Usually nothing at all — right up until you try to sell. Then the buyer's solicitor asks for a certificate that does not exist, and a sale that was weeks from completion stops dead. There are two ways out of it, and choosing the wrong one first closes the other permanently.
↓ What the certificate is, and why you have been asked for it 📋 Talk to Mike about regularisationThe buyer's solicitor has asked for building regulations paperwork for the loft, the extension or the knocked-through wall, and there isn't any. The sale is on hold and everybody is waiting on you.
You bought the house this way, or a builder assured you it was "all fine", and you have realised there is no certificate. Nothing is on fire — but you would rather deal with it now than under time pressure with a buyer waiting.
Both are fixable. The first is more expensive to fix badly, because a stalled sale gives you no time to think.
Conveyancers ask for a completion certificate on any extension, loft conversion or structural alteration as a matter of routine. No certificate is a raised enquiry, and enquiries take weeks to resolve at exactly the point when everyone wants to exchange.
A buyer's mortgage lender may decline, lend less, or hold a retention until it is resolved. You are then negotiating with someone who knows you cannot easily walk away.
If defective work later causes damage, a buildings insurer can refuse the claim.
The commonest serious failure in an unapproved loft is the escape route: no protected stairway, no fire doors, no compliant means of getting out. This is the part that matters more than the paperwork.
A lot of people have been told that if a council has not acted within twelve months, the work is effectively safe from enforcement. That was true. It is not any more.
Section 39 of the Building Safety Act 2022 extended the period for a council to serve an enforcement notice — requiring work to be altered or pulled out — from twelve months to ten years from completion. The same Act made contravening the building regulations an offence carrying an unlimited fine and up to two years' imprisonment.
It took effect in England during 2023. In Wales the commencement completed on 1 July 2026 — two months ago. So if the advice you were given predates that, it was reasonable at the time and is wrong now.
This is not the same thing as saying a council will come after you. Most do not go looking. It matters because the old advice made "do nothing" feel safe, and it no longer is — and because a buyer's solicitor will know.
Building regulations are the safety standards any extension, loft conversion, garage conversion or structural alteration has to meet — structure, fire escape, insulation, drainage, ventilation. They are a separate thing from planning permission, which only decides whether you may build at all. You can hold full planning permission and still have no building regulations sign-off, and plenty of people do.
When the work is notified properly, building control inspects it at stages and issues a completion certificate at the end. That is the document your solicitor is asking for. If nobody ever told building control the work was happening, no inspections took place and no certificate exists — however well the work was actually built.
The way to get the paperwork now is a Regularisation Certificate. It is a retrospective application: building control inspects what was built, which can mean opening up finished work, and issues the certificate once it complies or has been brought up to compliance. Only work that commenced after 11 November 1985 can be regularised.
It is the same standard applied late. Done properly it resolves the problem permanently — the work is signed off, the house is genuinely compliant, and the paperwork satisfies every future buyer, not just this one.
Almost nobody goes looking for this. It surfaces because somebody else asks for it, and it is nearly always one of these:
| Who is asking | Why they are asking |
|---|---|
| Your buyer's solicitor | A standard conveyancing enquiry on any extension, loft or structural alteration. Without the certificate they cannot confirm the work was lawfully done, so they will not let the sale proceed. |
| Your buyer's mortgage lender | The lender is securing a large sum against the house. Uncertified structural work is a risk on their book, and they can decline, lend less, or hold a retention. |
| Your own lender, on a remortgage | The same question asked of you rather than of a buyer. It stops equity release and product transfers just as effectively. |
| Your buildings insurer, after a claim | A claim connected to defective, uncertified work can be refused. This one usually surfaces at the worst possible moment. |
| The council | Enforcement. They now have ten years from completion rather than twelve months — see below. |
None of them are accusing you of anything, and most of the time the work was done by a builder who simply never notified anyone. They need a document. There is one way to get it, and it starts with somebody looking properly at what was built — which cannot be done from a description over the phone.
Regularisation is not a drawing job with a form attached. Most of the value is in knowing what the building control officer will want to see, and in the conversation with them on site.
