Covering Darlington
Our coverage around Darlington (DL3, DL98) also includes Newton Aycliffe, Stockton-on-Tees and Thornaby-on-Tees.
Homes in the North East
Housing across the North East ranges from colliery terraces and Tyneside flats to suburban semis and modern estates, each with different options for extending.
What do you get with a single-storey extension?
We design the extension around how you use the house: where the light comes from, how the new room joins the old one, and what happens to the drains and the garden. The structure is built in brick or block to match the house, finished with a flat roof and lantern or a pitched roof, then insulated, plastered and handed back ready to decorate.
- Measured survey and design drawings
- Building control application and inspections
- Foundations, drainage and structural steel
How much does a single-storey extension cost in Darlington?
What single-storey extensions typically cost. These are guide ranges; the written quote for your house replaces them.
| Single-storey extensions | Guide price incl. VAT |
|---|---|
| Standard specification | £2,600 to £3,000 per m² |
| Good specification | £3,000 to £3,500 per m² |
| High specification | £3,500 to £4,000 per m² |
Do you need permission for a single-storey extension in Darlington?
English projects need planning clearance from the local council, building regulations sign-off from building control, and party wall notices where the work is on or near a shared boundary. We prepare and manage all three.
In England a single-storey rear extension can often go ahead under permitted development: up to 3 m deep on an attached house or 4 m on a detached one, no higher than 4 m, with eaves no higher than 3 m within 2 m of a boundary. Deeper extensions, up to 6 m or 8 m, need prior approval from the council first.
What should I think about before starting?
- Drains under the footprint may need diverting or a build-over agreement with the water company.
- Large glazed areas need to meet energy rules, which can shape the size of doors and rooflights.
What are the steps?
- Send us the details. Give us a postcode, a rough idea of size and some photos, by phone, form or the guide price tool.
- We visit and measure. A surveyor checks the house, the boundaries and the ground, and discusses what is realistic.
- Drawings, approvals, written quote. We prepare the design, apply for the approvals it needs, and give you a fixed price in writing.
- We build it. Work follows an agreed programme, with inspections at each stage and a final sign-off.
Your questions answered
Do I need planning permission for a single-storey extension?
Often not in England, if the extension stays within permitted development limits: 3 m deep on an attached house or 4 m on a detached house, and no higher than 4 m. Larger ones need prior approval or a planning application. Wales, Scotland and Northern Ireland have their own rules.
Do you need to dig up the drains?
Sometimes. If a public sewer runs under the extension, the water company has to agree a build-over or a diversion. We check this at survey stage.
Can you visit a house in Darlington to quote?
Yes. After a short call we arrange a site visit to measure up and agree what the design needs to do, then send a written price.
Single-storey extensions near Darlington
- Single-storey extensions in Newton Aycliffe
- Single-storey extensions in Stockton-on-Tees
- Single-storey extensions in Thornaby-on-Tees
- Single-storey extensions in Bishop Auckland
Learn more about single-storey extensions, or see every project we cover in Darlington.

