Planning permission for extensions in Folkestone
For Folkestone homeowners we handle planning permission for extensions, with fees agreed in writing before any work starts.
- Guide price in FolkestoneFrom £350 inc VAT
- PlanningWe find the right route for you
- Timescale8–13 weeks typical decision period
- Postcode districtsCT18, CT19, CT20

Covering Folkestone
Our survey diary covers Folkestone, including CT18, CT19, CT20. Nearby, we also take on projects in Dover (7 miles), Ashford, Kent (13 miles), Deal (14 miles), Canterbury (14 miles).
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.
When it helps
- Homeowners who would rather not deal with the council themselves
- Projects in conservation areas or with previous refusals
- Anyone unsure whether their extension needs permission
A lawful development certificate is not compulsory for permitted development, but it is the cleanest proof that the extension was lawful when you come to sell. We usually recommend one.
What it costs in Folkestone
Guide fees for Folkestone including VAT, using our South East England factor of ×1.12. Council and building control charges are not included.
| Option | What it covers | Guide price |
|---|---|---|
| Essential | Permitted development confirmed in writing (certificate or notification) | £350 – £750 |
| Standard | Householder planning application handled | £650 – £1,250 |
| Premium | Application with heritage or design statements, and responses to the council | £1,000 – £1,800 |
Our handling fee only. Council fees are extra: in England from 1 April 2026 a householder application is £548, a lawful development certificate for a proposed extension £274 and a larger home extension prior approval £249. Drawings are priced separately.
For a figure based on your own dimensions, use our guide-price tool.
Planning rules that apply in Folkestone
In England the main routes are permitted development (ideally confirmed with a lawful development certificate, £274), larger home extension prior approval (£249, 42 days) and a householder planning application (£548, normally 8 weeks), with council fees as set from 1 April 2026.
The planning position for a specific Folkestone address depends on its history and any designations, which is why we check it at the first visit.
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.
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
We produce the drawings and structural design, and manage the approvals so they are in place before work starts.
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.
Common questions in Folkestone
Will my neighbours in Folkestone be involved?
If a planning application or prior approval is needed, the council notifies neighbours. If the work is on or near a shared boundary, party wall notices may also be needed.
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Folkestone, 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 I need building regulations approval in Folkestone?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
What happens if planning is refused?
You can revise the design and reapply, or appeal. We read the officer’s report and tell you honestly which option has a better chance.
How much does planning permission cost?
In England, from 1 April 2026 the council fee is £548 for a householder application, £274 for a lawful development certificate for a proposed extension and £249 for larger home extension prior approval. Our handling fee is separate.
Book a free site visit in Folkestone
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.