Building regulations: what renovators need to know

Building regulations set the standards your work has to meet, and building control is the body that checks it. Almost every structural, electrical, plumbing, drainage, insulation or window job in a renovation is notifiable, and the paperwork you want at the end is a completion certificate. In England you are entitled to one in all cases where the authority is satisfied the work complies, within eight weeks of your completion notice.

That last point matters, because plenty of homeowners are told a certificate depends on which route they chose. In England it does not.

Building regulations are not planning permission

Two separate consents, checked by different people, for different reasons.

Planning permission is about whether you may change the appearance and use of a building, judged against local policy. Building regulations are about whether what you build is safe and performs properly, judged against national technical standards. You can have permitted development rights, meaning no planning application at all, and still need full building control approval.

They are also enforced differently, with different consequences. Our guide to the difference between the two consents sets out which one bites when.

Which parts apply to which work

The regulations are divided into Parts, each with an Approved Document giving guidance on how to satisfy it. The Approved Document is guidance rather than law: you must meet the requirement, and following the guidance is the usual way to prove you have.

The competent person route is worth knowing. For electrics under Part P, and windows under FENSA or CERTASS, a registered installer can self-certify and issue the certificate directly, and no separate building control application is needed. That is why a new consumer unit does not usually involve the council, and why you should keep the installer's certificate.

The standard for work on an existing building is lower than you think

New build has to meet current standards. An existing house does not, and this is one of the most useful things to understand.

Regulation 4(3) sets the test for work to an existing building: where the building did not comply before, the work must not make it more unsatisfactory than it was. So renovating a Victorian terrace does not oblige you to bring the whole house up to 2026 standards. It obliges you not to make things worse.

Two practical consequences. Building control cannot require you to upgrade parts of the house you are not touching. And the parts you are touching are judged in that context, which is why an old solid wall being replastered is treated differently from a new external wall.

There is an exception that catches people, and it is Part L. Strip an external wall back to brick across more than half its area and you are renovating a thermal element, which brings an upgrade expectation with it. Our guide to what plastering a house costs covers where that line sits.

Who actually checks the work, and what changed

This is the part where most guidance is out of date, so it is worth getting the words right.

Building control can be done either by your local authority or by a private registered building control approver, which is the term that replaced "approved inspector" under Part 3 of the Building Safety Act 2022. The individuals doing the inspecting are registered building inspectors, a category that did not previously exist, and they are registered in one of four classes according to what work they are competent to oversee.

The registers are kept by the Building Safety Regulator. As of 27 January 2026 the Building Safety Regulator is a standalone body sponsored by the Ministry of Housing, Communities and Local Government, having previously sat within the Health and Safety Executive.

What that means for you as a homeowner is simple and worth doing. Ask who your building control body is, and if it is a private approver, check it appears on the public register of registered building control approvers on GOV.UK. Ask for the name of the inspector. An answer that uses the phrase "approved inspector" is not necessarily a red flag, because the trade still says it, but a body that cannot tell you its registration is one.

Separately, since 1 October 2023, Part 2A of the regulations has imposed competence duties. Anyone carrying out design or building work must have the necessary skills, knowledge, experience and behaviours, refusing work beyond their competence is a required behaviour, and on a domestic project the duty to check that competence sits with your builder rather than with you.

The process, and the notices in it

The sequence is set out in regulation 16, and it changed with the 2023 reforms.

You give notice of intention to start work, and at least two days must elapse from the end of the day that notice is given before work begins. A commencement notice follows within five days.

The authority then has four weeks to reject the commencement notice with reasons. If it says nothing for four weeks, commencement is accepted. There is a right of appeal to the First-tier Tribunal within 21 days.

Here is the thing most articles get wrong. The old familiar list of fixed inspection stages, excavation, foundations, damp-proof course, drains before covering, is no longer a statutory list in England. Under the current regulation 16 the authority tells you in writing which stages it wants notifying, and only where it actually intends to inspect, based on its own assessment of the risk of a breach. It can also specify a period during which work must not be covered up.

So the honest answer to "when will building control visit" is: when they tell you they will. Get that list in writing at the start, because it is specific to your job rather than universal. Our guide to what building control actually inspects covers what happens on site.

At the end, a completion notice goes in within five days of finishing, and it must be accompanied by a compliance statement signed by the client, plus signed statements from the principal contractor and principal designer.

What it costs

Councils set their own charges under the Building (Local Authority Charges) Regulations 2010 on a cost-recovery basis, so there is no national fee.

