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Tonbridge, Kent

Rear extension planning drawings in Tonbridge

Rear extension planning drawings in Tonbridge: measured survey, design options, planning drawings and the application, handled for you. We measure the house, show you what the rules allow, price it in writing and build it.

Tonbridge sits in Kent, with postcode districts including TN9, TN10 and TN11. Planning applications in Tonbridge go to the local planning authority covering Tonbridge, and we check its local design guidance for rear extensions before drawing.

Book a free site visit

Tell us about the house and we'll call to arrange a free, no-obligation visit.

What do rear extension planning drawings cost in Tonbridge?

As a guide, £1,000–£2,500 including VAT for a single-storey rear extension, or £2,000–£3,500 for a two-storey scheme. A householder planning application in England costs £548 (£575 for applications made from 8 December 2026), and a lawful development certificate for proposed work costs half the householder fee. These are guide ranges; the written quote after the survey is the figure that counts.

Do you need planning permission for a rear extension in Tonbridge?

Planning for a rear extension in Tonbridge follows the English householder rules.

A two-storey rear extension can be permitted development in England only if it projects no more than 3 metres, stays at least 7 metres from the rear boundary, matches the existing roof pitch and has obscure-glazed upper side windows. In practice most double-storey rear extensions go through a householder planning application.

Councils aim to decide householder applications within 8 weeks of validation, and prior approval within 42 days.

Conservation areas, National Parks, National Landscapes and the Broads restrict permitted development, and listed buildings always need listed building consent. We check your house's planning history and any conservation area before drawing, so the route is clear before you spend on plans.

What are homes in Tonbridge like to extend?

Around Tonbridge the housing ranges from inter-war semis to 1960s and 1970s estates with good-sized gardens. Many of the newer estates had permitted development rights removed by condition, so we check the planning history before anything is drawn.

How a rear extension in Tonbridge comes together

  1. Survey visit

    We visit free of charge, measure up, check access, drainage and neighbours' extensions, and note what you want the room to do.

  2. Design and guide price

    Two or three layout options with a guide price for each, so you choose the design knowing what it costs.

  3. Approvals

    Permitted development check, prior approval or planning application, then Building Regulations drawings and structural calculations, plus party wall notices where they apply.

  4. Fixed price and build

    A written price for the agreed design, a start date and a named contact through the build, ending with the building control completion certificate.

Rear extension planning drawings near Tonbridge

Close by, we work in Royal Tunbridge Wells, about 4.3 miles away, and Sevenoaks, about 6.5 miles away.

Other work in Tonbridge:

All rear extensions in Tonbridge

FAQ

Rear extension planning drawings questions in Tonbridge

Will I need a structural engineer?

Yes for the beam over the new opening and usually the foundations; we arrange them and their calculations go to building control.

What do rear extension planning drawings cost in Tonbridge?

As a guide, £1,000–£2,500 including VAT for a single-storey rear extension and £2,000–£3,500 for a two-storey scheme, covering the measured survey, design options and the application. The council fee is extra.

Can planning conditions affect the build?

Yes, for example matching materials or obscure glazing. We plan for them.

Do I need a party wall agreement?

In England, usually yes if the extension is on or near a shared boundary or the foundations are close to a neighbour's building. We serve the notices.

What postcode areas do you cover around Tonbridge?

Including TN9, TN10 and TN11, and the surrounding Kent area.

Do you handle building control in Tonbridge?

Yes. We apply to the council or a registered building control approver and hand over the completion certificate.

Next step

See what your rear extension would cost

Get a guide price online in a couple of minutes, or book a free site visit and we'll measure up and talk you through the planning route.

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