Side extensions in Hounslow
From the first sketch to final sign-off, we plan and build side extensions in Hounslow and the surrounding Greater London area.
- Guide price in HounslowFrom £28,500 inc VAT
- PlanningSingle storey can be permitted development
- Build time10–18 weeks on site
- Postcode districtsTW1, TW2, TW3, TW4, TW5
What should I budget for a side extension in Hounslow?
Labour and material costs vary across the UK, so for Hounslow we use our London factor (×1.3). The ranges include VAT and exclude design, structural and council fees.
Typical rates in Hounslow: £2,280 to £4,420 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 2.5 m × 5 m 12 m² | £28,500 – £34,500 | £31,500 – £41,500 | £40,500 – £53,500 |
| 3 m × 6 m 18 m² | £40,500 – £49,500 | £47,500 – £62,500 | £60,500 – £80,000 |
| 3 m × 8 m 24 m² | £54,500 – £66,000 | £63,500 – £83,000 | £81,000 – £106,500 |
Want a range for your exact size? The guide-price tool takes about a minute.
Working in Hounslow
Across TW1, TW2, TW3, TW4, TW5, TW7, we can visit, measure and advise. 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.
Planning and approvals in Hounslow
In England a single-storey side extension can be permitted development if it is no more than 4 m high and no wider than half the width of the original house. Two-storey side extensions, and any side extension on designated land such as a conservation area, need a householder planning application.
Before any drawing is finalised we check whether the house is listed, in a conservation area or subject to an Article 4 direction.
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).
Who a side extension suits
- Houses where the rear garden is small
- Homes needing a utility, study or ground-floor bedroom
- Detached and semi-detached houses with side land
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
We visit your Hounslow home, measure up, talk through what you want and check the planning position.
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
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
Who do I contract with for a side extension in Hounslow?
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.
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 extension take to build in Hounslow?
On site, typically 10 to 18 weeks once approvals are in place. Before that, allow 6–14 weeks design and approvals.
Can I build over my driveway?
Yes, if the foundations work and you keep any parking the council requires. Drains and services under drives are common, so we check before design.
Can I build a side extension without planning permission?
In England a single-storey side extension can be permitted development if it is no more than 4 m high and no wider than half the width of the original house. Two-storey side extensions, and any side extension on designated land such as a conservation area, need a planning application.
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.