West Sussex
Rear extension plans and planning applications in West Sussex
Measured survey, design options, planning drawings and the application, handled for you. Rear extensions in West Sussex: we cover 15 towns including Crawley, Worthing and Bognor Regis, with design, approvals and the build under one contract.
Planning applications in Crawley go to the local planning authority, and we check its local design guidance for rear extensions before drawing. West Sussex has a mix of Victorian terraces near the centre and larger Edwardian and inter-war houses further out. Clay soils across much of the South East mean deeper foundations near trees, which we plan for at the survey.
What does it cost in West Sussex?
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 West Sussex?
England's rules allow a rear extension of more than one storey without an application only when it is no deeper than 3 metres and at least 7 metres from the boundary opposite the rear wall, and never on designated land. Most two-storey schemes need householder planning permission.
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 West Sussex 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 West Sussex?
We cover 15 towns and districts in West Sussex, including Crawley, Worthing and Bognor Regis.
Who builds the extension?
Vetted building teams working under contract to us; your contract is with S&K Property Investments and Improvement Ltd.