Building Regulations Approval Process UK

Building regulations exist to ensure that construction work meets minimum standards for safety, energy efficiency, accessibility, and structural integrity. If you are carrying out building work in England or Wales, you will almost certainly need building regulations approval. This guide explains the process, the two main routes to approval, and how to keep things moving without unnecessary delays.

What Are Building Regulations?

Building regulations are the minimum standards that building work must meet in England and Wales. They cover structural safety, fire safety, energy conservation, ventilation, drainage, electrical safety, accessibility, and other technical matters.

The regulations are set out in the Building Regulations 2010 (as amended) and supported by Approved Documents A through S, each covering a different technical area. The Approved Documents provide practical guidance on how to meet the requirements, though they are guidance, not mandatory methods. You can use alternative approaches if they achieve the same standard.

Building regulations are separate from planning permission. You may need one, the other, or both depending on the work. Planning permission deals with the use and appearance of buildings; building regulations deal with how they are constructed.

When Do You Need Approval?

Most building work requires building regulations approval. Common examples include:

• Building an extension or conservatory (most types)
• Loft conversions
• Internal structural alterations (removing load-bearing walls)
• New or replacement windows and doors (unless installed by FENSA-registered installer)
• Re-roofing (if structural changes are made)
• Electrical work (certain types in England)
• New heating systems or boiler replacements
• Drainage changes
• New bathrooms where drainage is altered

Some work is exempt, including most repairs and like-for-like replacements, some small detached buildings, and certain types of conservatory. Check with your local building control or an approved inspector if you are unsure.

Full Plans vs Building Notice

Full Plans Application

You submit detailed drawings and specifications to building control before work starts. They review the plans against the regulations and either approve them, request amendments, or reject them with reasons.

Advantages:

• You know before starting that your design complies
• Provides certainty for you and your client
• Approved plans can be useful evidence if there is a dispute later
• Required for some work (e.g. over or near public sewers)

Disadvantages:

• Takes longer to get started (typically 5-8 weeks for approval)
• Higher initial fees
• Need to produce detailed drawings upfront

Building Notice

You submit a building notice at least 48 hours before work starts. No plans are required. Building control inspects the work as it progresses and checks compliance on site.

Advantages:

• Quick to start - just 48 hours notice
• Lower upfront cost
• Less paperwork

Disadvantages:

• Risk of non-compliance discovered during construction, requiring costly changes
• No formal approval - relies on inspections
• Cannot be used for all types of work

For larger or complex projects, a full plans application is always recommended. The building notice route is better suited to straightforward domestic work where the builder is experienced with the relevant regulations.

Inspection Stages

Building control will want to inspect the work at key stages. You must notify them before proceeding past each stage. Typical notification stages include:

1. Commencement - notify before starting work
2. Excavation of foundations - inspect before pouring concrete
3. Foundation concrete - inspect the poured foundations
4. Damp-proof course - inspect before covering
5. Oversite/ground floor - inspect before laying floor
6. Drainage - inspect before backfilling (including pressure/air test)
7. Structural frame/steelwork - inspect before enclosing
8. Roof structure - inspect before covering
9. Insulation - inspect before boarding over
10. Pre-plaster - inspect before plastering covers structural elements
11. Completion - final inspection

Critical point: if you cover up work before it has been inspected, building control may require you to expose it for inspection at your cost. Always give adequate notice and wait for the inspection before proceeding.

Fees and Timescales

Building control fees vary by local authority and the type and scale of work. As a rough guide for 2026:

• Small domestic extension - £400 to £800 total (plan check + inspection fees)
• Larger extension - £600 to £1,200
• Loft conversion - £400 to £800
• New dwelling - £800 to £2,000+

Private approved inspectors may charge differently and often offer fixed fees. They can sometimes offer faster turnaround on plan checks.

Timescales:

• Full plans decision: statutory period is 5 weeks (extendable to 2 months by agreement)
• Building notice: work can start 48 hours after submission
• Inspections: typically within 24-48 hours of notification

Common Causes of Delay

• Incomplete applications - missing structural calculations, drainage layouts, or energy calculations causes the plan check to take longer
• Not notifying inspections - work proceeds past an inspection stage without notification, requiring exposure of covered work
• Non-compliant work - discovered during inspection, requiring redesign or rebuilding
• Drainage test failures - particularly common with older properties and connections to existing drainage
• Structural calculations delays - waiting for an engineer to produce calculations. Commission these early.

Getting Your Completion Certificate

When all work is finished and has passed final inspection, building control issues a completion certificate. This is a critical document. Without it:

• Solicitors will flag it when the property is sold, potentially delaying or collapsing the sale
• Mortgage lenders may refuse to lend against the property
• Insurance may not cover the work

If work was completed without building regulations approval, you can apply for a regularisation certificate. This is retrospective approval and typically costs more, as building control may need to carry out invasive inspections to check compliance.

Always obtain the completion certificate. File it safely with the property deeds. It is one of the most important documents relating to any building work.

Final Thoughts

Building regulations exist to protect the safety and wellbeing of building occupants. The approval process is straightforward if you plan ahead, submit complete applications, and communicate with building control. Treat them as allies, not obstacles. A good relationship with your building control officer makes the whole process smoother.