Estiquote research · September 2026

Your postcode can nearly triple the cost of approving an extension

Council building control for the same 10 to 40 m² single-storey extension costs from £587 (Bridgend) to £1,584 (Islington) on current schedules, including VAT: a 2.7-fold difference. The typical council charges £840. London's median is £1,113, about 1.5 times the North's £737.

By Estiquote · Data collected 25 September 2026 from each council's published fee schedule

What we found

91 councils in England and Wales publish a full plans charge for a 10 to 40 m² extension. The typical (median) council charges £840, and the middle half charge between £736 and £1,008.
Dearest: Camden (£1,876, though its band runs to 60 m²), then Islington (£1,584) and Southwark (£1,473).
Cheapest current schedules: Bridgend (£587), then Conwy (£648) and Fylde (£660). Newport (£485) and Vale of Glamorgan (£540) are lower but date from 2014 and 2023; Hull (£577) does not say whether VAT is included.
Building notice can cost more: at 34 of the 79 councils that publish both, the building notice route costs more than full plans.
Scotland and Northern Ireland use national fee scales. In Northern Ireland a 20 to 40 m² extension costs £243; in Scotland fees follow the value of the work (£950 for a £50,000 job).

Median fee by region

Median full plans charge for a 10 to 40 m² single-storey extension, including VAT
Region	Median	Councils
London	£1,113	10
South East	£990	13
East of England	£922	8
South West	£896	11
North East	£810	8
East Midlands	£793	9
West Midlands	£790	8
North West	£716	10
Yorkshire and the Humber	£701	6
Wales	£666	8

Every council we checked

Select a column heading to sort. Each council links to its local cost page, and "schedule" links to the fee schedule we used.

