How much does building control cost for an extension? 33 councils compared

Building notice fees run from £499.20 in Chorley to £1,265 in Wigan including VAT across the 26 comparable council tables whose bands top out at 40 m². The median is £846.38. Seven wider bands sit outside those figures; with them, the top is Redbridge’s £1,320 for “exceeds 20m2 but does not exceed 60m2”.

Full plans means submitting drawings for the council to check and decide on before you build. A building notice means telling the council and starting without plans checked in advance. Measure floor area to the finished internal faces of the walls around it: that area decides the fee band. The route your job needs decides which column applies; building control for the trades sets out the routes.

How much does building control cost for an extension, council by council

Seven rows use bands ending beyond 40 m², so the size column governs comparisons. The sample is neither representative nor random: it covers accessible English council tables read on 6 October 2026, with a stated 2026 effective date in the table or linking page. Wales, Scotland and Northern Ireland operate separate systems.

Full plans shows plan plus inspection charges: add the two to compare with building notice. One charge means an unsplit amount. Paid together is the council’s price for paying both on submission. The bands are copied as each council writes them, typos included.

Building control fees for a single storey extension in 33 English councils, 2026 tables read on 6 October 2026, VAT included unless marked

Council	Region	Size band, as written	Full plans	Building notice
Adur and Worthing	South East	15m2 to 60m2	£326.46 + £761.74	£1,305.84
Barnsley	Yorkshire	over 10m² and up to 40m²	£270 + £395	£665
Bassetlaw	East Midlands	exceeding 20 m2 but less than 40 m2	£258 + £528	£785
Bradford	Yorkshire	10m² > but < 40m²	£262.51 + £561.22	£991.73
Bristol	South West	up to 40m2	£255 + £480 (£700 paid together)	£700
Cherwell	South East	exceeds 10m2 but does not exceed 40m2	£930 (one charge)	£1,023
Cheshire West and Chester	North West	between 10-40 sqm	£234.82 + £501.50	£846.77
Chorley	North West	over 5m² but not exceeding 40m²	£187.20 + £312	£499.20
Coventry	West Midlands	less than 40m2	£325 + £425	£750
Durham	North East	between 10m² and 40m²	£248 + £495	£744
Havering	London	exceeds 30m2, but does not exceed 60m2	£1,183 (one charge)	£1,183
Herefordshire	West Midlands	over up to 40m²	£960 (one charge)	£960
Hull	Yorkshire	under 60m2	£150 + £427 (VAT not stated)	£577 (VAT not stated)
Luton	East	under 100m²	£375 + £700 (£1,045 paid together)	£1,290
Maldon	East	not exceeding 40m²	£315.60 + £631.20	£1,040.40
Newcastle	North East	exceeding 10m2 but not exceeding40m2	£276 + £642 (£846 paid together)	£846
North Norfolk	East	not exceeding 100m2	£342 + £577.20 (£889.20 paid together)	£889.20
North Tyneside	North East	between 10m2 and 40m2	£283.50 + £590.10	£873.60
Oxford	South East	10m2 to 40m2	£1,125 (one charge)	£1,125
Pendle	North West	over 6 m2 But not exceeding 40 m2	£756 (one charge)	£907
Redbridge	London	exceeds 20m2 but does not exceed 60m2	£1,320 (one charge)	£1,320
Ribble Valley	North West	over 6m2 but not exceeding 40m2	£300 + £418	£823
Richmond upon Thames	London	<40²	£427.60 + £641.40	£1,069
Runnymede	South East	10m2 to 40 m2	£1,182 (one charge)	£1,182
Sandwell	West Midlands	greater than 10m2 and up to 40m2	£328.51 + £375.40	£844.78
Sefton	North West	Less than 40m²	£306 + £408	£714
Sevenoaks	South East	less than 40m²	£360 + £660	£1,020
Solihull	West Midlands	≤ 40m2	£250 + £580	£830
Walsall	West Midlands	Between 10m2 and 40m2	£329 + £343	£805
West Northamptonshire	East Midlands	10m2 to 40m2	£191.75 + £528.50	£720
Wigan	North West	exceeding 10m2 but not exceeding 40m2	£445 + £535	£1,265
Windsor and Maidenhead	South East	10m2-40m2	£432 + £558	£1,138.50
Wyre	North West	not exceeding 60m2	£714 (one charge)	£714

Where a council’s figure assumes a registered (Part P) electrician, the table shows that figure; Barnsley adds £380 and Wigan £570 if not. Both figures include VAT.

Hull’s table does not say whether its figures include VAT; ask Hull before quoting its row.

Above the guide prices in 21 of 26 comparable tables

Building notice costs more than £720 in 21 of the 26 comparable rows. Homebuilding & Renovating’s guide of 14 August 2024 gives around £600 plus VAT for a 10 to 40 m² extension, or £720 at 20% VAT.

Book a Builder UK’s 2026 checklist gives £500 to £1,000 for a 20 m² single storey rear extension outside London. Building notice exceeds £1,000 in seven of the 25 comparable rows outside London. Only Chorley falls below £500.

The three London councils in the sample charge £1,069 to £1,320 for a building notice.

Whito’s guide, updated 17 September 2026, gives £100 to submit full plans plus £200 to £400 for inspections, citing HomeOwners Alliance. Its building control line does not say whether VAT is included. Every separate plan charge in the sample exceeds £100. For inspections, 21 of 25 exceed £400 including VAT.

None of these guides cites a council fee table. Your charge comes from the council’s scheme under regulation 3.

Why each council sets its own price

Each council sets its charges from what its own service costs, using officer time at an hourly rate, with floor area and expected inspections among the factors. It reviews those charges every year.

How much of what to charge for the extension goes to building control depends on the band and the route. If your job needs an individually determined charge, regulation 7(7) requires the council to give you its amount and factors in writing.

Full plans in parts, building notice upfront

No route is always cheaper. Of the 25 split rows, building notice costs at least £5 more in ten and at least £5 less in three. Nine match exactly; Durham, West Northamptonshire and Bassetlaw differ by £1 or less.

In Newcastle and Bristol, paying both full plans charges on submission removes the price gap. North Norfolk does the same. Luton charges £1,045 if paid together; building notice stays dearer at £1,290. Among the unsplit full plans rows, six match building notice. Pendle and Cherwell charge more for the notice.

How much you pay on submission differs by route. With full plans, the plan charge is paid then and the inspection charge on demand after the first inspection. A building notice is paid in full on submission.

Extra charges for electrical work and visits

Wigan adds £570 including VAT to the inspection or building notice charge for notifiable electrical work without a Part P registered electrician. Its 2026/27 table, effective 1 April 2026, applies this to the “exceeding 10m2 but not exceeding 40m2” band.

Solihull’s supplementary schedule, effective 1 April 2026, lists £130 an hour including VAT. It names extra site visits among the reasons a supplement may arise.

If the job takes more officer time than the charge assumed, the council can add a supplement; if it needs less, it must refund the difference. The council explains refunds and supplements in writing, and supplies its calculation with a supplement.

Before you price the job, search for your council’s name plus “building control charges” to find its 2026 charging scheme. Taking the building notice or full plans figure for the extension’s band into your quote with VAT is part of running the business.

Awaiting Parliamentary approval for wider charges

Across England, the proposed building control fees reform would allow councils to charge for more functions on a fuller cost-recovery basis, subject to Parliamentary approval, according to MHCLG’s letter of 10 September 2026, read on 6 October 2026. No amounts or start date had been published by 6 October 2026.