House extensions in Tunbridge Wells

Choosing the right extension in Tunbridge Wells

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.

For many houses here, single-storey rear extensions, double-storey extensions or wraparound extensions gives the most useful space for the budget.

Tunbridge Wells and surrounding towns

Our survey diary covers Tunbridge Wells, including TN1, TN2, TN3, TN4. The same team covers Tonbridge (4 miles), Sevenoaks (10 miles), Maidstone (14 miles), Swanley (19 miles), Strood (20 miles), all within easy reach. Crowborough, in East Sussex, is roughly 7 miles from Tunbridge Wells and also on our list.

• Tonbridge
• Sevenoaks
• Maidstone
• Swanley
• Strood

Do extensions in Tunbridge Wells need planning permission?

In England a single-storey rear extension can usually go up to 3 m beyond the original rear wall of a semi-detached or terraced house, or 4 m on a detached house, without a planning application, provided it is no more than 4 m high, keeps eaves to 3 m within 2 m of a boundary and, with other buildings, covers no more than half the land around the original house. The larger home extension prior approval scheme raises those depths to 6 m and 8 m, with neighbours notified and a 42-day decision.

In England a two-storey rear extension is permitted development only if it projects no more than 3 m from the original rear wall, sits at least 7 m from the rear boundary, matches the roof pitch and uses obscure, non-opening side windows upstairs. Most two-storey extensions therefore go through a householder planning application, which costs £548 from 1 April 2026 and normally takes about 8 weeks.

In a conservation area, national park, National Landscape, the Broads or a World Heritage Site the permitted development limits are tighter (no side or two-storey extensions without an application). Listed homes need listed building consent, and if permitted development rights have been removed, any extension needs an application.

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.

Applications are decided by the local planning authority (your district, borough or unitary council).

Popular extension prices in Tunbridge Wells

Every figure below is a guide for Tunbridge Wells, adjusted for South East England build costs (×1.12) and including VAT. Design and council fees are shown separately on each page.