No Building Regulations Sign-Off: Indemnity Policy or Regularisation?

"The vendor should be asked to provide evidence of building regulations approval for the alterations." It is a quiet sentence, it usually turns up alongside something the listing was proud of — the loft room, the open-plan kitchen, the conservatory — and it is one of the few survey findings that is genuinely a problem more often than not.

Not because the work is necessarily dangerous. Usually it isn't. But because it is the one finding where the cost is unpredictable, the seller frequently cannot fix it, and the solution most likely to be offered to you is the one that helps you least.

Here is what happens when the paperwork does not exist, what the three routes actually cost, and how to tell the version you can live with from the version you cannot.

Planning permission and building regulations are not the same thing

Buyers and estate agents use these interchangeably and they are completely different regimes.

Planning permission is about whether you were allowed to build the thing — its size, its appearance, its effect on the neighbours. It is enforced by the council's planning department and it is time-limited, but the limit changed recently and a lot of advice online is out of date. In England, since 25 April 2024, all breaches of planning control are subject to a ten-year limit. The old four-year rule for building work still applies to development substantially completed before that date, under transitional arrangements — so for most alterations you will encounter on an older house, four years remains the relevant figure. In Wales the four-year rule is unchanged.

Building regulations are about whether the thing is safe and properly built — structure, fire escape, insulation, ventilation, electrics, drainage. Enforced by building control. Prosecution is time-limited, but the obligation to make the work compliant is not, and a local authority can serve an enforcement notice requiring alteration or removal of non-compliant work with no equivalent deadline.

So a conservatory that has been up for fifteen years is almost certainly safe from planning enforcement, and that tells you nothing at all about whether the electrics in it are legal. Anything built since April 2024 is a different matter and stays exposed for a decade — worth checking on a recent extension.

The paperwork you are looking for is a completion certificate from building control, or a final certificate from an approved inspector. Not an application, not a plans-approval letter, not a receipt. Approval to start is not evidence that anybody came back to check the finished work — and a job that was started under approval and never signed off is one of the commonest ways this happens.

What tends to be missing, and what it actually matters for

Loft conversions are the big one, and the most consequential. The requirements are specific and mostly about fire: a protected escape route down the stairs, fire doors to habitable rooms off that route, mains-linked interlinked smoke alarms, an escape window of the right size and position, and structural calculations for the new floor and any altered rafters. A "loft room" without these is not a bedroom, whatever the listing says, and your surveyor will describe it as a room rather than a bedroom for exactly that reason.

Removed load-bearing walls — the open-plan kitchen-diner. The question is whether there is a properly sized steel or lintel with adequate bearing, designed by somebody who calculated the load. Sometimes there is and nobody kept the paperwork. Sometimes there isn't.

Electrical work — since 2005 most fixed electrical work in a home has been notifiable. In practice this means either a competent-person scheme certificate from the electrician or a building control sign-off. Consumer unit replacements and new circuits are the usual gaps.

Extensions and garage conversions — foundations, damp-proofing, insulation, ventilation. Rarely dangerous, frequently unprovable.

Replacement windows — since 2002, FENSA or equivalent certification. Very common gap, and the least serious of the lot.

Boiler installations and bathrooms in new locations — Gas Safe notification, and drainage and ventilation for the bathroom.

Route one: an indemnity policy

This is what the seller's solicitor will offer, often within a day of your solicitor raising it, and often at the seller's expense. It costs £20 to £300 as a one-off premium and lasts forever.

Understand what it does. An indemnity policy insures you against the local authority taking enforcement action. That is all. It does not:

• Make the work compliant
• Make the work safe
• Pay to put anything right if it turns out to be badly built
• Help you at all if the problem surfaces because something failed rather than because the council knocked

And it has a fatal practical feature: the policy is usually voided if anybody approaches the council about the work. So the moment you accept one, you have given up the ability to ask building control whether a record exists, and you cannot apply for regularisation later without invalidating it.

An indemnity policy is a reasonable answer for old, minor, low-risk work where the only realistic exposure is a remote enforcement risk — a 1990s conservatory, replacement windows from 2004. It is a poor answer for a loft conversion or a removed structural wall, because there the risk you care about is not enforcement. It is that the thing is not safe, and an insurance policy against a council letter does nothing about that.

Sellers and agents like indemnity policies because they are quick and cheap and make the enquiry go away. That is precisely why you should be sceptical when one is offered for something structural.

