A building control officer (BCO) is a qualified inspector who checks that notifiable building work complies with the Building Regulations - the legal minimum standards for construction in England and Wales covering structural safety, fire safety, energy efficiency, ventilation, drainage, accessibility and more. For most projects requiring Building Regulations approval you can choose between local authority Building Control (LABC) and a private Registered Building Inspector (approved inspector). Both check the same standards but private inspectors often offer faster turnaround times and more proactive site engagement.
What they do
- Accept building notice or full plans submissions for notifiable work
- Review and approve structural calculations and drawings
- Carry out site inspections at key stages (foundations, drainage, frame, etc.)
- Issue completion certificates on satisfactory completion
- Advise on compliance during design and construction
- Process regularisation applications for work done without approval
- Issue determinations on novel or uncertain compliance questions
- Liaise with architects, structural engineers and contractors
When you need one
Most significant building work requires Building Regulations approval. The following work is notifiable and requires you to engage Building Control before starting.
Typical fees (UK, 2025)
| Service | Typical cost |
|---|---|
| Building notice - domestic extension | £300 - £700 |
| Full plans application fee | £400 - £1,000 |
| Private approved inspector fee | £400 - £1,200 |
| Completion certificate (retrospective) | £600 - £1,500 |
| Regularisation certificate | £500 - £1,200 |
| Specialist advice (hourly rate) | £70 - £120 / hr |
Local authority fees are set by statutory charge; private inspector fees are negotiated. For larger or commercial projects, get quotes from both LABC and private inspectors - savings can be significant.
Qualifications to look for
The primary professional body for building control surveyors. MCABE members working in building control are assessed for competence in the Building Regulations. Check membership at cbuilde.com.
From October 2023 all building inspectors in England must be registered with the Building Safety Regulator. Class of registration (1-3) determines which types of project they can oversee. Higher-risk buildings (HRBs) require a Class 3 inspector.
Chartered surveyors with building control specialism may also act as Registered Building Inspectors. RICS members working in building control must also hold RBI registration from the Building Safety Regulator.
How to find a building control service
Frequently asked questions
What is the difference between a building notice and full plans?
A building notice is a simpler notification to Building Control allowing work to start after 48 hours without submitting full drawings - suitable for straightforward domestic work such as internal alterations. Full plans involves submitting detailed drawings for approval before work starts - this takes longer (5 weeks for standard applications) but gives more certainty that the design complies with Building Regulations before work begins.
Do I need Building Regulations for a bathroom?
Moving an existing bathroom or replacing fittings like-for-like does not usually require Building Regulations. However, adding a new bathroom involving new drainage connections does require approval under Part H of the Building Regulations. Adding a bathroom to a loft conversion also requires approval as part of the loft conversion itself.
What happens if I do work without Building Regulations approval?
You may be unable to sell the property without a regularisation certificate or indemnity insurance. The local authority can require you to open up the work for inspection or to reinstate what was removed. There is no time limit on enforcement of Building Regulations contraventions (unlike planning enforcement). If you are buying a property with unauthorised building work, your solicitor should advise on the options including indemnity insurance or applying for a regularisation certificate.