Rear extension planning drawings in Biggin Hill

What do rear extension planning drawings cost in Biggin Hill?

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. Your written price follows a measured survey and an agreed design, so it reflects your house, not an average.

Do you need planning permission for a rear extension in Biggin Hill?

Whether your rear extension in Biggin Hill needs a planning application depends on its size, your house and any local restrictions.

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 Biggin Hill like to extend?

Around Biggin Hill 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 Biggin Hill comes together

1. Free site visit

   We measure the house and garden, look at the back wall, drainage and boundaries, and talk through what you want from the space.

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. Build and sign-off

   We build to the approved drawings with regular updates, then hand over the building control completion certificate and any guarantees from suppliers.

Rear extension planning drawings near Biggin Hill

Neighbouring places we cover include Oxted (4.3 miles) and West Wickham (4.3 miles).

• Rear extension planning drawings in Oxted
• Rear extension planning drawings in West Wickham
• Rear extension planning drawings in Orpington
• Rear extension planning drawings in Chelsfield
• Rear extension planning drawings in Sanderstead

Other work in Biggin Hill:

• Single-storey rear extension
• Two-storey rear extension
• Kitchen-diner rear extension
• Side return extension
• Wraparound extension
• Glazed rear extension

All rear extensions in Biggin Hill