Kent
Permitted development rear extensions in Kent
Designing to the no-application limits, with a lawful development certificate as proof. We design and build rear extensions across Kent, from Maidstone and Gillingham to Chatham, covering single-storey kitchen extensions, two-storey additions, side returns and wraparounds.

Kent has a mix of Victorian terraces near the centre and larger Edwardian and inter-war houses further out. Clay soils across much of the South East mean deeper foundations near trees, which we plan for at the survey.
How much does a permitted development rear extension cost in Kent?
A permitted development rear extension in Kent is priced at £2,130–£3,470 per square metre including VAT as a guide, before kitchen fit-out and fees. South East prices run above our West Midlands baseline, mainly on labour rates and clay-soil foundations.
| Size | Guide price inc VAT |
|---|---|
| 3 m wide × 4 m deep (12 m²) | £25,500–£41,500 |
| 4 m wide × 5 m deep (20 m²) | £42,500–£69,500 |
| 4 m wide × 6 m deep (24 m²) | £51,000–£83,500 |
Ground conditions, glazing, the roof and how far the house is opened up move the final figure within the range.
Do you need planning permission in Kent?
In England a single-storey rear extension can often be built under permitted development: up to 3 metres beyond the original rear wall of an attached house, or 4 metres on a detached house, no higher than 4 metres, with eaves no higher than 3 metres if any part is within 2 metres of a boundary.
England's rules allow a rear extension of more than one storey without an application only when it is no deeper than 3 metres and at least 7 metres from the boundary opposite the rear wall, and never on designated land. Most two-storey schemes need householder planning permission.
Conservation areas, National Parks, National Landscapes and the Broads restrict permitted development, and listed buildings always need listed building consent.
Where in Kent do we work?
FAQ
Questions people ask
Is permitted development the same as planning permission?
No; it is a national grant of permission for work within set limits, so no application is needed.
Do I still need Building Regulations?
Yes, always.
Can my neighbours object?
Not to permitted development itself, though they can ask the council to check it complies. Prior approval does involve neighbour consultation.
Do you cover all of Kent?
We cover 31 towns and districts in Kent, including Maidstone, Gillingham and Chatham.
Who builds the extension?
Vetted building teams working under contract to us; your contract is with S&K Property Investments and Improvement Ltd.