House extensions in Kent
More space without moving: we plan and build extensions across Kent, with one team for the drawings, the council and the build.
- Towns listed23
- Price regionSouth East England (×1.12)
- Planning rulesEngland
- Postcode districts73
Towns we cover in Kent
Towns we cover here include Maidstone, Gillingham, Chatham, Tunbridge Wells.
Do extensions in Kent 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 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.
Which extension suits a Kent home?
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.
Depending on the plot, wraparound extensions and orangery extensions are often the strongest options, with double-storey extensions worth considering where there is room.
Kent extension prices at a glance
We publish guide prices so you can budget before anyone visits. For Kent they are adjusted by ×1.12, the factor we use across South East England.
| Extension type | Example size | Standard spec (inc VAT) |
|---|---|---|
| Side return extensions | 11 m² | £29,500 – £37,000 |
| Kitchen extensions | 20 m² | £47,000 – £59,500 |
| Single-storey rear extensions | 20 m² | £45,500 – £58,500 |
| Double-storey extensions | 32 m² | £64,500 – £84,500 |
| Wraparound extensions | 25 m² | £64,000 – £81,500 |
| Orangery extensions | 16 m² | £50,000 – £63,000 |
All extension types we build in Kent
- Timber frame extensions · from £23,500
- Porch extensions · from £4,450
- Bungalow extensions · from £29,000
- Double-storey extensions · from £42,500
- Conservatory replacement extensions · from £22,000
- Extensions over a garage · from £26,500
- Utility and boot room extensions · from £15,500
- Pitched roof extensions · from £24,500
- Home office extensions · from £17,500
- Single-storey rear extensions · from £23,500
- Orangery extensions · from £33,500
- Side return extensions · from £20,000
- Annexe extensions · from £61,500
- Kitchen extensions · from £30,000
- Wraparound extensions · from £40,000
- Side extensions · from £24,500
- Flat roof extensions · from £23,500
- Extension plans and drawings · from £1,300
- Planning permission for extensions · from £350
- Glass box extensions · from £33,500
- Building regulations for extensions · from £1,000
- Bedroom extensions · from £29,000
Neighbouring areas
Questions about extensions in Kent
How much does an extension cost in Kent?
With our South East England factor (×1.12), a standard-spec 20 m² single-storey extension is a guide £45,500 to £58,500 including VAT. Prices for every type are linked on this page.
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 Kent?
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.
Book a free site visit in Kent
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.