He surveys what was built, not what was meant to be built. Joist sizes, the staircase, the escape route, insulation, where the structure actually bears. Some of this can be established without opening anything up; some cannot, and he will tell you which.
Before you commit. If what was built cannot realistically be brought to compliance without pulling it apart, that changes the decision entirely — and you are better off knowing it at the start.
Drawings of the existing work, the regularisation statements, and the evidence the council needs to judge compliance on work they never saw being built.
This is the part that decides it. Mike meets the building control officer at the property, walks them through the work, and agrees what needs to change.
Whatever the officer requires — a fire door, a handrail, an upgrade to the escape route — Mike specifies it and coordinates with your builder until it satisfies them.
He stays on it until the council issues the Regularisation Certificate, which is the document your buyer's solicitor is asking for.
“Mike Williams was extremely helpful in understanding what was required and very efficient in getting drawings completed and planning processed. I would not hesitate in recommending him to prospective customers.”
This is not the same job as drawing a new extension, so it is not priced the same way. It is a fixed consultancy fee for getting unauthorised work signed off.
By project. Where it lands depends on the size of the work, how much is hidden behind finished surfaces, and how much coordination the officer needs. Mike confirms the figure in writing after the Initial Site Appraisal Meeting, before anything starts.
Two costs sit outside this and are paid directly, never through Mike: your council's regularisation charge, which they set and which is normally higher than a standard building control charge; and any remedial building work the officer requires — which is real building work, priced by your builder.
Mike cannot guarantee a council will issue a certificate — nobody honestly can, because it depends on what was built. What he will do is tell you at the Initial Site Appraisal Meeting whether he thinks it is achievable, before you commit to the fee.
Every planning application Deeside Architectural Design submits goes onto the council's public register — under the practice name, with the decision attached, permanently. It's free to search and it isn't curated by us. What the register cannot show you is the other half of the work: the projects that qualified as Permitted Development, needed no application at all, and saved the client the council fee. Those leave no public trace. So the number below is the part you can check — not the whole of it. Before you decide whether the fee above is worth paying, go and read it.
Submitted to Flintshire County Council under Deeside Architectural Design since 2010 — every one searchable, with its decision attached.
Many projects qualify as Permitted Development, need no application, and never reach the register. The 165 is the work that required permission — not the count of jobs done.
Deeside Architectural Design Limited, incorporated January 2010, and 25 years of drawings behind it. Companies House no. 07128221.
Open Flintshire's planning register, put Deeside Architectural in the Agent field, and read every decision — including the ones that didn't go our way.
Search Flintshire's planning register →
Figures taken from Flintshire County Council's public planning register, August 2026.
He needs four things before he can tell you whether regularisation is realistic and what it will cost. It takes a minute, and there is no obligation at the end of it.
You can, but it usually complicates things. The buyer's solicitor asks for it as a matter of routine on any extension, loft conversion or structural alteration. No certificate means a raised enquiry, and possibly a lender declining, lending less, or holding a retention. Sales commonly stall at this point, often weeks in.
No. Telling building control about work that was never notified is the start of putting it right, not a mistake. What matters from here is that the application is prepared properly and that somebody who knows what the officer will look for is handling it.
Yes. Section 39 of the Building Safety Act 2022 extended the enforcement notice period from twelve months to ten years from completion, and made a breach an offence carrying an unlimited fine and up to two years' imprisonment. England from 2023; Wales completed commencement on 1 July 2026. The old twelve-month reassurance is out of date.
Only work that commenced after 11 November 1985 can be regularised. Anything earlier predates the route, and the conversation with your solicitor is a different one.
Mike's consultancy fee is £997 to £1,500 depending on size and complexity, fixed and confirmed in writing after the Initial Site Appraisal Meeting. Separately you pay the council's regularisation charge, which they set, and the cost of any remedial work the officer requires.
No, and be wary of anyone who says they can — it depends on what was actually built. What he will do is tell you honestly at the Initial Site Appraisal Meeting whether he believes it is achievable, before you commit to the fee.
Mike will tell you at the Initial Site Appraisal Meeting whether regularisation is achievable — before you commit to anything.
📋 Tell Mike what was built 📞 07703 786 460