Side return extensions in Ewell: design, approvals and build
If you live in Ewell and want more space without moving, a side return extension is one of the most practical ways to get it. We handle the drawings, approvals and the build.
- Guide price in EwellFrom £20,000 inc VAT
- PlanningOften permitted development; party wall notice usual
- Build time10–14 weeks on site
- Postcode districtsKT17, KT18, KT19

What is included
- Kitchen-ready shell or full finish
- Survey of the outrigger, boundary wall and drainage
- Removal of the side wall and new steelwork
- Party wall notice support (England and Wales)
What should I budget for a side return extension in Ewell?
Prices below are for Ewell, using the South East England factor of ×1.12. They are guide ranges including VAT for the build only, not a quote.
Typical rates in Ewell: £2,350 to £4,260 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 1.8 m × 4.5 m 8 m² | £20,000 – £24,000 | £21,500 – £27,000 | £26,500 – £34,500 |
| 2 m × 5.5 m 11 m² | £25,500 – £31,000 | £29,500 – £37,000 | £36,500 – £47,000 |
| 2.2 m × 7 m 15 m² | £35,000 – £42,500 | £40,000 – £50,500 | £50,000 – £64,000 |
Want a range for your exact size? The guide-price tool takes about a minute.
Will the council need to approve it?
In England a single-storey side return infill is often permitted development if it stays within the height limits and is no wider than half the width of the original house. Conservation areas, listed buildings and flats always need an application, and the boundary wall usually brings in the Party Wall Act.
Homes in conservation areas, national parks, National Landscapes (formerly AONBs), the Broads and World Heritage Sites have tighter rules, so we always check the property's status and planning history before design starts.
If the work involves a shared wall, building on the boundary, or digging foundations within 3 m (sometimes 6 m) of a neighbour's building, the Party Wall etc. Act 1996 applies and notice must be served before work starts: two months for work to a party wall, one month for new walls on the boundary and for excavations.
Building over or within 3 m of a public sewer needs the water company's consent, usually through a build-over agreement, before the foundations go in.
Applications are decided by the local planning authority (your district, borough or unitary council).
Covering Ewell
Postcode districts we cover around Ewell include KT17, KT18, KT19. We also work in nearby Epsom (2 miles), Banstead (3 miles), Leatherhead (5 miles), Esher (5 miles).
In the South East, plenty of houses have already been extended once, which makes checking the remaining permitted development allowance an important early step.
How the project works
Site visits are free and there is no obligation. Where drawings are needed, the design stage is priced in writing before it starts.
Free site visit
First, a site visit: we look at the house, garden, access and drains and listen to what you need.
Design and approvals
Once the layout is agreed, we deal with the council: planning permission or written confirmation that none is needed, plus building control.
Fixed written price
We confirm the build price in writing, based on the approved drawings and the finishes you have chosen.
Build and sign-off
The build is managed from start to finish, inspected at each stage and signed off on completion.
Your questions about a side return extension in Ewell
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Ewell, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
Do you cover all of Ewell?
Yes. We cover Ewell and the surrounding parts of Surrey. Site visits are free and there is no obligation.
How long does a side return extension take to build in Ewell?
On site, typically 10 to 14 weeks once approvals are in place. Before that, allow 6–12 weeks design and approvals.
How much does a side return extension cost?
Our guide range is about £2,350 to £4,260 per m² including VAT, so a typical 2 m × 5.5 m infill lands around £29,500 to £37,000 at standard spec in Ewell, more in London.
Do side return extensions need planning permission?
In England many single-storey side returns fit within permitted development if they stay within the height limits and are no wider than half the width of the original house. Conservation areas, listed buildings and flats need an application. Other UK nations have their own rules, which we check.
Book a free site visit in Ewell
We will measure up, check the planning position and give you honest guide figures.
- Free, no-obligation site visit
- Planning route checked before you spend on drawings
- Written price once the design is agreed
- Building control sign-off at the end
Prefer to talk? Call 0800 088 6341 or .
Book a free site visit
Tell us a little about the project and we will arrange a time.