Hampstead Architecture and Planning

Building Regulations

Building Regulations Approval: Full Plans or a Building Notice?

Almost every building project needs building regulations approval, separately from planning permission. This guide explains the two routes — full plans and a building notice — who you apply to, and the completion certificate you will need when you sell.

Last updated 5 min read

Building regulations are not planning permission

Building regulations and planning permission are two separate approvals doing two different jobs. Planning is about whether you may make a change; building regulations are about how it is built — the structure, fire safety, insulation, drainage, ventilation and more. A project can need both, one, or (rarely) neither, and getting planning permission does not discharge the building regulations. Most extensions, loft conversions, structural alterations and conversions need building regulations approval.

The two routes: full plans and building notice

There are two ways to get building regulations approval. A full plans application submits detailed drawings and specifications that are checked for compliance before work starts; the authority must decide within five weeks (or up to two months by written agreement), and if work has not started within three years the authority can treat the deposited plans as no longer effective. A building notice is a lighter route for straightforward domestic work — you give notice and can start two days later, with the work inspected as it proceeds rather than approved in advance. A building notice cannot be used in a block of flats, or for other work subject to fire-safety consultation, and it carries more risk, because nothing is signed off before you build.

Who you apply to

Building control can be carried out either by the local authority’s building control team or by a private-sector registered building control approver (the role previously called an "approved inspector"). Either way, the building regulations drawings set out how the work complies, and the inspector checks the work at key stages on site. The choice of body does not change the standards — only who administers them.

The completion certificate

When the work is finished and has passed its final inspection, building control issues a completion certificate confirming it complies with the regulations. That certificate matters well beyond the build: a buyer’s solicitor will ask for it, and its absence can hold up or complicate a future sale. It is the reason building regulations should be treated as a proper part of the project — with the right route chosen and the drawings prepared to support it — rather than an afterthought on site.

Frequently asked questions

Do I need building regulations approval for my project?

Almost certainly, for most extensions, loft conversions, structural alterations and conversions. Building regulations are separate from planning permission and cover how the work is built safely and properly.

What is the difference between full plans and a building notice?

Full plans submits detailed drawings that are checked for compliance before work starts, with a decision in five weeks. A building notice is a lighter route for straightforward domestic work — you start two days after notifying, with the work inspected as it proceeds and no approval in advance.

Can I use a building notice for a flat?

No. A building notice cannot be used in a block of flats, or for other work subject to fire-safety consultation; a full plans application is required.

Who carries out building control?

Either the local authority’s building control team or a private-sector registered building control approver (formerly an "approved inspector"). Both apply the same standards.

What is a completion certificate and why does it matter?

It is issued by building control when the finished work passes its final inspection, confirming it complies with the regulations. A buyer’s solicitor will ask for it, so a missing certificate can complicate a future sale.

Is building regulations approval the same as planning permission?

No. Planning permission is about whether you may make a change; building regulations are about how it is safely built. A project can need both, and planning permission does not discharge the building regulations.

Need drawings or planning advice for your property?

Tell us the property address, type and what you are considering. We will advise the likely route — planning, building regulations, or both — and what information will be needed.

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