Worthing, West Sussex
Single-storey rear extension in Worthing
Ground-floor space across the back of the house, usually for a kitchen, dining or family room. If you live in Worthing 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.
Worthing is covered from our West Sussex round, including BN11, BN12, BN13 and BN14. A depth of 3 to 4 metres keeps many single-storey rear extensions in Worthing 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 Worthing?
Guide prices for a single-storey rear extension in Worthing 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 |
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 Worthing?
The planning route for a single-storey rear extension in Worthing is set by England's householder rules and your council.
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 Worthing like to extend?
Worthing has a mix of Victorian terraces near the centre and larger Edwardian and inter-war houses further out. Clay soils across much of the South East mean deeper foundations near trees, which we plan for at the survey.
How a single-storey rear extension in Worthing 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.
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 Worthing
Close by, we work in Lancing, about 2.4 miles away, and Shoreham-by-Sea, about 4.6 miles away.
- Single-storey rear extension in Lancing
- Single-storey rear extension in Shoreham-by-Sea
- Single-storey rear extension in Rustington
- Single-storey rear extension in Portslade
- Single-storey rear extension in Littlehampton
Other work in Worthing:
FAQ
Single-storey rear extension questions in Worthing
What postcode areas do you cover around Worthing?
Including BN11, BN12, BN13 and BN14, and the surrounding West Sussex 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.
Can I stay in the house during the build?
Usually yes. The noisiest, dustiest stage, removing the back wall, is kept to the final weeks and screened off. Most families set up a temporary kitchen elsewhere in the house.
How long does a rear extension take to build in Worthing?
Most single-storey rear extensions take 10 to 16 weeks on site and two-storey extensions 16 to 26 weeks, after design and approvals.
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 planning permission for a rear extension in Worthing?
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.