Extensions in Tonbridge: design, planning and build
More space without moving: we plan and build extensions across Tonbridge, with one team for the drawings, the council and the build.
- Postcode districtsTN9, TN10, TN11
- Price regionSouth East England (×1.12)
- Planning rulesEngland
- Site visitFree, no obligation
Where we work near Tonbridge
Across TN9, TN10, TN11, we can visit, measure and advise. The same team covers Tunbridge Wells (4 miles), Sevenoaks (6 miles), Maidstone (12 miles), Swanley (15 miles), Strood (16 miles), all within easy reach. Just over the East Sussex border, Crowborough is about 10 miles away.
Do extensions in Tonbridge need planning permission?
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 England a single-storey side return infill is often permitted development if it stays within the height limits and is no wider than half the width of the original house. Conservation areas, listed buildings and flats always need an application, and the boundary wall usually brings in the Party Wall Act.
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.
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).
Choosing the right extension in Tonbridge
The South East has a broad mix of 1930s semis, post-war estates, newer developments and period cottages, and many houses have enough garden for a generous rear extension.
For many houses here, orangery extensions, double-storey extensions or single-storey rear extensions gives the most useful space for the budget.
Tonbridge extension prices at a glance
Use these Tonbridge guide prices to sense-check a budget; the guide-price tool narrows them to your own size, and the site visit turns them into a written figure.
| Extension type | Example size | Standard spec (inc VAT) |
|---|---|---|
| Orangery extensions | 16 m² | £50,000 – £63,000 |
| Side return extensions | 11 m² | £29,500 – £37,000 |
| Kitchen extensions | 20 m² | £47,000 – £59,500 |
| Extensions over a garage | 12 m² | £28,000 – £36,500 |
| Double-storey extensions | 32 m² | £64,500 – £84,500 |
| Single-storey rear extensions | 20 m² | £45,500 – £58,500 |
| Wraparound extensions | 25 m² | £64,000 – £81,500 |
Choose an extension type
- Bedroom extensions · from £29,000
- Home office extensions · from £17,500
- Glass box extensions · from £33,500
- Building regulations for extensions · from £1,000
- Pitched roof extensions · from £24,500
- Flat roof extensions · from £23,500
- Planning permission for extensions · from £350
- Utility and boot room extensions · from £15,500
- Timber frame extensions · from £23,500
- Single-storey rear extensions · from £23,500
- Double-storey extensions · from £42,500
- Side extensions · from £24,500
- Annexe extensions · from £61,500
- Bungalow extensions · from £29,000
- Side return extensions · from £20,000
- Conservatory replacement extensions · from £22,000
- Porch extensions · from £4,450
- Wraparound extensions · from £40,000
- Extensions over a garage · from £26,500
- Extension plans and drawings · from £1,300
- Kitchen extensions · from £30,000
- Orangery extensions · from £33,500
Free site visit
We visit your Tonbridge home, measure up, talk through what you want and check the planning position.
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
With the design and specification agreed, you get a fixed written price and a start date.
Build and sign-off
We build it with one project manager, book the building control inspections and hand over the completion certificate.
Questions about extensions in Tonbridge
How much does an extension cost in Tonbridge?
Using our South East England factor (×1.12), a standard-spec single-storey extension of 20 m² is a guide £45,500 to £58,500 including VAT, and a 32 m² two-storey extension £64,500 to £84,500. Your written price follows the survey.
Who do I contract with?
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.
Do you handle building regulations?
Yes. We prepare the drawings and calculations, submit them and book inspections, ending with a completion certificate.
How long does an extension take in Tonbridge?
Usually 2 to 4 months of design and approvals, then 10 to 16 weeks on site for a single-storey extension or 16 to 24 weeks for two storeys.
Do you cover all of Tonbridge?
Yes, including the surrounding parts of Kent. Site visits are free and there is no obligation.
Book a free site visit in Tonbridge
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.