County Durham
Larger home extension prior approval (England) in County Durham
Up to 6 m (attached) or 8 m (detached) deep, after neighbour consultation. Rear extensions in County Durham: we cover 16 towns including Darlington, Hartlepool and Stockton-on-Tees, with design, approvals and the build under one contract.
Brick terraces, colliery houses and post-war semis make up much of County Durham. Former mining areas often need a coal mining risk check before foundations are designed.
How much does a prior approval rear extension cost in County Durham?
For County Durham we work from the North East England rate: £1,710–£2,790 per square metre of new floor, including VAT, standard specification. North East prices are among the lowest in our range; former mining ground is the main foundation variable.
| Size | Guide price inc VAT |
|---|---|
| 3 m wide × 4 m deep (12 m²) | £20,500–£33,500 |
| 4 m wide × 5 m deep (20 m²) | £34,000–£56,000 |
| 4 m wide × 6 m deep (24 m²) | £41,000–£67,000 |
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?
England also has the larger home extension route: a single-storey rear extension of up to 6 metres on an attached house or 8 metres on a detached house, after prior approval from the council. The council notifies your neighbours and has 42 days to decide; the fee is £249 (£310 for applications made from 8 December 2026). The route is not available on designated land such as conservation areas.
Conservation areas, National Parks, National Landscapes and the Broads restrict permitted development, and listed buildings always need listed building consent.
Where in County Durham do we work?
FAQ
Questions people ask
How deep can I go with prior approval?
6 metres on attached houses and 8 metres on detached houses, single-storey only, up to 4 metres high.
Can my neighbours stop it?
They can object; the council then judges the effect on their amenity. Many schemes are approved after objections.
What happens after 42 days?
If the council has not decided, you can proceed. We still recommend waiting for written confirmation where possible.
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.