Billericay, Essex
Single-storey rear extension in Billericay
Ground-floor space across the back of the house, usually for a kitchen, dining or family room. If you live in Billericay and want to know what a single-storey rear extension would cost and whether it needs planning, start with the online guide price or a free site visit.
Billericay is covered from our Essex round, including CM12. A depth of 3 to 4 metres keeps many single-storey rear extensions in Billericay 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 Billericay?
A single-storey rear extension in Billericay 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 Billericay?
Planning for a single-storey rear extension in Billericay follows the English householder rules.
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 Billericay like to extend?
Post-war semis and newer estates are typical of Billericay, 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 Billericay 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.
Options and costs
We draw layout options and price each one, so the budget shapes the design rather than surprising you later.
Paperwork handled
Planning, prior approval or permitted development, Building Regulations approval, structural design and party wall notices are all handled by us.
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 Billericay
We also build single-storey rear extensions in nearby Basildon (4.5 miles) and Wickford (4.6 miles).
- Single-storey rear extension in Basildon
- Single-storey rear extension in Wickford
- Single-storey rear extension in Brentwood
- Single-storey rear extension in Pitsea
- Single-storey rear extension in Stanford-le-Hope
Other work in Billericay:
FAQ
Single-storey rear extension questions in Billericay
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 you handle building control in Billericay?
Yes. We apply to the council or a registered building control approver and hand over the completion certificate.
Does it add value to the house?
Nationwide's October 2025 house price research found that a 10% increase in floor area is linked to about 5% higher value on average. It is a guide, not a promise; local agents can tell you what extended homes on your street sell for.
How long does a rear extension take to build in Billericay?
Most single-storey rear extensions take 10 to 16 weeks on site and two-storey extensions 16 to 26 weeks, after design and approvals.
Do I need planning permission for a rear extension in Billericay?
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.
Is the site visit in Billericay free?
Yes. We visit, measure up and talk through the options with no cost and no obligation.