Henlow, Bedfordshire
Single-storey rear extension in Henlow
We plan and build single-storey rear extensions for homeowners in Henlow. 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.
Henlow is covered from our Bedfordshire round, including SG16. A depth of 3 to 4 metres keeps many single-storey rear extensions in Henlow within permitted development, subject to the house's planning history.
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 Henlow?
A single-storey rear extension in Henlow is priced at £2,010–£3,290 per square metre including VAT as a guide, before kitchen fit-out and fees. 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 |
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 single-storey rear extension in Henlow?
Whether your single-storey rear extension in Henlow needs a planning application depends on its size, your house and any local restrictions.
Under England's householder permitted development rules you can usually add 3 metres at the back of an attached house, or 4 metres on a detached house, without a planning application, as long as the extension stays under 4 metres high and its eaves stay under 3 metres where it 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 Henlow like to extend?
Post-war semis and newer estates are typical of Henlow, and many have room for a full-width extension. Shrinkable clay is common in the East of England, so foundations near trees and hedges are designed to NHBC-style depth guidance.
How a single-storey rear extension in Henlow 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.
Single-storey rear extensions near Henlow
From Henlow, the nearest places we also cover are Biggleswade (4.0 miles) and Letchworth Garden City (4.3 miles).
- Single-storey rear extension in Biggleswade
- Single-storey rear extension in Letchworth Garden City
- Single-storey rear extension in Baldock
- Single-storey rear extension in Hitchin
- Single-storey rear extension in Sandy
Other work in Henlow:
FAQ
Single-storey rear extension questions in Henlow
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.
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.
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 much does a single-storey rear extension cost in Henlow?
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.
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.
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.