Side return extensions for homes in Coulsdon
If you live in Coulsdon 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 CoulsdonFrom £23,000 inc VAT
- PlanningOften permitted development; party wall notice usual
- Build time10–14 weeks on site
- Postcode districtsCR5, CR8

Guide prices for Coulsdon
Labour and material costs vary across the UK, so for Coulsdon we use our London factor (×1.3). The ranges include VAT and exclude design, structural and council fees.
Typical rates in Coulsdon: £2,730 to £4,940 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 1.8 m × 4.5 m 8 m² | £23,000 – £28,000 | £24,500 – £31,500 | £31,000 – £40,000 |
| 2 m × 5.5 m 11 m² | £30,000 – £36,000 | £34,000 – £43,000 | £42,500 – £54,500 |
| 2.2 m × 7 m 15 m² | £40,500 – £49,000 | £46,500 – £58,500 | £58,500 – £74,500 |
Try the guide-price tool to see a range for your own size and finish.
Covering Coulsdon
Our survey diary covers Coulsdon, including CR5, CR8. Neighbouring towns we cover include Purley (2 miles), Wallington (3 miles), Sutton (3 miles), Carshalton (4 miles).
For homes towards Surrey, Banstead is around 3 miles away. Across London, terraced houses with narrow side returns and tight access are the norm, which shapes everything from party wall notices to how materials reach the back garden.
When a side return extension makes sense
- Narrow galley kitchens
- Victorian and Edwardian terraces with a rear outrigger
- Homes where the garden is too small to lose much depth
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.
Before any drawing is finalised we check whether the house is listed, in a conservation area or subject to an Article 4 direction.
Building regulations approval is separate from planning. In England you can use the council's building control team or a registered building control approver; a full plans application gets the drawings checked before work starts, and the inspector signs the work off with a completion certificate.
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).
From first visit to completion
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
A designer visits, takes measurements and photos, and discusses layouts, budget and timing with you.
Design and approvals
We produce the drawings and structural design, and manage the approvals so they are in place before work starts.
Fixed written price
The price is fixed in writing once the design is settled, with a clear programme and payment stages.
Build and sign-off
The build is managed from start to finish, inspected at each stage and signed off on completion.
Side return extension questions answered
Do you cover all of Coulsdon?
Yes. We cover Coulsdon and the surrounding parts of Greater London. Site visits are free and there is no obligation.
How long does a side return extension take to build in Coulsdon?
On site, typically 10 to 14 weeks once approvals are in place. Before that, allow 6–12 weeks design and approvals.
Do I need building regulations approval in Coulsdon?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Can I combine a side return with a rear extension?
Yes. That combination is a wraparound extension, which adds the most space to a terraced house.
Will the kitchen be darker?
Not if the roof is designed well. A glazed roof or a line of rooflights along the boundary usually makes the room brighter than before.
Book a free site visit in Coulsdon
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.