County Durham house extensions
More space without moving: we plan and build extensions across County Durham, with one team for the drawings, the council and the build.
- Towns listed14
- Price regionNorth East England (×0.91)
- Planning rulesEngland
- Postcode districts35
Towns we cover in County Durham
Towns we cover here include Darlington, Hartlepool, Stockton-on-Tees, Durham.
Planning rules in County Durham
In England a single-storey rear extension can usually go up to 3 m beyond the original rear wall of a semi-detached or terraced house, or 4 m on a detached house, without a planning application, provided it is no more than 4 m high, keeps eaves to 3 m within 2 m of a boundary and, with other buildings, covers no more than half the land around the original house. The larger home extension prior approval scheme raises those depths to 6 m and 8 m, with neighbours notified and a 42-day decision.
In a conservation area, national park, National Landscape, the Broads or a World Heritage Site the permitted development limits are tighter (no side or two-storey extensions without an application). Listed homes need listed building consent, and if permitted development rights have been removed, any extension needs an application.
Building regulations approval is separate from planning. In England you can use the council's building control team or a registered building control approver; a full plans application gets the drawings checked before work starts, and the inspector signs the work off with a completion certificate.
What extensions cost in County Durham
Every figure below is a guide for County Durham, adjusted for North East England build costs (×0.91) and including VAT. Design and council fees are shown separately on each page.
| Extension type | Example size | Standard spec (inc VAT) |
|---|---|---|
| Single-storey rear extensions | 20 m² | £37,000 – £47,500 |
| Double-storey extensions | 32 m² | £52,000 – £68,500 |
| Kitchen extensions | 20 m² | £38,000 – £48,500 |
| Conservatory replacement extensions | 14 m² | £27,000 – £35,500 |
| Wraparound extensions | 25 m² | £52,000 – £66,000 |
| Orangery extensions | 16 m² | £40,500 – £51,000 |
What works best for County Durham houses?
The North East has many brick terraces, colliery-era housing and post-war semis, with rear extensions and kitchen extensions the most common requests.
For many houses here, kitchen extensions, utility and boot room extensions or double-storey extensions gives the most useful space for the budget.
Every extension type in County Durham
- Flat roof extensions · from £19,000
- Extensions over a garage · from £21,500
- Bungalow extensions · from £23,500
- Double-storey extensions · from £34,500
- Side return extensions · from £16,000
- Orangery extensions · from £27,000
- Building regulations for extensions · from £800
- Kitchen extensions · from £24,500
- Pitched roof extensions · from £20,000
- Home office extensions · from £14,500
- Timber frame extensions · from £19,000
- Planning permission for extensions · from £300
- Extension plans and drawings · from £1,050
- Wraparound extensions · from £32,500
- Glass box extensions · from £27,000
- Porch extensions · from £3,600
- Side extensions · from £20,000
- Bedroom extensions · from £23,500
- Utility and boot room extensions · from £12,500
- Conservatory replacement extensions · from £18,000
- Single-storey rear extensions · from £19,000
- Annexe extensions · from £50,000
Neighbouring areas
Questions about extensions in County Durham
How much does an extension cost in County Durham?
With our North East England factor (×0.91), a standard-spec 20 m² single-storey extension is a guide £37,000 to £47,500 including VAT. Prices for every type are linked on this page.
Do you handle building regulations?
Yes. We prepare the drawings and calculations, submit them and book inspections, ending with a completion certificate.
Do I need planning permission for an extension in County Durham?
Not always. It depends on the size, position and your property's history. Many single-storey rear extensions in England are permitted development or can use prior approval.
Can I get a price before anyone visits?
Yes. This page shows guide prices adjusted for County Durham, and the guide-price tool gives a range for your own size and finish in about a minute.
Book a free site visit in County Durham
We will measure up, check the planning position and give you honest guide figures.
- Free, no-obligation site visit
- Planning route checked before you spend on drawings
- Written price once the design is agreed
- Building control sign-off at the end
Prefer to talk? Call 0800 088 6341 or .
Book a free site visit
Tell us a little about the project and we will arrange a time.