and apply for regularisation: contacting the council to check the work kills the policy.

Indemnity insurance is best understood as something that satisfies a mortgage lender’s paperwork, not something that makes the problem go away. If the work is genuinely substandard, a policy leaves you owning an unsafe building with a piece of paper that only covers the council’s enforcement costs.

Regularisation: the proper fix

The alternative is regularisation, applying to building control for retrospective approval. An inspector visits, assesses the work, and, if it meets the standards, issues a regularisation certificate. If it does not, they will specify what has to be put right first.

There is no time limit on applying, but regularisation is only available for work carried out after 11 November 1985, and in practice most councils will only consider it for work up to around 10 to 15 years old. It usually costs between £400 and £1,200. The catch is that the inspection can be intrusive, parts of the structure may have to be opened up so the work can be checked, and if it does not comply, you or the seller face the cost of putting it right. That risk is why sellers often resist it. But unlike indemnity insurance, regularisation actually confirms the work is sound, which is worth far more in the long run. Once you have approached the council this way, indemnity insurance is no longer an option, so it is a deliberate choice between the two, not both.

What are your options as a buyer?

When your solicitor’s enquiries reveal missing building regulations, there are a few routes, and the right one depends on the work and how comfortable you are with it. You can ask the seller to apply for regularisation before completion, the cleanest outcome, though it takes time and sellers often resist. You can instruct a structural engineer or surveyor to inspect the work, which gives you an independent view of whether it is sound without alerting the council, and a basis on which to negotiate. You can accept indemnity insurance, usually paid for by the seller, remembering what it does and does not cover. Or you can negotiate a reduction to reflect the cost and risk, and, occasionally, decide to walk away.

Bear in mind that the decision may not be entirely yours. Your solicitor also acts for your mortgage lender, and most lenders insist on either regularisation or indemnity insurance being in place before exchange. A missing certificate is often first flagged by the local authority search, and sorting it out is one of the things that can add time to a purchase, so it is worth raising early.

Will it cause problems when you sell?

It is worth thinking ahead, because whatever you accept now, you inherit the issue. If you buy with indemnity insurance, the policy passes to you, but the underlying lack of certification remains, and your own buyer’s solicitor will raise exactly the same enquiry. Plenty of houses with older, unsigned-off work sell perfectly well, provided the work is sound and either the paperwork or a policy is in place. The problems come when the work is actually defective, or when a buyer’s lender is stricter than yours was. Getting the work properly regularised, rather than papering over it, is what removes the issue for good.

How we help

Our conveyancing team deals with missing building regulations on purchases across South Wales and the South West all the time. We tell you plainly what the missing paperwork means for your purchase, what your lender is likely to accept, and whether indemnity insurance or regularisation is the right route for your situation, and we handle the negotiation with the seller’s solicitor. To get started, request a callback and we will come back to you.

A note on figures: the fees and figures in this article are correct as at the date of publication shown on this article. Court fees, taxes and other charges change from time to time, so please check the current figures with the relevant official source before relying on them.