Covering West Sussex
Our coverage across West Sussex includes Crawley, Worthing, Bognor Regis and Littlehampton.
Homes in the South East
Many South East homes are inter-war or post-war semis and detached houses with room for rear and side extensions, while historic town centres and villages bring conservation area and listed building controls.
What does a side return extension involve?
Side returns are small in area but heavy in detail: party walls, a glazed roof, and steelwork to take out the original back wall. We design the roof for light and drainage, agree the party wall process early, and keep the work tidy because access is often through the house.
- Glazed or solid roof with rooflights
- Drainage and new gully positions
- Underfloor heating ready screed if wanted
How much should I budget for a side return extension?
Indicative costs for side return extensions. London and the South East usually sit towards the top of each range.
| Side return extensions | Guide price incl. VAT |
|---|---|
| Standard specification | £3,350 to £3,700 per m² |
| Good specification | £3,700 to £4,150 per m² |
| High specification | £4,150 to £4,550 per m² |
What approvals does a side return extension need in England?
In England we deal with the council’s planning team for permission or a lawful development certificate, with building control (the council or a registered building control approver) for inspections, and with neighbours under the Party Wall etc. Act 1996 where it applies.
In England a single-storey rear extension can often go ahead under permitted development: up to 3 m deep on an attached house or 4 m on a detached one, no higher than 4 m, with eaves no higher than 3 m within 2 m of a boundary. Deeper extensions, up to 6 m or 8 m, need prior approval from the council first.
What can change the price or programme?
- Access is often through the house, so we plan deliveries and protect floors.
- Many terraces sit in conservation areas, where side extensions need planning permission.
What are the steps?
- Start with a conversation. A short call or the online form is enough for us to understand what you want to build.
- Free site visit. We measure up, look at access, drains and the structure, and talk through options and budget.
- Design and fixed price. You get drawings and a written price for the agreed specification before anything is ordered.
- We build it. Work follows an agreed programme, with inspections at each stage and a final sign-off.
Side return extensions: common questions
How much does a side return extension cost?
Usually about £3,350 to £4,550 per square metre including VAT, which works out at around £35,000 to £55,000 for a typical side return before the kitchen.
Is a glazed roof too hot in summer?
Modern solar-control glass and a mix of glazed and solid roof keep it comfortable. We advise on the balance during design.
How do I get a price for side return extensions in West Sussex?
Use the guide price tool for a ballpark figure, then book a visit for a fixed written price for the agreed specification.
Side return extensions near West Sussex
- Side return extensions in Crawley
- Side return extensions in Worthing
- Side return extensions in Bognor Regis
- Side return extensions in Littlehampton
- Side return extensions in Horsham
- Side return extensions in Haywards Heath
- Side return extensions in Chichester
- Side return extensions in Burgess Hill
- Side return extensions in East Grinstead
Learn more about side return extensions, or see every project we cover in West Sussex.

