What is a Building Regulations completion certificate?

A completion certificate proves Building Regulations work was checked and approved; it's separate from planning permission.

BR-01The short answerA Building Regulations completion certificate is a document confirming that work has been inspected and meets the Building Regulations. It's issued by your council's Building Control team or a registered building control approver, not by the planning department. You need one for most notifiable building work, such as extensions, loft conversions, and some electrical or gas jobs.

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Under the Building Act 1984, certain building work must be checked and signed off by Building Control.

BR-02This guide covers England firstThis guide explains the system in England. Wales, Scotland and Northern Ireland have their own building control systems and different certificate names, covered in the last step.

BR-03What decides if you need oneWhether you need a completion certificate depends on the type of work, not a size or distance limit. Structural changes, new extensions, electrical rewiring, and gas installations are usually notifiable. Minor cosmetic work, like replacing tiles or painting, is not. If you're not sure your project counts, ask your local Building Control team or check the Planning Portal before you start.

BR-04Exceptions that change thingsFlats and maisonettes often have extra rules because shared structures are involved. Listed buildings and conservation areas may need separate consent alongside Building Regulations approval. If a job was done under a competent person scheme, such as a Gas Safe registered engineer or an electrician registered with NICEIC, you'll get a compliance certificate instead of a council completion certificate, but it serves the same legal purpose.

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Work on listed buildings usually needs listed building consent as well as Building Regulations approval.

BR-05Planning permission and Building Regulations are differentA completion certificate only relates to Building Regulations, which cover safety and construction standards. It has nothing to do with planning permission, which covers what you're allowed to build. You can have planning permission but still fail to meet Building Regulations, or need Building Regulations approval for work that never needed planning permission at all.

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Planning permission and Building Regulations approval are legally separate processes and both may be required.

BR-06Who to ask and howContact your local council's Building Control service or a registered building control approver before work starts. For electrical or gas work, check if your installer is part of a competent person scheme, such as Gas Safe Register, so they can self-certify. The Planning Portal website explains the process and links to official contacts.

BR-07Costs and timescalesBuilding Control fees vary by council and project size, typically ranging from around £150 for small jobs to £1,000 or more for larger extensions. Inspections happen at key stages, and the final certificate is usually issued within a few weeks of the last inspection, once all checks pass. Get an exact quote from your council or approver before committing.

BR-08What happens if you skip itDoing notifiable work without Building Control sign-off is a breach of the Building Act 1984. The council can ask you to expose and redo the work to prove it's safe, even years later. When you sell, solicitors usually ask for completion certificates, and missing ones can delay or block a sale unless you get an indemnity insurance policy, which is a costly fallback, not a fix. If work was done without approval, you can apply to your council for a 'regularisation certificate'. They inspect the work, may ask you to open some of it up, and sign it off if it complies. It costs more than doing it properly at the time.

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KNOW THE RULES

Carrying out notifiable work without Building Control approval is an offence under the Building Act 1984.

BR-09If you live in Wales, Scotland or Northern IrelandWales follows a very similar system to England, also through the Planning Portal. In Scotland, you get a building warrant before starting, then submit a completion certificate when the work is finished, which the council accepts after checking it. Check mygov.scot. Northern Ireland has its own planning and building control system entirely separate from GB; check nidirect for guidance.

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