Building-Regs FAQ
How much do building regulations cost?
Council LABC: £400-£900 plans + inspection for a typical extension. Approved Inspector: comparable or slightly higher.
Council LABC: £400-£900 plans + inspection for a typical extension. Approved Inspector: comparable or slightly higher.
Building control charges are set by each authority or private approver, not nationally. For a typical London domestic extension or loft conversion, expect £500 to £1,200 including VAT, usually split between a plan-check charge and an inspection charge.
Five weeks for a full plans decision, or two months where the authority agrees it in writing. The completion certificate is due within eight weeks of the work finishing, and enforcement runs for ten years after that under section 36 of the Building Act 1984. Commencement notice is two days.
| Step | Statutory period | Source |
|---|---|---|
| Full plans decision | 5 weeks, or 2 months by agreement | Building Regulations 2010, reg 14 |
| Building notice before starting | at least 2 days | reg 12 |
| Notice of commencement | at least 2 days | reg 16 |
| Notice of completion | within 5 days | reg 16 |
| Completion certificate | within 8 weeks of completion | reg 17 |
| Enforcement time limit | 10 years from completion | Building Act 1984, s.36 |
Sources: the Building Regulations 2010 (as amended) and the Building Act 1984, read at 1 September 2026. Approved inspectors were renamed registered building control approvers under the Building Safety Act 2022, with the register operating from April 2024; a certificate from an unregistered inspector is not a valid completion certificate.
Local authority scales are normally banded — by floor area for extensions and by estimated cost of works for everything else. A single-storey rear extension under 40 m² sits in the cheapest band; a loft plus rear extension crosses into a higher one. Private approvers quote per project and price on complexity rather than a published scale.
A full plans application takes the plan charge on submission and the inspection charge either at first inspection or in instalments. A building notice takes the whole charge up front. A regularisation application for unauthorised past work costs materially more than the equivalent normal fee.
Any SAP or energy assessment. Air pressure testing where required. Specialist reports. And the cost of opening up work that was covered before inspection — which is entirely avoidable by booking inspections at the right stage.
Planning is £548 for a householder application. Party wall awards commonly run £900 to £1,400 per neighbour. Building control is usually the second largest statutory cost after the build itself.
How much do building regulations cost? in a Hackney context: London Borough of Hackney (Hackney Council) runs 29 conservation areas including the De Beauvoir Town Conservation Area and the Stoke Newington Conservation Area, and an Article 4 direction is in force there, so permitted development cannot be assumed. That decides how how much do building regulations cost? is handled: £548 and 8 weeks for a Hackney householder application, or £274 for the Lawful Development Certificate that records how much do building regulations cost? as lawful. The law behind how much do building regulations cost? sits in the Town and Country Planning Act 1990, the GPDO 2015 and the Building Regulations 2010.
| Typical London range | £500–£1,200 incl. VAT |
|---|---|
| Set by | Each authority or approver |
| Usual split | Plan charge + inspection charge |
| Regularisation | Higher than the standard charge |
| Planning fee, separate | £548 |
| Structural calculations |
No. Each authority publishes its own scale.
Local authority charges include VAT; private approvers add it.
Usually yes — the plan charge on submission and the inspection charge later.
Pick a slot that suits you. No obligation and no sales pressure, just straight answers on your planning route.
