Planning permission for extensions in Sevenoaks
We prepare planning permission for extensions for homes in Sevenoaks, as a stand-alone service or as the first stage of a design and build project.
- Guide price in SevenoaksFrom £350 inc VAT
- PlanningWe find the right route for you
- Timescale8–13 weeks typical decision period
- Postcode districtsTN13, TN14
Local to Sevenoaks
Our survey diary covers Sevenoaks, including TN13, TN14. Neighbouring towns we cover include Tonbridge (6 miles), Swanley (9 miles), Tunbridge Wells (10 miles), Dartford (12 miles).
Just over the Greater London border, Orpington is about 8 miles away. 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.
What it costs in Sevenoaks
Guide fees for Sevenoaks 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.
What we take care of
- Advice if conditions are attached or changes are requested
- Planning history and constraints check for your address
- Submission and fee payment guidance
- Route recommendation in writing
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.
Planning rules that apply in Sevenoaks
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.
Homes in conservation areas, national parks, National Landscapes (formerly AONBs), the Broads and World Heritage Sites have tighter rules, so we always check the property's status and planning history before design starts.
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.
Applications are decided by the local planning authority (your district, borough or unitary council).
Our process, step by step
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
It starts with a visit to your house to measure, check access and talk through ideas and budget.
Design and approvals
Once the layout is agreed, we deal with the council: planning permission or written confirmation that none is needed, plus building control.
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.
Common questions in Sevenoaks
How long does this take for a Sevenoaks home?
8–13 weeks typical decision period, depending on the council and the complexity of the project.
Who do I contract with in Sevenoaks?
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.
Will my neighbours in Sevenoaks 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.
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 Sevenoaks
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.