Route two: regularisation

A regularisation certificate is a retrospective application to building control for unauthorised work carried out after 11 November 1985. You apply, they inspect, they tell you what needs doing to bring it up to standard, you do it, and they issue a certificate.

This is the route that actually solves the problem, and the only one that leaves you with a document to hand the next buyer.

Costs, in two parts:

• The council's regularisation fee — usually somewhere around £300 to £900 for domestic work, varying by authority and the scale of what is being regularised. Councils typically charge a premium over the equivalent standard application.
• The remedial work they require — the real number, and the unpredictable one.

For a typical loft conversion missing its paperwork, the remedial list is fairly predictable: a fire door at the top and bottom of the stair, mains-linked interlinked alarms, an escape window to current spec, and a structural engineer's calculations confirming the existing floor and trimmers. £3,000 to £8,000 all in is a realistic range, and it is the range we see most often. On a well-built conversion that just never got signed off, it can be far less.

The catch is that regularisation can require opening up — building control cannot certify what they cannot see, so they may want a section of ceiling or floor removed to inspect the structure, then made good afterwards. That is where an otherwise contained job gets more expensive, and it is the main reason the range is as wide as it is.

The overall range on the survey repair cost calculator for alterations with no sign-off is £800 to £6,000, and a loft room with no completion certificate is listed separately at £2,000 to £12,000 — the higher figure reflecting that a loft is the case most likely to need real structural work rather than a fire door and some alarms.

Route three: get the seller to sort it before completion

Rarely offered, always worth asking for, and the strongest outcome if you can get it. The seller applies for regularisation, does the work, and hands you the certificate at completion.

It is a hard ask on a chain with momentum, because it takes weeks. But it is a very reasonable one where the alternative is that you take on an unquantified structural risk, and it costs nothing to raise. A seller facing the choice between doing it and losing the buyer will sometimes do it — and if they refuse, that tells you something too.

How to work out which situation you are in

Before you decide anything, establish three things.

When was the work done? Post-1985 work can be regularised. Pre-1985 work cannot — regularisation does not apply — which sounds worse and usually is not, because anything that old has proved itself over decades. Ask the seller, and ask the neighbours, who often remember.

Can building control confirm anything? A quick check of the council's records may turn up an application nobody could find. Do this before accepting an indemnity policy, because you cannot do it afterwards.

Is it actually built properly? This is the question that matters most and the one nobody asks. A loft conversion done well by a competent builder who simply never called building control back is a very different proposition from one done badly at a weekend. Somebody who knows what they are looking at can tell you a great deal in half an hour: whether the floor joists are the right depth, whether the stair is compliant, whether there is a steel over the opening and how it is bearing, whether the escape window is the right size.

That last question is where the money is. It is the difference between a £3,000 fix and a £12,000 one, and no document will answer it for you.

What to do about it in the negotiation

This is a strong finding to raise, for a reason that is worth stating plainly: it is a defect the seller can be assumed to know about, unlike a perished roof underfelt or a blocked drain. Somebody in that house commissioned the work, and either it was signed off or it was not.

Ask for the cost of regularisation and the likely remedial work, quantified. If the work is a loft conversion being marketed as a bedroom, there is a second argument — the property has been presented as having more habitable rooms than it can be certified to have, which speaks to the price rather than just the repair bill.

Our guide to how much you can negotiate off after a survey covers how to put a schedule together, and what "further investigation is recommended" costs covers the structural engineer's report you may want first.

When to walk

Most of these are solvable. A few are not:

• A removed load-bearing wall with no visible support and no calculations. Until somebody has established what is holding the floor above up, nothing else is worth discussing.
• A loft conversion with no realistic escape route. If the stair arrangement cannot be made compliant without rebuilding it, the room can never be a bedroom, and you are paying for a house with fewer rooms than advertised.
• A seller who will not permit any investigation. Reluctance to let a structural engineer look at unauthorised structural work is information in itself.
• Work that would need substantial demolition to regularise. Rare, but it happens, and the cost is open-ended.

The short version

An indemnity policy insures you against a council letter and nothing else, voids itself if you contact the council, and is the wrong answer for anything structural. Regularisation costs a few hundred in fees plus whatever the work needs — typically £3,000 to £8,000 on a loft — and is the only route that leaves you with a certificate. Before you choose, find out when the work was done, check the council's records while you still can, and get somebody to tell you whether the thing is actually built properly, because that is what determines the number.

If your survey has flagged alterations with no sign-off and you want a builder's read on how well the work was actually done before you decide between an indemnity policy and regularisation, send us the report and the photos — £59, back within 24 hours. One question on its own is free.