Cambridgeshire
Rear extension plans and planning applications in Cambridgeshire
Measured survey, design options, planning drawings and the application, handled for you. Rear extensions in Cambridgeshire: we cover 11 towns including Peterborough, Cambridge and Wisbech, with design, approvals and the build under one contract.
Rear extension applications in Cambridgeshire are householder applications, which councils aim to decide within about eight weeks. Post-war semis and newer estates are typical of Cambridgeshire, and many have room for a full-width extension. Shrinkable clay is common in the East of England, so foundations near trees and hedges are designed to NHBC-style depth guidance.
What does it cost in Cambridgeshire?
As a guide, £1,000–£2,500 including VAT. Ground conditions, glazing, the roof and how far the house is opened up move the final figure within the range.
Do you need planning permission in Cambridgeshire?
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.
Conservation areas, National Parks, National Landscapes and the Broads restrict permitted development, and listed buildings always need listed building consent.
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.
Councils aim to decide householder applications within 8 weeks of validation, and prior approval within 42 days.
Where in Cambridgeshire do we work?
FAQ
Questions people ask
Do I need an architect?
You need accurate drawings by someone who knows householder planning; we provide them.
Can I see the design in 3D?
Yes; we produce simple 3D views so you can judge the size and light.
What if planning is refused?
We review the reasons with you, amend and resubmit (often free of a second fee within 12 months in England) or appeal.
Do you cover all of Cambridgeshire?
We cover 11 towns and districts in Cambridgeshire, including Peterborough, Cambridge and Wisbech.
Who builds the extension?
Vetted building teams working under contract to us; your contract is with S&K Property Investments and Improvement Ltd.