Building regulations sign-off: completion certificates for extensions and loft conversions
KRAMAN Ltd. Published 29 October 2026. Rules checked on 29 October 2026 against the GOV.UK and Planning Portal guidance listed under Sources below.
Building regulations approval is separate from planning permission. Converting a loft into a liveable space always needs it, and so do most extensions. A building control body checks the work. If it is the council, you usually receive a completion certificate within 8 weeks of the work being finished. If it is a private registered building control approver, the approver gives the council a final certificate instead. Electrical, boiler and window work by an installer registered with a competent person scheme for that type of work is self-certified. Keep every certificate: without them you may not have the evidence of compliance you need when you sell.
Which home projects need approval
| Work | Building regulations approval |
|---|---|
| Loft conversion into a liveable space | Required |
| House extension | Required for most extensions. Some are exempt |
| Replacing windows, glazing units or a heating system | Can need approval, or is self-certified by an installer registered with a competent person scheme for that work |
| Electrical work around baths and showers, new fuse boxes | Not exempt. An electrician registered with a competent person scheme for electrical work can self-certify it |
| Most repairs and maintenance, replacing baths, toilets, basins and sinks, new power and lighting points or changes to existing circuits away from baths and showers, insulation in a roof space or under timber floors, gutters and downpipes, external doors less than half glazed | Not needed |
If you are not sure, GOV.UK advises asking a building control body before the work starts.
What building control checks
For a loft conversion the Planning Portal gives these examples: the structural strength of the new floor, the stability of the structure including the existing roof, safe escape from fire, safely designed stairs to the new floor and reasonable sound insulation between the conversion and the rooms below. For an extension it lists foundations, walls below ground, floors, ventilation, energy efficiency and structural openings, with drainage, electrics, doors and windows, walls, kitchens, bathrooms and roofs covered in its related pages. See our loft conversion and house extension pages for how these projects are built.
Who checks the work, and how
The building control body is either the council's building control department or a private registered building control approver. The two follow different procedures.
| Route | How it works | Certificate at the end |
|---|---|---|
| Council: full plans | The most thorough option. The council checks the drawings and gives a decision within 5 weeks, or 2 months with your consent | Completion certificate from the council |
| Council: building notice | Only for smaller projects. There is no formal approval of plans in advance, and work can start 2 days after the notice is submitted | Completion certificate from the council |
| Private registered building control approver | You and the approver give the council a joint initial notice under section 47 of the Building Act 1984, and the approver supervises the work | Final certificate, which the approver gives to the council under section 51 |
The completion certificate
Where the council checked the work, GOV.UK says you will usually get a completion certificate within 8 weeks of completion, as long as the work complies. Where a private approver supervised it, the approver's final certificate to the council plays that role. Together with the certificates from registered installers, these are the evidence that the work met the building regulations. GOV.UK warns that without approval you will not have the certificates of compliance you may need when you sell your home.
Competent person schemes
Tradespeople registered with a competent person scheme for the type of work they do, for example installers of windows or boilers and registered electricians, can self-certify that their work complies, so you do not apply for approval yourself. The installer gives you a certificate within 8 weeks of completion, and it shows up in solicitors' searches when you sell. KRAMAN Ltd is NICEIC approved and Gas Safe registered.
Work done without approval
- A local authority building control body can give retrospective approval, called regularisation, for work carried out without consent.
- Regularisation is only available for work done after 11 November 1985, and you may need to alter the work before the certificate is issued.
- The person doing the work can be prosecuted and fined if it does not comply, and the building control body can make you pay to put faulty work right.
Planning and party walls are separate
Building regulations approval does not replace planning permission, and you might need both. Whether a project needs a planning application is covered in our guide to permitted development and lawful development certificates. Work on or near a shared wall also needs notice under the Party Wall etc. Act 1996, explained in our party wall guide.
Frequently asked questions
Do I need building regulations approval for a loft conversion?
Yes. The Planning Portal states that building regulations approval is required to convert a loft or attic into a liveable space, even where the loft needs no planning permission. The checks cover the strength of the new floor, the stability of the structure and roof, safe escape from fire, safe stairs and sound insulation between the loft and the rooms below.
Does a house extension need building regulations approval?
Most do. The Planning Portal says most extensions of a property require approval under the building regulations, covering for example foundations, walls below ground, floors, ventilation, energy efficiency and structural openings.
What is a building regulations completion certificate and when do I get it?
It is the council's certificate that the finished work complies with the building regulations. Where the council checked the work, GOV.UK says you will usually get it within 8 weeks of completion, as long as the work complies. Where a private registered building control approver supervised the work, the approver gives the council a final certificate instead.
What if building work was done without building regulations approval?
A local authority building control body can give retrospective approval, called regularisation, for work carried out after 11 November 1985. You may need to alter the work before a regularisation certificate is issued. Work that does not comply can lead to a requirement to correct it or a fine.
Can my electrician or boiler installer sign off their own work?
Yes, if they are registered with a competent person scheme for that type of work. A registered installer can self-certify that the work complies, and gives you a certificate within 8 weeks of completion, which also shows up in solicitors' searches when you sell.
Is building regulations approval the same as planning permission?
No. They are separate, and a project may need both. Planning rules decide whether you may build, and the building regulations set the standards the work must meet.
Sources
- Building regulations approval, GOV.UK, with its pages How to apply, When you do not need approval and Use a competent person scheme
- Building Act 1984, Part II (sections 47 and 51: initial notice and final certificate), legislation.gov.uk
- Is building regulations approval needed for a loft conversion?, Planning Portal
- Is building regulations approval needed for an extension?, Planning Portal
This guide summarises the building regulations approval process for houses in England. It is general information. The building control body decides whether your work complies.
Planning an extension or loft conversion?
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