County Durham
Rear extensions in Darlington
From the first measured visit to building control sign-off, we handle rear extensions in Darlington under one contract.
Darlington is in County Durham, with postcode districts including DL1, DL2 and DL3. The nearest places we also cover are Newton Aycliffe (6.6 miles) and Yarm (7.9 miles).
Book a free site visit
Tell us about the house and we'll call to arrange a free, no-obligation visit.
Rear extensions we build in Darlington
- Single-storey rear extensions
- Two-storey rear extensions
- Kitchen-diner rear extensions
- Side return extensions
- Wraparound extensions
- Glazed and glass-box rear extensions
- Rear extensions for terraced houses
- Rear extensions for semi-detached houses
- Rear extensions for bungalows
- Rear extension plans and planning applications
Also available across County Durham:
- Rear extensions for detached houses
- Flat-roof rear extensions
- Pitched and lean-to roof rear extensions
- Knocking through to a rear extension
- Roof lanterns and rooflights for rear extensions
- Permitted development rear extensions
- Larger home extension prior approval (England)
- Building Regulations for rear extensions
Rear extension prices in Darlington
North East prices are among the lowest in our range; former mining ground is the main foundation variable.
| Example | Guide inc VAT |
|---|---|
| Single-storey, 3 m × 4 m (12 m²) | £20,500–£33,500 |
| Single-storey, 4 m × 6 m (24 m²) | £41,000–£67,000 |
| Two-storey, 3 m × 5 m footprint (30 m²) | £48,500–£73,000 |
| Side return, about 14 m² | £29,000–£48,000 |
| Wraparound, about 25 m² | £49,500–£81,000 |
What are homes in Darlington like to extend?
Terraces and semis are typical around Darlington. On terraces a single-storey rear extension across the back yard is usually the practical choice; semis often have room for more.
Planning rules for Darlington
Under England's householder permitted development rules you can usually add 3 metres at the back of an attached house, or 4 metres on a detached house, without a planning application, as long as the extension stays under 4 metres high and its eaves stay under 3 metres where it is within 2 metres of a boundary.
If 3 or 4 metres is not enough, England's prior approval route allows 6 metres on a terraced or semi-detached house and 8 metres on a detached house for a single-storey rear extension. Neighbours are consulted, the council decides within 42 days, and the fee is £249, rising to £310 from 8 December 2026.
Planning and Building Regulations are separate in England: even a permitted development extension is inspected for foundations, drainage, structure, insulation, fire safety and ventilation, through the council or a registered building control approver, ending with a completion certificate.
Nearby towns
FAQ
Questions people ask
How much is a rear extension in Darlington?
A 3 m × 4 m single-storey rear extension is about £20,500–£33,500 including VAT at our North East England guide rates; the written price follows a survey.
Do I need planning permission in Darlington?
Often not for a single-storey rear extension of up to 3 metres (4 metres on a detached house) under permitted development, or up to 6 or 8 metres with prior approval, unless the house is in a conservation area or its rights have been removed.
Is the site visit in Darlington free?
Yes, with no obligation.
Do I need a party wall agreement?
In England, usually yes if the extension is on or near a shared boundary or the foundations are close to a neighbour's building. We serve the notices.