Bungalow extensions for homes in Isleworth
We design and build bungalow extensions for houses in Isleworth, with a written price once the survey and design are done and one point of contact throughout.
- Guide price in IsleworthFrom £34,000 inc VAT
- PlanningSingle storey often permitted development
- Build time10–18 weeks on site
- Postcode districtsTW1, TW3, TW4, TW5, TW7
Is a bungalow extension right for your house?
- Homeowners planning for later life
- Families wanting more space on one floor
- Bungalows on larger plots
Bungalow roofs are often hipped, which makes tying in an extension roof a careful job. We draw the roof junction early because it drives both the look and the cost.
Will the council need to approve it?
In England a single-storey extension to a bungalow follows the normal permitted development limits (3 m or 4 m, or 6 m and 8 m through prior approval). Adding a first floor always needs planning permission.
The planning position for a specific Isleworth address depends on its history and any designations, which is why we check it at the first visit.
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 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.
Applications are decided by the local planning authority (your district, borough or unitary council).
Covering Isleworth
Our survey diary covers Isleworth, including TW1, TW3, TW4, TW5, TW7, TW8. Neighbouring towns we cover include Hounslow (1 mile), Heston (2 miles), Richmond (2 miles), Southall (3 miles).
Just over the Surrey border, East Molesey is about 5 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.
What should I budget for a bungalow extension in Isleworth?
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 Isleworth: £2,280 to £4,420 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 3 m × 5 m 15 m² | £34,000 – £41,000 | £39,500 – £52,000 | £50,500 – £66,500 |
| 4 m × 6 m 24 m² | £54,500 – £66,000 | £63,500 – £83,000 | £81,000 – £106,500 |
| L-shape 35 m² | £79,500 – £96,000 | £93,000 – £121,000 | £118,000 – £155,000 |
Try the guide-price tool to see a range for your own size and finish.
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
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
We build it with one project manager, book the building control inspections and hand over the completion certificate.
Bungalow extension questions answered
Do you cover all of Isleworth?
Yes. We cover Isleworth and the surrounding parts of Greater London. Site visits are free and there is no obligation.
How long does a bungalow extension take to build in Isleworth?
On site, typically 10 to 18 weeks once approvals are in place. Before that, allow 6–14 weeks design and approvals.
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Isleworth, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
Is it better to extend sideways or upwards?
Sideways and rearwards is usually simpler, cheaper and keeps single-level living. Upwards saves garden but means stairs, more structure and planning permission.
Can I extend a bungalow without planning permission?
In England a single-storey rear extension to a bungalow follows the same permitted development limits as a house: 3 m or 4 m, or up to 6 m or 8 m through prior approval. Adding a storey always needs planning permission.
Book a free site visit in Isleworth
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.