Timber frame extensions for homes in Isleworth
Thinking about a timber frame extension for your Isleworth 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 IsleworthFrom £27,000 inc VAT
- PlanningOften permitted development (3–4 m), or prior approval up to 6–8 m
- Build time8–14 weeks on site
- Postcode districtsTW1, TW3, TW4, TW5, TW7
Who a timber frame extension suits
- Sites where weight or speed matters
- Homeowners who want strong energy performance
- Contemporary designs with timber or board cladding
Moisture is the enemy of any timber building. We design ventilated cladding cavities, breather membranes and a proper damp-proof course height, and keep the frame dry during construction.
What should I budget for a timber frame extension in Isleworth?
Prices below are for Isleworth, using the London factor of ×1.3. They are guide ranges including VAT for the build only, not a quote.
Typical rates in Isleworth: £2,280 to £4,420 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 3 m × 4 m 12 m² | £27,000 – £33,000 | £31,500 – £41,500 | £40,500 – £53,500 |
| 4 m × 5 m 20 m² | £45,500 – £55,000 | £53,000 – £69,000 | £67,500 – £88,500 |
| 5 m × 6 m 30 m² | £68,000 – £82,000 | £79,500 – £103,500 | £101,000 – £133,000 |
For a figure based on your own dimensions, use our guide-price tool.
Working in Isleworth
We cover Isleworth and the postcode districts TW1, TW3, TW4, TW5, TW7, TW8. Nearby, we also take on projects in Hounslow (1 mile), Heston (2 miles), Richmond (2 miles), Southall (3 miles).
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.
Planning rules that apply in Isleworth
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.
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.
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).
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
First, a site visit: we look at the house, garden, access and drains and listen to what you need.
Design and approvals
Drawings are prepared and agreed with you, then submitted for the right planning route and building regulations approval.
Fixed written price
With the design and specification agreed, you get a fixed written price and a start date.
Build and sign-off
Work is carried out to the agreed programme, inspected by building control and signed off at the end.
Common questions in Isleworth
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 timber frame extension take to build in Isleworth?
On site, typically 8 to 14 weeks once approvals are in place. Before that, allow 4–12 weeks design and approvals.
Do I need building regulations approval in Isleworth?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Is timber frame cheaper than brick?
It is similar overall. The frame can save time on site, but the cladding choice has a big effect on cost. Our guide range is about £2,280 to £4,420 per m² including VAT.
Does a timber frame extension need planning permission?
The same planning rules apply as for any extension. If the cladding looks different from the house, permitted development’s matching-materials condition may mean an application is needed.
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.