Kempston, Bedfordshire
Single-storey rear extension in Kempston
We plan and build single-storey rear extensions for homeowners in Kempston. Ground-floor space across the back of the house, usually for a kitchen, dining or family room. Start with a free site visit, then a written price once the design is agreed.
Kempston sits in Bedfordshire, with postcode districts including MK42. A single-storey rear extension in Kempston 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 Kempston?
In Kempston, our guide for a single-storey rear extension is £2,010–£3,290 per square metre including VAT for a standard specification. East of England prices run slightly above our West Midlands baseline; clay soils near trees are the main foundation variable.
| Size | Guide price inc VAT |
|---|---|
| 3 m wide × 4 m deep (12 m²) | £24,000–£39,500 |
| 4 m wide × 5 m deep (20 m²) | £40,500–£65,500 |
| 4 m wide × 6 m deep (24 m²) | £48,500–£79,000 |
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 Kempston?
Here is how the rules in England apply to a single-storey rear extension in Kempston.
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.
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. 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 Kempston like to extend?
Kempston mixes Victorian terraces with 1930s semis, so both side returns and full-width kitchen extensions suit houses here.
How a single-storey rear extension in Kempston 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.
Drawings and budget
Floor plans and elevations for the options, each with a guide price.
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.
Single-storey rear extensions near Kempston
Close by, we work in Kempston Hardwick, about 1.8 miles away, and Bedford, about 1.9 miles away.
- Single-storey rear extension in Kempston Hardwick
- Single-storey rear extension in Bedford
- Single-storey rear extension in Ampthill
- Single-storey rear extension in Flitwick
- Single-storey rear extension in Sandy
Other work in Kempston:
FAQ
Single-storey rear extension questions in Kempston
How much does a single-storey rear extension cost in Kempston?
As a guide, £2,010–£3,290 per square metre including VAT for a standard specification. For example, 3 m wide × 4 m deep (12 m²): about £24,000–£39,500 at that rate. Your written price follows the survey.
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.
Do I need a structural engineer?
Yes for the beam over the new opening and usually for the foundations. Their calculations go to building control with the drawings.
How long does a rear extension take to build in Kempston?
Most single-storey rear extensions take 10 to 16 weeks on site and two-storey extensions 16 to 26 weeks, after design and approvals.
What postcode areas do you cover around Kempston?
Including MK42, and the surrounding Bedfordshire area.
Can I get a price without a visit?
Our online guide-price tool gives a range in a couple of minutes. A written price needs a survey.