Building control explained: building notice vs full plans

What building control actually is

Building regulations set minimum standards for structure, fire safety, insulation, ventilation, drainage and electrics. Building control is the checking process: someone reviews your plans and inspects the work at key stages to confirm it meets those standards.[1]

You can use your local council's building control team or a private registered building control approver (formerly called an approved inspector). Both charge fees and both can issue the final certificate. Your builder cannot self-certify the whole job — although electricians, gas engineers, window installers and some other trades can certify their own work through competent person schemes, which avoids a separate inspection for that element.[1]

Work that normally needs building regulations approval includes extensions, loft and garage conversions, removing or altering load-bearing walls, new windows, replacing a boiler, and most work on drainage or electrics. Like-for-like repairs and small detached outbuildings are usually exempt.[1]

Building notice vs full plans: which route?

These are the two ways to apply, and choosing between them is one of the most common homeowner questions.

Rule of thumb: if the project involves structure, a designer is already producing drawings, or you may sell or remortgage within a few years, full plans is usually the safer route. The building notice saves time only when the work is simple and the builder knows exactly what the inspector will expect.[1]

What building control fees look like in 2026

Fees are set locally by each council (or quoted by private approvers), so there is no single national price. Indicative ranges for typical homeowner projects:

• Single-storey extension: roughly £400–£900, often split into a plan fee and an inspection fee.
• Loft conversion: roughly £450–£950, reflecting the extra structural and fire-safety checks.
• Internal structural alteration (for example removing a load-bearing wall): roughly £250–£600.
• Regularisation (certifying work already done without approval): typically 20–50% more than the standard fee, and not all work can be regularised.

These are indicative 2026 ranges, not quotations — check your own council's published fee schedule or get a quote from a registered approver. Fees are usually paid directly by you, not through the builder, so keep them in your project budget alongside design and structural engineer costs.[3]

The inspection stages your builder must book

Whoever is doing the work must notify building control at set stages — miss one and the inspector can ask for completed work to be opened up. The typical sequence for an extension or conversion:

1. Commencement — notice before work starts (and again if work stops for long periods).
2. Excavation and foundations — before concrete is poured, so ground conditions can be checked.
3. Damp-proof course and oversite — before the floor goes down.
4. Drainage — before new drains are covered over, plus a test.
5. Structural elements — steel beams, roof structure and floor joists before they are hidden.
6. Insulation and first fix — before plasterboard closes everything in.
7. Completion — the final visit that leads to the certificate.

Put the inspection stages in writing in your agreement with the builder, and make clear who books each visit. A good builder treats inspections as routine; resistance to them is a warning sign.[3]

The completion certificate — the document that matters when you sell

After a satisfactory final inspection, the council issues a completion certificate (or the approver issues a final certificate). This is the document solicitors ask for when you sell or remortgage. Its absence does not prove the work is wrong, but it raises questions that can delay or reduce a sale.[1]

• Chase the certificate as soon as the final inspection passes — do not assume it arrives automatically.
• Keep it with the planning documents, warranties and certificates from competent person schemes (electrics, gas, windows).
• If work was done without approval, the route back is a regularisation application — possible only for work carried out after November 1985, and it may involve opening up finished work.

Five things to do before work starts

1. Confirm what approvals your project needs — planning permission and building regulations are separate; you may need one, both or neither.
2. Choose your route — building notice for simple work, full plans for anything structural or complex.
3. Decide council vs private approver — compare fees and availability; either can certify the work.
4. Put inspections in the contract — agree who books each stage visit and that no stage gets covered up before sign-off.
5. Budget for the fees — add building control, structural engineer and any design fees to your project total before comparing builder quotes.

Not sure whether your project needs planning permission as well? Try our free planning permission checker — five questions against 2026 permitted development limits.