Smethwick, West Midlands
Semi-detached rear extension in Smethwick
Single or two-storey extensions for semi-detached houses, with side access and one party wall. If you live in Smethwick and want to know what a semi-detached rear extension would cost and whether it needs planning, start with the online guide price or a free site visit.
We cover Smethwick (B66, B67 and B68) as part of our West Midlands work. Semi-detached houses are common across the West Midlands, and their side access makes rear extensions quicker to build.
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 Smethwick?
A semi-detached rear extension in Smethwick is priced at £1,900–£3,100 per square metre including VAT as a guide, before kitchen fit-out and fees. 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 |
Ground conditions, glazing, the roof and how far the house is opened up move the final figure within the range.
Do you need planning permission for a semi-detached rear extension in Smethwick?
The planning route for a semi-detached rear extension in Smethwick is set by England's householder rules and your council.
English permitted development (Class A) allows a single-storey rear extension of 3 metres on a terraced or semi-detached house and 4 metres on a detached one, measured from the original house, with a maximum height of 4 metres and eaves of no more than 3 metres 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.
If 3 or 4 metres is not enough, England's prior approval route allows 6 metres on a terraced or semi-detached house and 8 metres on a detached house for a single-storey rear extension. Neighbours are consulted, the council decides within 42 days, and the fee is £249, rising to £310 from 8 December 2026.
Conservation areas, National Parks, National Landscapes and the Broads restrict permitted development, and listed buildings always need listed building consent. Before any drawing we look up the property's history with the council, because earlier extensions and removed rights change the answer.
What are homes in Smethwick like to extend?
Red-brick terraces and 1930s semis make up much of Smethwick. 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 Smethwick comes together
Free site visit
We measure the house and garden, look at the back wall, drainage and boundaries, and talk through what you want from the space.
Design and guide price
Two or three layout options with a guide price for each, so you choose the design knowing what it costs.
Planning and regulations
We take the design through the right planning route, then produce the construction drawings and engineer's calculations for building control.
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 Smethwick
We also build rear extensions for semi-detached houses in nearby West Bromwich (2.1 miles) and Oldbury (2.1 miles).
- Semi-detached rear extension in West Bromwich
- Semi-detached rear extension in Oldbury
- Semi-detached rear extension in Hockley
- Semi-detached rear extension in Birmingham
- Semi-detached rear extension in Aston
Other work in Smethwick:
FAQ
Semi-detached rear extension questions in Smethwick
Can you match the brick or stone on my Smethwick house?
We source the closest match and show you samples before ordering; reclaimed materials are often the best match on older houses.
What postcode areas do you cover around Smethwick?
Including B66, B67 and B68, and the surrounding West Midlands area.
Single or two-storey on a semi?
Two-storey if you need bedrooms, single-storey if you need a bigger kitchen. Planning risk is lower for single-storey.
Do you handle building control in Smethwick?
Yes. We apply to the council or a registered building control approver and hand over the completion certificate.
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.
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.