The short answer
Where a re-roof is notifiable under Building Regulations, the building control body issues a completion certificate once it is satisfied with the finished work. Separately, the roofer should give you a written guarantee and the survey photographs. A smaller repair that needs no approval produces no certificate, but you should still keep the invoice and guarantee.
Which re-roofs need a certificate at all
Not every roofing job is notifiable. According to the Planning Portal, a repair or re-cover that affects under 25 per cent of the building envelope and under 50 per cent of the roof does not usually call for approval. Below that line, no application is made and no certificate is issued.
Above it, the picture changes. A full replacement usually exceeds the roof threshold, so the work is notifiable. The same applies if a new covering adds 15 per cent or more to the weight on the rafters, and a roof counted as a thermal element can be required to meet today's insulation standards.
Notifiable work goes either to B&NES Building Control or to a registered building control approver, the private route that replaced approved inspectors in April 2024. Either one will inspect the work at stages and sign it off. Which route is used depends on you, though we advise on both and handle the application where this applies.
If you are in doubt about whether your own job is notifiable, ask your building control body before work starts. Guessing wrongly can cause difficulty when you come to sell.
What the building control body issues
Once the roof is finished and the inspector has seen the key stages, the building control body issues a completion certificate. It confirms that, at the time of inspection, the work met the Building Regulations. Typical stages inspected on a re-roof are the strip-out, the timbers and the insulation before it is covered up, and the finished roof.
The certificate is a record of the regulations, not a guarantee of the workmanship. It does not promise the roof will stay watertight for any length of time. That is the job of the roofer's guarantee, which is a different document.
A registered building control approver has its own form of sign-off certificate. In practice the paperwork serves the same purpose for a buyer's solicitor: it shows the work was inspected and accepted. Ask for a copy as soon as it is available, and file it with the house deeds.
The Planning Portal publishes a guide to re-roofing and Building Regulations that sets out the same thresholds in plain language, and it is worth reading before you speak to anyone. Keep in mind that the certificate relates to the regulations only. It says nothing about colour, tile choice or whether the finished roof looks right from the street, so those points should be settled in the specification.
The roofer's guarantee and the rest of the file
A completion certificate is one document in a set. The others come from the roofer.
- The written guarantee. Ours is a workmanship guarantee that lasts ten years, in writing. It covers the labour and installation. It is not insurance-backed, and it sits beside whatever guarantee the material maker gives on the slates, tiles or membrane.
- The survey and progress photographs. These show the condition of the roof before and the build-up under the covering, which nobody can see once it is finished.
- The invoice and specification. It should list the covering, underlay, fixings and lead used, details a future owner will want.
- Any consent. If the house is listed, a copy of the listed building consent from B&NES goes in the same folder.
Keep these papers together, on paper or as one digital file. We give you the guarantee and photographs when the job is finished.
Why it matters when you sell
A buyer's solicitor will ask about work done to the property, and a roof is one of the first items. If the roof was replaced and the work was notifiable, they will look for the completion certificate. A missing certificate does not stop a sale, but it raises questions, and it may mean going back to building control after the event, which is slower and dearer than dealing with it at the time. Solicitors tend to raise this early, and an open enquiry can hold up an exchange of contracts.
Lenders and surveyors read the roof too. A recent re-roof with paperwork gives them something concrete. Our page on whether a new roof adds value looks at what a survey does and does not take into account.
It also helps for the long term. If a leak shows up five years on, the photographs and specification show what was built, which makes the repair quicker and any conversation about responsibility shorter. For the next owner, the record is worth more than the roof's novelty.
Preparing for the paperwork
Much of the paperwork is easier if it is planned at the start. Before a loft is cleared and covered, the inspector may need to see the timbers and any insulation, and a clear loft makes that visit simple, as preparing the loft before a roof is replaced explains. On a terrace, the junctions with neighbours are inspected too; see the page on re-roofing a terraced house.
Price is the other piece. The cost of the application and any inspection fees are part of the quotation, not an extra at the end. Roof replacement cost gives typical UK ranges and the cost drivers behind them.
When your quote arrives, check that it says who applies to building control and who pays. Our own written price names the covering and the regulations step clearly. For the wider process, see roof replacement.
