Single-storey rear extensions across Southall
We design and build single-storey extensions for houses in Southall, with a written price once the survey and design are done and one point of contact throughout.
- Guide price in SouthallFrom £27,000 inc VAT
- PlanningOften permitted development (3–4 m), or prior approval up to 6–8 m
- Build time10–16 weeks on site
- Postcode districtsTW5, UB1, UB2, UB3, UB4
Will the council need to approve it?
In England a single-storey rear extension can usually go up to 3 m beyond the original rear wall of a semi-detached or terraced house, or 4 m on a detached house, without a planning application, provided it is no more than 4 m high, keeps eaves to 3 m within 2 m of a boundary and, with other buildings, covers no more than half the land around the original house. The larger home extension prior approval scheme raises those depths to 6 m and 8 m, with neighbours notified and a 42-day decision.
In a conservation area, national park, National Landscape, the Broads or a World Heritage Site the permitted development limits are tighter (no side or two-storey extensions without an application). Listed homes need listed building consent, and if permitted development rights have been removed, any extension needs an application.
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.
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.
Applications are decided by the local planning authority (your district, borough or unitary council).
Covering Southall
Postcode districts we cover around Southall include TW5, UB1, UB2, UB3, UB4, W7. The same team covers Greenford (2 miles), Heston (2 miles), Hayes (Hillingdon) (2 miles), Isleworth (3 miles), all within easy reach.
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.
Is a single-storey extension right for your house?
- Homeowners who want open-plan living onto the garden
- Semi-detached and detached houses with a usable rear garden
- Terraced houses that want a deeper kitchen across the full width
How much does a single-storey extension cost in Southall?
For Southall we adjust our national guide rates by ×1.3, the factor we use for London. Figures include VAT; your written quote after the survey replaces them.
Typical rates in Southall: £2,280 to £4,420 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 3 m × 4 m 12 m² | £27,000 – £32,000 | £31,500 – £41,000 | £40,500 – £53,500 |
| 4 m × 5 m 20 m² | £45,500 – £53,500 | £53,000 – £68,000 | £67,500 – £88,500 |
| 5 m × 6 m 30 m² | £68,000 – £80,000 | £79,500 – £101,500 | £101,000 – £133,000 |
Try the guide-price tool to see a range for your own size and finish.
Our process, step by step
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 draw the design, agree it with you and handle planning or permitted development checks and building regulations.
Fixed written price
You receive a written, itemised price and programme. Nothing starts until you are happy with it.
Build and sign-off
Our team builds the extension, keeps you updated weekly and finishes with building control sign-off.
Single-storey extension questions answered
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Southall, 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 I need building regulations approval in Southall?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Who do I contract with for a single-storey extension in Southall?
Your contract is with S&K Property Investments and Improvement Ltd, which designs and manages the project and the build teams who carry it out.
Flat roof or pitched roof?
Flat roofs give more headroom inside and suit lanterns and rooflights; pitched roofs can blend better with older houses. Both meet building regulations when built properly. See our flat roof and pitched roof pages for the details.
How much does a single-storey extension cost per square metre?
Our guide range is about £2,280 to £4,420 per m² including VAT, depending on specification. A standard-spec 4 m × 5 m room usually lands at £53,000 to £68,000 in Southall, plus design and council fees.
Book a free site visit in Southall
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.