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Planning permission for extensions in Tonbridge

We prepare planning permission for extensions for homes in Tonbridge, as a stand-alone service or as the first stage of a design and build project.

  • Guide price in TonbridgeFrom £350 inc VAT
  • PlanningWe find the right route for you
  • Timescale8–13 weeks typical decision period
  • Postcode districtsTN9, TN10, TN11
Homeowners reviewing extension elevation drawings and a 3D view on a tablet

What is included

  • Application forms, plans and supporting statements
  • Route recommendation in writing
  • Advice if conditions are attached or changes are requested
  • Planning history and constraints check for your address
  • Liaison with the planning officer

Planning and approvals in Tonbridge

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 Tonbridge address depends on its history and any designations, which is why we check it at the first visit.

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.

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).

Fees in Tonbridge

These are guide fees for Tonbridge, adjusted for South East England (×1.12) and including VAT. Council application and inspection fees are paid separately.

OptionWhat it coversGuide price
EssentialPermitted development confirmed in writing (certificate or notification)£350 – £750
StandardHouseholder planning application handled£650 – £1,250
PremiumApplication 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.

Try the guide-price tool to see a range for your own size and finish.

Local to Tonbridge

Our survey diary covers Tonbridge, including TN9, TN10, TN11. Neighbouring towns we cover include Tunbridge Wells (4 miles), Sevenoaks (6 miles), Maidstone (12 miles), Swanley (15 miles).

For homes towards East Sussex, Crowborough is around 10 miles away. Homes across the South East range from Victorian terraces in the older town centres to large detached houses on the edges, so the right extension type varies street by street.

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.

  1. Free site visit

    We visit your Tonbridge home, measure up, talk through what you want and check the planning position.

  2. 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.

  3. Fixed written price

    The price is fixed in writing once the design is settled, with a clear programme and payment stages.

  4. Build and sign-off

    The build is managed from start to finish, inspected at each stage and signed off on completion.

Questions answered

Can I see a price before committing to anything?

Yes. The guide prices on this page are adjusted for Tonbridge, 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 you cover all of Tonbridge?

Yes. We cover Tonbridge and the surrounding parts of Kent. Site visits are free and there is no obligation.

How long does this take for a Tonbridge home?

8–13 weeks typical decision period, depending on the council and the complexity of the project.

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.

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.

Book a free site visit in Tonbridge

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

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