Home extensions in Darlington
Looking to extend your home in Darlington? Start here: extension types, guide prices for Darlington, the planning rules that apply and how a project runs.
- Postcode districtsDL1, DL2, DL3
- Price regionNorth East England (×0.91)
- Planning rulesEngland
- Site visitFree, no obligation
Do extensions in Darlington need planning permission?
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 England a two-storey rear extension is permitted development only if it projects no more than 3 m from the original rear wall, sits at least 7 m from the rear boundary, matches the roof pitch and uses obscure, non-opening side windows upstairs. Most two-storey extensions therefore go through a householder planning application, which costs £548 from 1 April 2026 and normally takes about 8 weeks.
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.
Applications are decided by the local planning authority (your district, borough or unitary council).
Darlington extension prices at a glance
Use these Darlington guide prices to sense-check a budget; the guide-price tool narrows them to your own size, and the site visit turns them into a written figure.
| Extension type | Example size | Standard spec (inc VAT) |
|---|---|---|
| Double-storey extensions | 32 m² | £52,000 – £68,500 |
| Wraparound extensions | 25 m² | £52,000 – £66,000 |
| Kitchen extensions | 20 m² | £38,000 – £48,500 |
| Single-storey rear extensions | 20 m² | £37,000 – £47,500 |
| Orangery extensions | 16 m² | £40,500 – £51,000 |
| Extensions over a garage | 12 m² | £22,500 – £29,500 |
| Side return extensions | 11 m² | £24,000 – £30,500 |
Areas we cover around Darlington
We cover Darlington and the postcode districts DL1, DL2, DL3. We also work in nearby Newton Aycliffe (7 miles), Yarm (8 miles), Stockton-on-Tees (10 miles), Thornaby-on-Tees (10 miles), Bishop Auckland (10 miles). For homes towards North Yorkshire, Middlesbrough is around 13 miles away.
Choosing the right extension in Darlington
Across the North East, houses often have rear yards or modest gardens, so compact, well-lit single-storey extensions make the biggest difference.
Depending on the plot, kitchen extensions and single-storey rear extensions are often the strongest options, with double-storey extensions worth considering where there is room.
Choose an extension type
- Porch extensions · from £3,600
- Extensions over a garage · from £21,500
- Bungalow extensions · from £23,500
- Side extensions · from £20,000
- Bedroom extensions · from £23,500
- Side return extensions · from £16,000
- Timber frame extensions · from £19,000
- Double-storey extensions · from £34,500
- Conservatory replacement extensions · from £18,000
- Kitchen extensions · from £24,500
- Orangery extensions · from £27,000
- Pitched roof extensions · from £20,000
- Extension plans and drawings · from £1,050
- Single-storey rear extensions · from £19,000
- Glass box extensions · from £27,000
- Home office extensions · from £14,500
- Utility and boot room extensions · from £12,500
- Flat roof extensions · from £19,000
- Planning permission for extensions · from £300
- Annexe extensions · from £50,000
- Wraparound extensions · from £32,500
- Building regulations for extensions · from £800
Free site visit
We visit your Darlington home, measure up, talk through what you want and check the planning position.
Design and approvals
Once the layout is agreed, we deal with the council: planning permission or written confirmation that none is needed, plus building control.
Fixed written price
With the design and specification agreed, you get a fixed written price and a start date.
Build and sign-off
The build is managed from start to finish, inspected at each stage and signed off on completion.
Questions about extensions in Darlington
How much does an extension cost in Darlington?
Using our North East England factor (×0.91), a standard-spec single-storey extension of 20 m² is a guide £37,000 to £47,500 including VAT, and a 32 m² two-storey extension £52,000 to £68,500. Your written price follows the survey.
Do I need planning permission for an extension in Darlington?
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.
How long does an extension take in Darlington?
Usually 2 to 4 months of design and approvals, then 10 to 16 weeks on site for a single-storey extension or 16 to 24 weeks for two storeys.
Can I get a price before anyone visits?
Yes. This page shows guide prices adjusted for Darlington, and the guide-price tool gives a range for your own size and finish in about a minute.
Book a free site visit in Darlington
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.