Stevenage, Hertfordshire
Single-storey rear extension in Stevenage
We plan and build single-storey rear extensions for homeowners in Stevenage. 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.
Stevenage is covered from our Hertfordshire round, including SG1 and SG2. On post-war semis and newer estates like those around Stevenage, a single-storey rear extension is usually the simplest way to fix a small back kitchen without touching the bedrooms.
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 Stevenage?
In Stevenage, 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 |
These are guide ranges; the written quote after the survey is the figure that counts.
Do you need planning permission for a single-storey rear extension in Stevenage?
Planning for a single-storey rear extension in Stevenage follows the English householder rules.
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.
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. 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 Stevenage like to extend?
Post-war semis and newer estates are typical of Stevenage, 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 Stevenage 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.
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.
Single-storey rear extensions near Stevenage
Neighbouring places we cover include Codicote (3.9 miles) and Hitchin (4.8 miles).
- Single-storey rear extension in Codicote
- Single-storey rear extension in Hitchin
- Single-storey rear extension in Letchworth Garden City
- Single-storey rear extension in Baldock
- Single-storey rear extension in Welwyn Garden City
Other work in Stevenage:
FAQ
Single-storey rear extension questions in Stevenage
How much does a single-storey rear extension cost in Stevenage?
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 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.
How deep can a single-storey rear extension be without planning?
In England, 3 metres on an attached house and 4 metres on a detached house under permitted development, or up to 6 and 8 metres with prior approval. Wales allows 4 metres; Scotland and Northern Ireland have their own limits.
Is the site visit in Stevenage free?
Yes. We visit, measure up and talk through the options with no cost and no obligation.
Do you handle building control in Stevenage?
Yes. We apply to the council or a registered building control approver and hand over the completion certificate.
Do I need planning permission for a rear extension in Stevenage?
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.