Full plans charges including VAT; bands differ slightly between councils
Council	Region	Extension 10 to 40 m²	Loft up to 40 m²	Notes
Camden	London	£1,876	£1,406	band runs to 60 m²; schedule
Islington	London	£1,584	£1,782	schedule
Southwark	London	£1,473	£1,473	schedule
Redbridge	London	£1,320	£1,320	schedule
Waverley	South East	£1,280	£1,385	schedule
Runnymede	South East	£1,182	£1,182	schedule
Cornwall	South West	£1,140	£1,140	schedule
Oxford	South East	£1,125	£1,190	schedule
Hillingdon	London	£1,122	£1,109	schedule
Wandsworth	London	£1,104	£1,084	schedule
South Hams	South West	£1,095	£795	older or undated schedule; schedule
Teignbridge	South West	£1,095	£795	older or undated schedule; schedule
West Devon	South West	£1,095	£795	older or undated schedule; schedule
Richmond upon Thames	London	£1,069	£1,050	schedule
Watford	East of England	£1,065	£752	schedule
St Albans	East of England	£1,065	£752	schedule
Monmouthshire	Wales	£1,056	£1,056	schedule
West Berkshire	South East	£1,055	£1,055	schedule
Wokingham	South East	£1,055	£1,055	schedule
Stockport	North West	£1,050	£1,260	schedule
Stoke-on-Trent	West Midlands	£1,026	£1,026	older or undated schedule; schedule
Maidstone	South East	£1,023	£1,064	older or undated schedule; schedule
Bromley	London	£1,008	£1,224	schedule
Harrow	London	£994	£927	schedule
Windsor and Maidenhead	South East	£990	£1,092	schedule
Plymouth	South West	£973	£882	older or undated schedule; schedule
South Tyneside	North East	£970	£1,005	schedule
Gateshead	North East	£965	£1,028	schedule
Hart	South East	£960	£990	schedule
Rushmoor	South East	£960	£990	schedule
Herefordshire	West Midlands	£960	£960	schedule
Birmingham	West Midlands	£957	£752	schedule
Maldon	East of England	£947	£947	schedule
Folkestone and Hythe	South East	£942	£942	schedule
Colchester	East of England	£925	£1,075	VAT not stated; schedule
North Norfolk	East of England	£919	£1,056	schedule
Newcastle upon Tyne	North East	£918	£1,050	schedule
Bedford	East of England	£916	£1,011	schedule
Mid Devon	South West	£896	£896	schedule
North Devon	South West	£896	£896	schedule
Ceredigion	Wales	£886	£886	schedule
Erewash	East Midlands	£882	£857	VAT not stated; schedule
Havering	London	£859	–	schedule
Horsham	South East	£858	£858	schedule
Crawley	South East	£858	£858	schedule
Milton Keynes	South East	£840	£1,254	schedule
Sunderland	North East	£840	£960	schedule
Solihull	West Midlands	£830	£755	schedule
Bradford	Yorkshire and the Humber	£824	£946	schedule
Liverpool	North West	£822	£930	older or undated schedule; schedule
Exeter	South West	£800	£800	older or undated schedule; schedule
Blaby	East Midlands	£793	£947	schedule
Harborough	East Midlands	£793	£947	schedule
Hinckley and Bosworth	East Midlands	£793	£947	schedule
Melton	East Midlands	£793	£947	schedule
Oadby and Wigston	East Midlands	£793	£947	schedule
Rutland	East Midlands	£793	£947	schedule
Uttlesford	East of England	£786	£996	schedule
Bassetlaw	East Midlands	£786	£786	schedule
Northumberland	North East	£780	–	schedule
Pembrokeshire	Wales	£780	£780	schedule
Nottingham	East Midlands	£762	£730	schedule
Pendle	North West	£756	£700	schedule
Wiltshire	South West	£755	£755	schedule
Coventry	West Midlands	£750	£750	schedule
Leeds	Yorkshire and the Humber	£750	£800	older or undated schedule; schedule
Durham	North East	£743	£750	schedule
Kirklees	Yorkshire and the Humber	£737	£783	VAT not stated; older or undated schedule; schedule
Cheshire West and Chester	North West	£736	£752	schedule
Bristol	South West	£735	£735	schedule
Ribble Valley	North West	£718	£699	schedule
Wolverhampton	West Midlands	£714	£648	schedule
Wyre	North West	£714	£618	schedule
Bury	North West	£713	£508	older or undated schedule; schedule
Darlington	North East	£710	£800	older or undated schedule; schedule
Sandwell	West Midlands	£704	£657	schedule
Stockton-on-Tees	North East	£697	£937	VAT not stated; older or undated schedule; schedule
Bath and North East Somerset	South West	£696	£660	older or undated schedule; schedule
Gwynedd	Wales	£684	£684	schedule
Walsall	West Midlands	£672	£636	VAT not stated; schedule
Peterborough	East of England	£666	£672	older or undated schedule; schedule
Barnsley	Yorkshire and the Humber	£665	£655	schedule
Oldham	North West	£665	£712	schedule
Sheffield	Yorkshire and the Humber	£661	£661	schedule
Fylde	North West	£660	£660	schedule
Blackpool	North West	£654	£673	schedule
Conwy	Wales	£648	£648	schedule
Bridgend	Wales	£587	£690	schedule
Hull	Yorkshire and the Humber	£577	£588	VAT not stated; schedule
Vale of Glamorgan	Wales	£540	£630	older or undated schedule; schedule
Newport	Wales	£485	£560	older or undated schedule; schedule

Method and caveats

We read each council's published building control charges in September 2026 and recorded the full plans charge (plan plus inspection) for a single-storey extension of 10 to 40 m², including VAT. Where a schedule showed prices without VAT we added 20%. Bands differ (some councils use up to 30 m² or 20 to 60 m²), 16 schedules carry no date and a few are older than 2025. Private approved inspectors set their own prices. Councils that only quote on request are not included.

Download the full dataset (CSV). Free to reuse with credit to Estiquote (CC BY 4.0).