Building control: full plans, building notice, and what changed

Two routes in

A full plans application means drawings and calculations are submitted and formally checked before work starts. You get a decision, and a plans certificate. It is slower at the front and much faster afterwards, because the structural design has already been agreed rather than being argued about on site with the trench open.

A building notice means telling building control you are starting, then having the work inspected as it goes. There is no formal approval of the design, which is fine for straightforward work and a real risk on anything structural — if an inspector disagrees with what has been built, it comes out.

For anything with steels, foundations near trees or drains, or an unusual span, full plans is the route worth paying for.

What the inspector actually looks at

Building control inspects at set stages rather than continuously. On a typical extension that means excavation before concrete, foundation concrete, damp proof course and oversite, drainage before backfill, drains under test, structural steelwork and its protection, insulation before it is covered, and a final inspection.

Missing a stage is the common failure. Concrete poured over an uninspected trench can mean digging it out to prove what is underneath.

The Approved Documents

The Building Regulations set the requirements; the Approved Documents show one accepted way of meeting them. There are currently eighteen parts plus Regulation 7 on materials and workmanship, and a domestic extension typically engages eight or nine of them at once.

The parts, in full

• A Structure · B Fire safety · C Site preparation, contaminants and moisture
• D Toxic substances · E Resistance to sound · F Ventilation
• G Sanitation, hot water safety and water efficiency · H Drainage and waste
• J Combustion appliances and fuel storage · K Protection from falling and impact
• L Conservation of fuel and power · M Access to and use of buildings
• O Overheating · P Electrical safety · Q Security in dwellings
• R Infrastructure for electronic communications · S Electric vehicle charging
• T Toilet accommodation · Regulation 7 Materials and workmanship

What changed in 2023 and 2024

From 1 October 2023 the Building Safety Regulator became the sole building control authority for higher-risk buildings — residential buildings, hospitals and care homes at least 18 metres or seven storeys. Local authorities and private inspectors cannot act on those at all.

The same date brought duties that apply to everything, not just tall buildings: clients, designers, principal designers, contractors and principal contractors all now carry named responsibilities for compliance with the Building Regulations. It mirrors the CDM structure, and it means competence has to be demonstrable rather than assumed. A stricter definition of when work counts as commenced came in at the same time.

From 6 April 2024, private approved inspectors had to be registered as Registered Building Control Approvers, and individual inspectors as Registered Building Inspectors. An unregistered inspector's initial notice ceased. If someone offers to sign work off, they are on a register or they are not.

The completion certificate

The completion certificate is what proves the work was signed off, and it is what a buyer's solicitor asks for. It arrives after the final inspection, not before, and only if every stage was inspected and every outstanding item cleared.

Work that was never signed off does not become compliant by getting older. It becomes a regularisation application, at the current standard, with whatever opening up that requires.