West Midlands
Building Regulations for rear extensions in the West Midlands
Construction drawings, structural calculations and building control through to the completion certificate. We design and build rear extensions across the West Midlands, from Birmingham and Coventry to Wolverhampton, covering single-storey kitchen extensions, two-storey additions, side returns and wraparounds.
Red-brick terraces and 1930s semis make up much of the West Midlands. Many already have a small kitchen lean-to at the back, which a new rear extension usually replaces rather than adds to.
What does it cost in the West Midlands?
As a guide, £2,500–£5,500 including VAT. Your written price follows a measured survey and an agreed design, so it reflects your house, not an average.
What approvals does it need in the West Midlands?
Every rear extension in England needs Building Regulations approval, whether or not planning is needed. You can use the council's building control service or a registered building control approver, by full plans (checked before work, usually within five weeks) or a building notice, and you get a completion certificate at the end.
New fabric must meet Approved Document L (2021 edition incorporating 2023 amendments): walls 0.18, roof 0.15 and floor 0.18 W/m²K, windows 1.4 W/m²K or Band B. Under the simple route, new windows, doors and rooflights should not exceed 25% of the extension floor area plus any openings removed; more glass is possible with a whole-house calculation.
Conservation areas, National Parks, National Landscapes and the Broads restrict permitted development, and listed buildings always need listed building consent.
Where in the West Midlands do we work?
- Birmingham
- Coventry
- Wolverhampton
- Dudley
- Walsall
- Solihull
- Sutton Coldfield
- West Bromwich
- Halesowen
- Stourbridge
- Smethwick
- Willenhall
- Tipton
- Bloxwich
- Wednesfield
- Washwood Heath
- Aston
- Shirley
- Brierley Hill
- Aldridge
- Acocks Green
- Bartley Green
- Wednesbury
- Kingswinford
- Hockley
- Wombourne
- Brownhills
- Chelmsley Wood
- Streetly
- Pelsall
- Oldbury
- Knowle
- Castle Vale
FAQ
Questions people ask
Full plans or building notice?
Full plans for most extensions: the design is checked before work starts. A building notice suits only simple jobs.
Who inspects the work?
The council's building control team or a registered building control approver (in Scotland, the council's building standards team).
What is a completion certificate?
The document confirming the work meets the regulations. Keep it; buyers' solicitors ask for it.
Do you cover all of the West Midlands?
We cover 33 towns and districts in the West Midlands, including Birmingham, Coventry and Wolverhampton.
Who builds the extension?
Vetted building teams working under contract to us; your contract is with S&K Property Investments and Improvement Ltd.