Porch extensions for homes in Isleworth
From the first sketch to final sign-off, we plan and build porch extensions in Isleworth and the surrounding Greater London area.
- Guide price in IsleworthFrom £5,200 inc VAT
- PlanningUsually permitted development under 3 m²
- Build time2–4 weeks on site
- Postcode districtsTW1, TW3, TW4, TW5, TW7
Working in Isleworth
Site visits are available across Isleworth (TW1, TW3, TW4, TW5, TW7, TW8). The same team covers Hounslow (1 mile), Heston (2 miles), Richmond (2 miles), Southall (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.
Included in a typical project
- Front door, glazing and electrics
- Brick, render or oak frame walls
- Foundations and drainage for rainwater
- Tiled, slate or flat roof
Proportion matters on a porch more than on any other extension, because it is at the front. We match the roof pitch and brick and keep the front door in proportion with the house windows.
What should I budget for a porch 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.
| Option | What it covers | Guide price |
|---|---|---|
| Essential | Small brick or glazed porch, up to 3 m² | £5,200 – £8,450 |
| Standard | Brick porch with tiled roof and composite door | £7,800 – £12,350 |
| Premium | Larger porch with WC or oak frame and premium glazing | £11,700 – £19,500 |
Try the guide-price tool to see a range for your own size and finish.
Planning and approvals in Isleworth
In England a porch is usually permitted development if its ground floor area is no more than 3 m² measured externally, no part is over 3 m high, and no part is within 2 m of a boundary next to a road.
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.
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).
How the project works
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
It starts with a visit to your house to measure, check access and talk through ideas and budget.
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
The price is fixed in writing once the design is settled, with a clear programme and payment stages.
Build and sign-off
Work is carried out to the agreed programme, inspected by building control and signed off at the end.
Porch extension questions answered
Will my neighbours in Isleworth 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.
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.
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 much does a porch cost?
Our guide range is about £5,200 to £19,500 including VAT, depending on size, materials and whether it includes a WC.
Do I need planning permission for a porch?
In England a porch is usually permitted development if its ground floor area is no more than 3 m² (measured externally), no part is higher than 3 m, and no part is within 2 m of a boundary next to a highway. Other nations have similar but separate rules.
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.