Castle Vale, West Midlands
Semi-detached rear extension in Castle Vale
Thinking about a semi-detached rear extension in Castle Vale? Single or two-storey extensions for semi-detached houses, with side access and one party wall. Our team handles the drawings, the planning route and the build, and your contract is with one company throughout.
We cover Castle Vale (B24, B34 and B35) as part of our West Midlands work. Where a Castle Vale semi already has a small lean-to at the back, we usually replace it rather than extend it.
Book a free site visit
Tell us about the house and we'll call to arrange a free, no-obligation visit.
How much does a semi-detached rear extension cost in Castle Vale?
In Castle Vale, our guide for a semi-detached rear extension is £1,900–£3,100 per square metre including VAT for a standard specification. The West Midlands is the baseline for our guide prices.
| Size | Guide price inc VAT |
|---|---|
| 3 m wide × 4 m deep (12 m²) | £23,000–£37,000 |
| 4 m wide × 5 m deep (20 m²) | £38,000–£62,000 |
| 4 m wide × 6 m deep (24 m²) | £45,500–£74,500 |
We put a fixed price in writing once the design is agreed, and explain any provisional sums such as foundations.
Do you need planning permission for a semi-detached rear extension in Castle Vale?
The planning route for a semi-detached rear extension in Castle Vale is set by England's householder rules and your council.
In England a single-storey rear extension can often be built under permitted development: up to 3 metres beyond the original rear wall of an attached house, or 4 metres on a detached house, no higher than 4 metres, with eaves no higher than 3 metres if any part is within 2 metres of a boundary.
A two-storey rear extension can be permitted development in England only if it projects no more than 3 metres, stays at least 7 metres from the rear boundary, matches the existing roof pitch and has obscure-glazed upper side windows. In practice most double-storey rear extensions go through a householder planning application.
England also has the larger home extension route: a single-storey rear extension of up to 6 metres on an attached house or 8 metres on a detached house, after prior approval from the council. The council notifies your neighbours and has 42 days to decide; the fee is £249 (£310 for applications made from 8 December 2026). The route is not available on designated land such as conservation areas.
Conservation areas, National Parks, National Landscapes and the Broads restrict permitted development, and listed buildings always need listed building consent. At the first visit we measure what is there now and tell you which route fits: permitted development, prior approval or a planning application.
What are homes in Castle Vale like to extend?
Red-brick terraces and 1930s semis make up much of Castle Vale. Many already have a small kitchen lean-to at the back, which a new rear extension usually replaces rather than adds to.
How a semi-detached rear extension in Castle Vale comes together
Survey visit
We visit free of charge, measure up, check access, drainage and neighbours' extensions, and note what you want the room to do.
Options and costs
We draw layout options and price each one, so the budget shapes the design rather than surprising you later.
Approvals
Permitted development check, prior approval or planning application, then Building Regulations drawings and structural calculations, plus party wall notices where they apply.
Fixed price and build
A written price for the agreed design, a start date and a named contact through the build, ending with the building control completion certificate.
Semi-detached rear extensions near Castle Vale
We also build rear extensions for semi-detached houses in nearby Washwood Heath (1.8 miles) and Sutton Coldfield (3.4 miles).
- Semi-detached rear extension in Washwood Heath
- Semi-detached rear extension in Sutton Coldfield
- Semi-detached rear extension in Chelmsley Wood
- Semi-detached rear extension in Aston
- Semi-detached rear extension in Acocks Green
Other work in Castle Vale:
FAQ
Semi-detached rear extension questions in Castle Vale
What postcode areas do you cover around Castle Vale?
Including B24, B34 and B35, and the surrounding West Midlands area.
Can I live at home while the extension is built?
Usually yes. Most of the work is outside until the back wall is opened near the end, and that stage is screened off.
How long does a semi extension take?
10 to 16 weeks on site for a single-storey extension.
Who will build my extension?
Vetted building teams working under contract to us. Your contract is with S&K Property Investments and Improvement Ltd for the design and the build.
Do you handle building control in Castle Vale?
Yes. We apply to the council or a registered building control approver and hand over the completion certificate.
How much does a semi-detached rear extension cost in Castle Vale?
As a guide, £1,900–£3,100 per square metre including VAT for a standard specification. For example, 3 m wide × 4 m deep (12 m²): about £23,000–£37,000 at that rate. Your written price follows the survey.