Published schedules put a domestic extension up to 40 square metres at £700 to £1,300 including VAT across most of England. Inner London runs well above that: Tower Hamlets £1,551.60, Islington £1,584, Camden £1,875.55. Westminster does not publish an area band at all and prices by the value of the work instead.

Full plans and building notice cost the same in most authorities, so choosing between them is a question of how much certainty you want before you start, not of price.

Building control is one of several professional and statutory fees that never appear in a builder's quote. For where they all land against a project, see our guide to the renovation costs that catch people out.

The certificate, and why you want it

On completion the authority issues a completion certificate. In England regulation 17 requires one in all cases where, after taking all reasonable steps, the authority is satisfied the relevant provisions have been complied with, and it must do so within eight weeks of your completion notice.

Keep it. It is the document a buyer's solicitor asks for, and its absence is a routine reason for a sale to stall or a retention to be requested.

If work was done without approval, there is a route back. Regularisation under regulation 18 lets an owner apply retrospectively for work carried out on or after 11 November 1985, and the work is judged against the requirements in force when it was done rather than today's. Our guide to regularising unauthorised work covers what the council can require.

What happens if you skip it

Enforcement changed, and not in your favour.

Section 35 of the Building Act 1984 became an either-way offence through the Building Safety Act 2022, which removed the magistrates' time limit. The Planning Portal now states there are no time limits on prosecution. The old comfort that unauthorised work becomes safe after a couple of years no longer holds.

The practical consequences arrive earlier than any prosecution. A buyer's solicitor asks for the certificate. A surveyor recommends a specialist report. A lender makes it a condition. And an indemnity policy, which some people reach for, covers the risk of enforcement action only. It says nothing about whether the work is safe or of reasonable standard, and it can be void if the council has refused to certify the work, or even if you notify the council of the policy's existence.

How Beams helps

Building control is rarely the expensive part of a renovation and often the part that delays it, because the calculations, the notices and the inspection stages all sit on the critical path and none of them can be rushed at the end.

So we establish which Parts apply before the design is fixed, get the structural information produced early enough that building control is never waiting on it, and make sure the notices and the certificate are somebody's job rather than nobody's. Every builder then prices from the same information.

That is part of what a Beams project puts in writing: one agreed price, payments released against milestones, and 12 months on the workmanship.

Common questions

Do I need building regulations approval if I have permitted development rights?
Yes. They are separate consents. Permitted development removes the need for a planning application and has no effect at all on building regulations.

What is the difference between a building notice and full plans?
Full plans means your drawings and calculations are checked before you start, so you know they are acceptable. A building notice means you proceed and are inspected as you go. Most authorities charge the same for both, so the choice is about certainty rather than cost.

Can my builder handle building control for me?
Usually yes, and it is normal for them to. It remains worth knowing who the building control body is and asking to see the completion certificate at the end, because the certificate belongs to the property rather than to the builder.

Is a completion certificate the same as a certificate from my electrician?
No. A Part P certificate from a registered electrician, or a FENSA certificate for windows, covers that specific work through the competent person route. A completion certificate covers the notifiable building work as a whole.

How long does building control approval take?
On the full plans route, expect a few weeks for the check. On a building notice you can start after the statutory notice period, which is two clear days from the end of the day you give notice, with a commencement notice within five days. The authority then has four weeks to reject that notice.

Where this information comes from

The requirements, Parts and Approved Documents: The Building Regulations 2010 and the Approved Documents published on GOV.UK

Standard for work to existing buildings: regulation 4(3)

Competence duties: Part 2A, in force 1 October 2023

Notices, commencement, inspection stages and completion notices: regulation 16, as currently in force in England

Completion certificates, including the requirement in all cases and the eight-week period: regulation 17(1) and 17(2), as currently in force in England

Regularisation: regulation 18

Registered building control approvers and registered building inspectors: Building Safety Act 2022, Part 3, and the GOV.UK register of registered building control approvers in England

Building Safety Regulator as a standalone body sponsored by MHCLG from 27 January 2026: the Building Safety Regulator (Establishment of New Body and Transfer of Functions etc.) Regulations 2026

Enforcement: Building Act 1984 section 35, as amended by the Building Safety Act 2022, and Planning Portal guidance

Charges: Building (Local Authority Charges) Regulations 2010, and published fee schedules for Camden, Islington, Tower Hamlets, Southwark, Greenwich, Redbridge, Sutton, Hounslow, Ealing, Havering, Wandsworth, Hillingdon, Bromley, Lambeth, Harrow, Hackney and Westminster

Regulations differ in Wales, and the inspection stage provisions in particular are not the same. This page describes the position in England.