Planning permission for two-storey extensions in Kent

Kent at a glance

Nation: England
Price region: South East England
Postcode areas: BR, CT, DA, ME, TN
Towns covered: 31 listed below, plus surrounding villages
Site visits: Free, no obligation

What a planning application involves

Getting planning permission for a two-storey extension involves checking whether permitted development applies, preparing drawings and supporting information, submitting a householder application to the council and dealing with questions until a decision is made. Many two-storey extensions need permission, especially side, wraparound and front ones.

Across Kent we cover Maidstone (ME14), Gillingham (ME3), Chatham (ME4), Tunbridge Wells (TN1), Folkestone (CT18) and Margate (CT9), plus the smaller places around them.

Fees

Planning drawings are a guide of £2,000–£3,500, priced in writing before the design stage starts. Householder planning application: £548 (or £575 for applications made from 8 December 2026). Lawful development certificate: £274 (about £288 for applications from 8 December 2026).

Rules in England

In England, a householder planning application costs £548 (or £575 for applications made from 8 December 2026), and councils should decide within 8 weeks of validation. Two-storey side, wraparound and front extensions always need permission. Rear extensions may be permitted development within the 3 m and 7 m limits, confirmed with a lawful development certificate costing £274 (about £288 for applications from 8 December 2026).

Approval in England: Householder planning application: £548 (or £575 for applications made from 8 December 2026). Lawful development certificate: £274 (about £288 for applications from 8 December 2026). Councils should decide householder applications within 8 weeks of validation.

Building regulations: Building regulations approval (full plans recommended) from the council or a registered building control approver, with a completion certificate at the end.

The Party Wall etc. Act 1996 applies, so notices may be needed for work on or near a shared wall or boundary.

Getting the design right

Neighbours' light and privacy

The main concerns on a two-storey extension are usually loss of light, outlook and privacy for neighbours. We test the design against nearby windows and gardens, and adjust depth, roof shape or window positions before submitting.

A complete application

Applications that are missing drawings, the right fee or a certificate of ownership are not validated, and the decision clock does not start. We check the council's validation list so the application is complete on day one.

How we work in Kent

Visit and first ideas
One of our team visits your house in Kent, checks the walls, roof and drains, and sketches out options with you.
Choose the approval route
Some designs fit permitted development, most need a householder application. We decide which applies in England before drawing in detail.
Technical design
We prepare the building regulations drawings, structural calculations and specification so the build price can be fixed.
Build it
The new structure goes up first, then we open into the house, finish inside and get the completion certificate.

Towns we cover in Kent

Planning permission for two-storey extensions in Kent: questions

What happens if my planning application is refused?

You can change the design and apply again, or appeal. In England, a householder appeal must usually be made within 12 weeks of the decision. Often the best route is a revised design that answers the reasons for refusal. We read the officer's report and advise which option has the better chance.

Should I get pre-application advice from the council?

It can help on sensitive sites, such as conservation areas, corner plots or front extensions, where the council's view is hard to predict. Many councils charge for it and response times vary. For straightforward designs that follow local guidance, a well prepared application is often the quicker route.

Neighbouring areas

All extension services in Kent · About planning permission for two-storey extensions