Selsey, West Sussex
Single-storey rear extension in Selsey
For homes in Selsey, a single-storey rear extension is often the simplest way to gain space without moving. Ground-floor space across the back of the house, usually for a kitchen, dining or family room. We take it from survey to completion certificate.
Selsey is covered from our West Sussex round, including PO20. On inter-war semis and 1960s estates like those around Selsey, 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 Selsey?
Guide prices for a single-storey rear extension in Selsey start from our South East England rate of £2,130–£3,470 per square metre, including VAT. South East prices run above our West Midlands baseline, mainly on labour rates and clay-soil foundations.
| Size | Guide price inc VAT |
|---|---|
| 3 m wide × 4 m deep (12 m²) | £25,500–£41,500 |
| 4 m wide × 5 m deep (20 m²) | £42,500–£69,500 |
| 4 m wide × 6 m deep (24 m²) | £51,000–£83,500 |
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 Selsey?
Here is how the rules in England apply to a single-storey rear extension in Selsey.
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.
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. 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 Selsey like to extend?
Around Selsey the housing ranges from inter-war semis to 1960s and 1970s estates with good-sized gardens. Many of the newer estates had permitted development rights removed by condition, so we check the planning history before anything is drawn.
How a single-storey rear extension in Selsey 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.
Design and guide price
Two or three layout options with a guide price for each, so you choose the design knowing what it costs.
Approvals
Permitted development check, prior approval or planning application, then Building Regulations drawings and structural calculations, plus party wall notices where they apply.
Build and sign-off
We build to the approved drawings with regular updates, then hand over the building control completion certificate and any guarantees from suppliers.
Single-storey rear extensions near Selsey
We also build single-storey rear extensions in nearby Bognor Regis (5.8 miles) and Chichester (7.0 miles).
- Single-storey rear extension in Bognor Regis
- Single-storey rear extension in Chichester
- Single-storey rear extension in Hayling Island
- Single-storey rear extension in South Hayling
- Single-storey rear extension in Barnham
Other work in Selsey:
FAQ
Single-storey rear extension questions in Selsey
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 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 structural engineer?
Yes for the beam over the new opening and usually for the foundations. Their calculations go to building control with the drawings.
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 much does a single-storey rear extension cost in Selsey?
As a guide, £2,130–£3,470 per square metre including VAT for a standard specification. For example, 3 m wide × 4 m deep (12 m²): about £25,500–£41,500 at that rate. Your written price follows the survey.
What postcode areas do you cover around Selsey?
Including PO20, and the surrounding West Sussex area.