Conservatory replacement extensions across Chiswick
From the first sketch to final sign-off, we plan and build conservatory replacements in Chiswick and the surrounding Greater London area.
- Guide price in ChiswickFrom £26,000 inc VAT
- PlanningOften permitted development (3–4 m), or prior approval up to 6–8 m
- Build time8–14 weeks on site
- Postcode districtsSW13, SW14, W3, W4, W6

Will the council need to approve it?
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 Chiswick 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.
Applications are decided by the local planning authority (your district, borough or unitary council).
What should I budget for a conservatory replacement in Chiswick?
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 Chiswick: £2,400 to £4,550 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 3 m × 3.3 m 10 m² | £26,000 – £31,000 | £27,500 – £36,000 | £35,500 – £45,500 |
| 3.5 m × 4 m 14 m² | £33,500 – £40,500 | £39,000 – £50,500 | £50,000 – £64,000 |
| 4 m × 5 m 20 m² | £48,000 – £57,500 | £55,500 – £71,500 | £71,500 – £91,000 |
Includes removal of the old conservatory. Reusing existing foundations is only possible after investigation.
Want a range for your exact size? The guide-price tool takes about a minute.
Included in a typical project
- New or upgraded foundations
- Removal and disposal of the old conservatory
- Glazing and doors to suit the new room
- Insulated walls and roof to current regulations
- Trial holes to check the existing foundations
- Opening widened into the house if wanted
A replacement is a chance to rethink the shape. Many conservatories are oddly proportioned; for a similar cost the new room can often be squarer, wider or better connected to the kitchen.
Extensions in and around Chiswick
Across SW13, SW14, W3, W4, W6, W12, we can visit, measure and advise. Nearby, we also take on projects in Acton (1 mile), Barnes (1 mile), Shepherds Bush (2 miles), Notting Hill (3 miles).
Just over the Surrey border, East Molesey is about 8 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.
From first visit to completion
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
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.
Questions people ask about conservatory replacements
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.
Who do I contract with for a conservatory replacement in Chiswick?
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.
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Chiswick, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
Does replacing a conservatory need planning permission?
A solid replacement is treated as a new extension, so it must meet the permitted development limits or get planning permission, and it always needs building regulations approval.
Can I keep the existing base?
Sometimes, but conservatory bases are often too shallow for solid walls. Trial holes tell us before we confirm the price.
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.