Wraparound extensions across Chiswick
Our design and build teams take on wraparound extensions in Chiswick, from the first measured survey through planning and building control to the finished room.
- Guide price in ChiswickFrom £46,500 inc VAT
- PlanningUsually a householder application
- Build time14–20 weeks on site
- Postcode districtsSW13, SW14, W3, W4, W6

What should I budget for a wraparound extension in Chiswick?
For Chiswick we adjust our national guide rates by ×1.3, the factor we use for London. Figures include VAT; your written quote after the survey replaces them.
Typical rates in Chiswick: £2,600 to £4,810 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| Compact L-shape 18 m² | £46,500 – £56,500 | £53,500 – £68,000 | £67,500 – £87,000 |
| Medium L-shape 25 m² | £65,000 – £78,000 | £74,500 – £94,500 | £94,000 – £120,500 |
| Large L-shape 32 m² | £83,000 – £100,000 | £95,500 – £121,000 | £120,500 – £154,000 |
For a figure based on your own dimensions, use our guide-price tool.
Will the council need to approve it?
In England a wraparound extension is assessed as both a side and a rear extension, and the combination usually falls outside permitted development, so most need a householder planning application (£548 from 1 April 2026).
Homes in conservation areas, national parks, National Landscapes (formerly AONBs), the Broads and World Heritage Sites have tighter rules, so we always check the property's status and planning history before design starts.
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).
Extensions in and around Chiswick
Postcode districts we cover around Chiswick include SW13, SW14, W3, W4, W6, W12. We also work in nearby Acton (1 mile), Barnes (1 mile), Shepherds Bush (2 miles), Notting Hill (3 miles).
For homes towards Surrey, East Molesey is around 8 miles away. 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.
When a wraparound extension makes sense
- Terraced houses that want the largest ground floor possible
- Families who want kitchen, dining and living in one space
- Semi-detached houses with a side passage
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
It starts with a visit to your house to measure, check access and talk through ideas and budget.
Design and approvals
We produce the drawings and structural design, and manage the approvals so they are in place before work starts.
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
Our team builds the extension, keeps you updated weekly and finishes with building control sign-off.
Your questions about a wraparound extension in Chiswick
How long does a wraparound extension take to build in Chiswick?
On site, typically 14 to 20 weeks once approvals are in place. Before that, allow 8–16 weeks design and approvals.
Will my neighbours in Chiswick 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.
Do I need building regulations approval in Chiswick?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
How much does a wraparound extension cost?
Our guide range is about £2,600 to £4,810 per m² including VAT. A 25 m² standard-spec wraparound typically lands around £74,500 to £94,500 in Chiswick before design and council fees.
Will I need to move a drain?
Often. Side returns frequently contain a manhole or a shared drain. Building near or over a public sewer needs the water company’s consent in England and Wales, which we arrange.
Book a free site visit in Chiswick
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.