Conservatory replacement extensions for homes in Sevenoaks
A conservatory replacement in Sevenoaks starts with the right design and the right approval route. We take care of both, then build it with our own project management.
- Guide price in SevenoaksFrom £22,000 inc VAT
- PlanningOften permitted development (3–4 m), or prior approval up to 6–8 m
- Build time8–14 weeks on site
- Postcode districtsTN13, TN14

What we take care of
- Removal and disposal of the old conservatory
- Trial holes to check the existing foundations
- Opening widened into the house if wanted
- Insulated walls and roof to current regulations
- Glazing and doors to suit the new room
- New or upgraded foundations
Local to Sevenoaks
Site visits are available across Sevenoaks (TN13, TN14). We also work in nearby Tonbridge (6 miles), Swanley (9 miles), Tunbridge Wells (10 miles), Dartford (12 miles).
Homes across the South East range from Victorian terraces in the older town centres to large detached houses on the edges, so the right extension type varies street by street.
What should I budget for a conservatory replacement in Sevenoaks?
Labour and material costs vary across the UK, so for Sevenoaks we use our South East England factor (×1.12). The ranges include VAT and exclude design, structural and council fees.
Typical rates in Sevenoaks: £2,070 to £3,920 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 3 m × 3.3 m 10 m² | £22,000 – £27,000 | £24,000 – £31,000 | £30,500 – £39,500 |
| 3.5 m × 4 m 14 m² | £29,000 – £34,500 | £33,500 – £43,500 | £43,000 – £55,000 |
| 4 m × 5 m 20 m² | £41,000 – £49,500 | £48,000 – £62,000 | £61,500 – £78,500 |
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.
Planning and approvals in Sevenoaks
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.
In a conservation area, national park, National Landscape, the Broads or a World Heritage Site the permitted development limits are tighter (no side or two-storey extensions without an application). Listed homes need listed building consent, and if permitted development rights have been removed, any extension needs an application.
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.
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).
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
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
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.
Conservatory replacement questions answered
Do I need building regulations approval in Sevenoaks?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Sevenoaks, 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 Sevenoaks?
Yes. We cover Sevenoaks and the surrounding parts of Kent. Site visits are free and there is no obligation.
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.
Is it worth replacing a conservatory with an extension?
If the conservatory is unusable for much of the year, usually yes. A solid extension gives a heated room that counts as proper living space. Our guide range is about £2,070 to £3,920 per m² including VAT, including removal.
Book a free site visit in Sevenoaks
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.