Knowle, West Midlands
Single-storey rear extension in Knowle
Thinking about a single-storey rear extension in Knowle? Ground-floor space across the back of the house, usually for a kitchen, dining or family room. Our team handles the drawings, the planning route and the build, and your contract is with one company throughout.
We cover Knowle (B40) as part of our West Midlands work. A single-storey rear extension in Knowle is mostly built from the garden side, so the house stays usable for most of the job.
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 single-storey rear extension cost in Knowle?
A single-storey rear extension in Knowle 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 |
Your written price follows a measured survey and an agreed design, so it reflects your house, not an average.
Do you need planning permission for a single-storey rear extension in Knowle?
Planning for a single-storey rear extension in Knowle follows the English householder rules.
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.
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. We check your house's planning history and any conservation area before drawing, so the route is clear before you spend on plans.
What are homes in Knowle like to extend?
Red-brick terraces and 1930s semis make up much of Knowle. Many already have a small kitchen lean-to at the back, which a new rear extension usually replaces rather than adds to.
How a single-storey rear extension in Knowle comes together
Look round and measure
A free visit to see the back of the house, measure it, check the drains and boundaries and hear what you need.
Drawings and budget
Floor plans and elevations for the options, each with a guide price.
Paperwork handled
Planning, prior approval or permitted development, Building Regulations approval, structural design and party wall notices are all handled by us.
Written price, then build
Once the design and approvals are in place, you get a fixed written price and programme, and we build through to sign-off.
Single-storey rear extensions near Knowle
Neighbouring places we cover include Solihull (2.9 miles) and Shirley (4.1 miles).
- Single-storey rear extension in Solihull
- Single-storey rear extension in Shirley
- Single-storey rear extension in Acocks Green
- Single-storey rear extension in Chelmsley Wood
- Single-storey rear extension in Kenilworth
Other work in Knowle:
FAQ
Single-storey rear extension questions in Knowle
Do I need a party wall agreement?
In England, usually yes if the extension is on or near a shared boundary or the foundations are close to a neighbour's building. We serve the notices.
Can you match the brick or stone on my Knowle house?
We source the closest match and show you samples before ordering; reclaimed materials are often the best match on older houses.
Can I stay in the house during the build?
Usually yes. The noisiest, dustiest stage, removing the back wall, is kept to the final weeks and screened off. Most families set up a temporary kitchen elsewhere in the house.
What postcode areas do you cover around Knowle?
Including B40, and the surrounding West Midlands area.
Do I need planning permission for a rear extension in Knowle?
Often not for a single-storey rear extension of up to 3 metres (4 metres on a detached house) under permitted development, or up to 6 or 8 metres with prior approval, unless the house is in a conservation area or its rights have been removed.
Will I need a structural engineer?
Yes for the beam over the new opening and usually the foundations; we arrange them and their calculations go to building control.