Side return extensions in Hounslow: design, approvals and build
Thinking about a side return extension for your Hounslow home? Start with a free site visit: we measure up, check what the council will allow and give you honest guide figures on the day.
- Guide price in HounslowFrom £23,000 inc VAT
- PlanningOften permitted development; party wall notice usual
- Build time10–14 weeks on site
- Postcode districtsTW1, TW2, TW3, TW4, TW5
Planning and approvals in Hounslow
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.
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).
Side return extension prices in Hounslow
These guide figures apply our London adjustment (×1.3) to national rates. They include VAT at 20% and cover the build itself; design and council fees are listed separately.
Typical rates in Hounslow: £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.
Who a side return extension suits
- Narrow galley kitchens
- Homes where the garden is too small to lose much depth
- Victorian and Edwardian terraces with a rear outrigger
Light is the design problem. A side return can make the middle of the house darker if the roof is solid, so we model the daylight and usually recommend a glazed slope or a run of rooflights along the boundary edge.
Local to Hounslow
Postcode districts we cover around Hounslow include TW1, TW2, TW3, TW4, TW5, TW7. The same team covers Isleworth (1 mile), Heston (1 mile), Richmond (2 miles), Hanworth (3 miles), all within easy reach.
In London, space is at a premium and gardens are often short, so side returns, wraparounds and carefully planned rear extensions tend to make the most of every metre.
What happens next
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
The build is managed from start to finish, inspected at each stage and signed off on completion.
Common questions in Hounslow
Will my neighbours in Hounslow be involved?
If a planning application or prior approval is needed, the council notifies neighbours. If the work is on or near a shared boundary, party wall notices may also be needed.
How long does a side return extension take to build in Hounslow?
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 Hounslow?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
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.
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.
Book a free site visit in Hounslow
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.