Extensions in Birmingham: design, planning and build
We design and build house extensions for homes in Birmingham and the surrounding West Midlands area, with guide prices adjusted for the region.
- Postcode districtsB1, B2, B3, B4, B5, B19
- Price regionWest Midlands (×0.97)
- Planning rulesEngland
- Site visitFree, no obligation
What works best for Birmingham houses?
The West Midlands has a large stock of 1930s and post-war semi-detached houses, which are well suited to rear, side and over-garage extensions, plus Victorian terraces in the older inner areas.
For many houses here, kitchen extensions, extensions over a garage or single-storey rear extensions gives the most useful space for the budget.
Planning rules in Birmingham
In England a single-storey rear extension can usually go up to 3 m beyond the original rear wall of a semi-detached or terraced house, or 4 m on a detached house, without a planning application, provided it is no more than 4 m high, keeps eaves to 3 m within 2 m of a boundary and, with other buildings, covers no more than half the land around the original house. The larger home extension prior approval scheme raises those depths to 6 m and 8 m, with neighbours notified and a 42-day decision.
In England a two-storey rear extension is permitted development only if it projects no more than 3 m from the original rear wall, sits at least 7 m from the rear boundary, matches the roof pitch and uses obscure, non-opening side windows upstairs. Most two-storey extensions therefore go through a householder planning application, which costs £548 from 1 April 2026 and normally takes about 8 weeks.
In a conservation area, national park, National Landscape, the Broads or a World Heritage Site the permitted development limits are tighter (no side or two-storey extensions without an application). Listed homes need listed building consent, and if permitted development rights have been removed, any extension needs an application.
If the work involves a shared wall, building on the boundary, or digging foundations within 3 m (sometimes 6 m) of a neighbour's building, the Party Wall etc. Act 1996 applies and notice must be served before work starts: two months for work to a party wall, one month for new walls on the boundary and for excavations.
Applications are decided by the local planning authority (your district, borough or unitary council).
Areas we cover around Birmingham
Postcode districts we cover around Birmingham include B1, B2, B3, B4, B5, B19. We also work in nearby Smethwick (3 miles), West Bromwich (5 miles), Shirley (6 miles), Halesowen (7 miles), Solihull (7 miles). Bromsgrove, in Worcestershire, is roughly 12 miles from Birmingham and also on our list.
Birmingham extension prices at a glance
We publish guide prices so you can budget before anyone visits. For Birmingham they are adjusted by ×0.97, the factor we use across West Midlands.
| Extension type | Example size | Standard spec (inc VAT) |
|---|---|---|
| Orangery extensions | 16 m² | £43,000 – £54,500 |
| Side return extensions | 11 m² | £25,500 – £32,500 |
| Single-storey rear extensions | 20 m² | £39,500 – £50,500 |
| Kitchen extensions | 20 m² | £40,500 – £51,500 |
| Conservatory replacement extensions | 14 m² | £29,000 – £37,500 |
| Wraparound extensions | 25 m² | £55,500 – £70,500 |
| Extensions over a garage | 12 m² | £24,000 – £31,500 |
All extension types we build in Birmingham
- Conservatory replacement extensions · from £19,000
- Porch extensions · from £3,850
- Home office extensions · from £15,500
- Bedroom extensions · from £25,000
- Extension plans and drawings · from £1,150
- Kitchen extensions · from £26,000
- Bungalow extensions · from £25,000
- Extensions over a garage · from £23,000
- Utility and boot room extensions · from £13,500
- Single-storey rear extensions · from £20,000
- Timber frame extensions · from £20,000
- Side return extensions · from £17,000
- Annexe extensions · from £53,000
- Flat roof extensions · from £20,000
- Orangery extensions · from £29,000
- Double-storey extensions · from £36,500
- Wraparound extensions · from £34,500
- Side extensions · from £21,000
- Glass box extensions · from £29,000
- Building regulations for extensions · from £850
- Pitched roof extensions · from £21,500
- Planning permission for extensions · from £300
Free site visit
It starts with a visit to your house to measure, check access and talk through ideas and budget.
Design and approvals
We draw the design, agree it with you and handle planning or permitted development checks and building regulations.
Fixed written price
With the design and specification agreed, you get a fixed written price and a start date.
Build and sign-off
The build is managed from start to finish, inspected at each stage and signed off on completion.
Questions about extensions in Birmingham
How much does an extension cost in Birmingham?
Using our West Midlands factor (×0.97), a standard-spec single-storey extension of 20 m² is a guide £39,500 to £50,500 including VAT, and a 32 m² two-storey extension £55,500 to £73,000. Your written price follows the survey.
How long does an extension take in Birmingham?
Usually 2 to 4 months of design and approvals, then 10 to 16 weeks on site for a single-storey extension or 16 to 24 weeks for two storeys.
Will my neighbours need to be told?
If you apply for planning or prior approval the council notifies them, and in England party wall notices may be needed for work near a shared boundary.
Do I need planning permission for an extension in Birmingham?
Not always. It depends on the size, position and your property's history. Many single-storey rear extensions in England are permitted development or can use prior approval.
Book a free site visit in Birmingham
We will measure up, check the planning position and give you honest guide figures.
- Free, no-obligation site visit
- Planning route checked before you spend on drawings
- Written price once the design is agreed
- Building control sign-off at the end
Prefer to talk? Call 0800 088 6341 or .
Book a free site visit
Tell us a little about the project and we will arrange a time.