County Durham
Rear extension plans and planning applications in County Durham
Measured survey, design options, planning drawings and the application, handled for you. We design and build rear extensions across County Durham, from Darlington and Hartlepool to Stockton-on-Tees, covering single-storey kitchen extensions, two-storey additions, side returns and wraparounds.
Rear extension applications in County Durham are householder applications, which councils aim to decide within about eight weeks. Terraces and semis are typical around County Durham. On terraces a single-storey rear extension across the back yard is usually the practical choice; semis often have room for more.
What does it cost in County Durham?
As a guide, £1,000–£2,500 including VAT. We put a fixed price in writing once the design is agreed, and explain any provisional sums such as foundations.
Do you need planning permission in County Durham?
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 County Durham 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 County Durham?
We cover 16 towns and districts in County Durham, including Darlington, Hartlepool and Stockton-on-Tees.
Who builds the extension?
Vetted building teams working under contract to us; your contract is with S&K Property Investments and Improvement Ltd.