Covering Horsham
We work in Horsham (RH12) and the places around it, including Crawley, Horley and Haywards Heath.
Homes in the South East
Housing across the South East mixes inter-war semis, post-war estates and older cottages in villages and market towns, so rear and side extensions, hip-to-gable lofts and garage conversions all come up regularly.
What do you get with a side return extension?
A side return extension builds over the narrow passage that runs beside the back of many Victorian and Edwardian terraced houses, widening the kitchen or dining room by a metre or two. It is usually combined with a glazed or part-glazed roof so the deeper room still gets daylight.
- Party wall notices and surveyor liaison
- Glazed or solid roof with rooflights
- Drainage and new gully positions
What will a side return extension cost?
Guide prices for side return extensions, including VAT where it applies. Your fixed price is confirmed in writing after the survey.
| 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 |
Planning and building rules in Horsham
English projects need planning clearance from the local council, building regulations sign-off from building control, and party wall notices where the work is on or near a shared boundary. We prepare and manage all three.
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.
What can affect a side return extension?
- Most side returns touch a shared boundary, so the Party Wall etc. Act 1996 usually applies in England and Wales.
- Many terraces sit in conservation areas, where side extensions need planning permission.
From first call to completion
- Start with a conversation. A short call or the online form is enough for us to understand what you want to build.
- Survey at your house. We look at the existing structure, services and access, and agree what the design needs to achieve.
- Price and paperwork. The design is priced line by line, and we submit the planning and building control applications.
- Build and hand over. Our teams build to the programme, building control inspects, and you get the completion paperwork at the end.
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.
Does a side return need planning permission?
In England it can be permitted development if it is single storey, no higher than 4 m and no wider than half the original house. Conservation areas are the main exception.
Can you visit a house in Horsham to quote?
Yes. After a short call we arrange a site visit to measure up and agree what the design needs to do, then send a written price.
Side return extensions near Horsham
- Side return extensions in Crawley
- Side return extensions in Horley
- Side return extensions in Haywards Heath
- Side return extensions in Burgess Hill
Learn more about side return extensions, or see every project we cover in Horsham.

