If you are planning a kitchen extension, building regulations help make sure the finished space is safe, structurally sound, energy-efficient and properly built.
So, how long does building regulation approval take? For a full plans application in England, the building control body will normally make a decision within five weeks, although this can be extended to two months with your agreement. A full plans application is the route where detailed drawings, specifications and other technical information about the proposed work are submitted to Building Control for assessment before construction begins.
This allows the building control body to check whether the proposed work is designed to meet building regulations requirements.
With a building notice, there is no formal approval stage before work begins and work can usually start two days after submission.
The process then continues through construction, with inspections at key stages and a completion certificate at the end.
What Is Building Regulations Approval?
Building regulations approval is separate from planning permission. Planning is mainly concerned with what you can build and its effect on the surrounding area. Building regulations focus on how the work is designed and constructed.
For a home extension, this can include foundations, structure, drainage, fire safety, ventilation, insulation, electrical safety and energy performance. Even if an extension falls under permitted development, it will usually still need to comply with building regulations.
Factors That Affect How Long Building Regulations Approval Takes
If you are wondering how long building regulations approval takes in practice, it depends on the application route, project complexity, structural calculations, the quality of the submitted information and how quickly queries are answered.
Drainage, nearby trees, ground conditions or design changes can also lead to additional checks.
Full Plans Applications: Typical Timescales
How long does it take to get building regulations approval? The clearest answer usually relates to a full plans application.
Detailed drawings, specifications and calculations are submitted before the build. The building control body should normally issue a decision within five weeks. This can be extended to two months if you agree, giving the building control body additional time to assess the plans, request further information or resolve any technical issues before reaching a decision.
The main advantage is greater certainty before construction progresses, as key technical details have been checked in advance.
Building Notice Applications: How Long Do They Take?
A building notice is a simpler type of building regulations application that provides Building Control with notice of proposed work without requiring detailed plans to be submitted for approval beforehand. It is generally suitable for smaller projects where the work is relatively straightforward.
A building notice does not involve waiting for formal plan approval. For suitable smaller projects, work can usually begin two days after the notice is submitted.
However, this does not mean the project has been approved in advance. Building Control can request plans, calculations or other information while work is underway, and the project must still comply with the regulations.
How Long Do Building Control Inspections Take?
Building control inspections take place during construction, at stages such as foundations, drainage, structural work, insulation and completion.
Inspection arrangements vary between building control bodies, so there is no single nationwide turnaround time. If work is covered before Building Control has the opportunity to inspect it, this can cause delays or require areas to be opened up again.
How Long Does It Take to Receive a Completion Certificate?
Once the extension is finished, a final inspection is normally required. If the work complies and the required information has been supplied, GOV.UK says you will usually receive a completion certificate within eight weeks of completion.
Keep the certificate safely, as it may be important when you sell or remortgage the property.
How Long Does Retrospective Building Regulations Approval Take?
If work was carried out without the required approval, you may be able to apply for retrospective approval through a regularisation application.
There is no fixed national answer to how long retrospective building regulations approval takes. The local authority may need drawings, calculations, tests or inspections, and it can ask for parts of the work to be exposed. Any remedial work will add time.
Regularisation is available through local authority building control for eligible work carried out after 11 November 1985.
Common Reasons for Delays
Common causes include incomplete drawings, missing structural calculations, drainage issues, design changes and slow responses to technical queries. Covering up work before inspection can also cause problems.
How to Speed Up the Process
Make sure drawings and calculations are coordinated before submission and respond quickly if Building Control asks for changes or more information.
During construction, arrange inspections at the correct stages and avoid unnecessary design changes, particularly where they affect structure, drainage or fire safety.
Building Regulations Timeline for a Kitchen Extension
For a typical kitchen extension using the full plans route, the process may look like this:
- Technical drawings and structural calculations are prepared.
- The full plans application is submitted.
- Building Control reviews it, normally within five weeks.
- Questions or amendments are resolved.
- Construction begins and inspections take place at key stages.
- A final inspection is completed.
- A completion certificate is issued once requirements are satisfied.
Building regulations therefore run alongside the build itself. Initial approval is only one part of the process.
How a Design and Build Company Can Help
Building regulations are easier to manage when design, technical information and construction are coordinated from the beginning. A design and build company can prepare drawings, organise structural calculations, communicate with Building Control and arrange inspections at the right stages.
Plus Rooms offers a complete Extension Design and Build service for London homeowners, bringing design, planning and construction together in one coordinated process. This helps keep building regulations connected to the wider extension project, from the first ideas through to completion.
If you are considering a kitchen extension and would like to understand the likely process and timescales for your home, contact Plus Rooms for more information.
Frequently Asked Questions
Can I start building before building regulations are approved?
With a building notice, work can usually start two days after submission. With full plans, starting before a decision may be possible, but it carries more risk because the plans have not been formally approved.
Is building regulations approval the same as planning permission?
No. An extension may not need planning permission but can still require building regulations approval.
What happens if Building Control finds a problem?
The inspector may ask for more information or require work to be altered before it is covered or completed.
Do I need a completion certificate for an extension?
Yes, you should obtain one where Building Control is overseeing the work. It provides useful evidence that the finished work was inspected and found to comply.
