Spennymoor, County Durham
Semi-detached rear extension in Spennymoor
Single or two-storey extensions for semi-detached houses, with side access and one party wall. If you live in Spennymoor and want to know what a semi-detached rear extension would cost and whether it needs planning, start with the online guide price or a free site visit.
We cover Spennymoor (DL16) as part of our County Durham work. Where a Spennymoor semi already has a small lean-to at the back, we usually replace it rather than extend it.
Book a free site visit
Tell us about the house and we'll call to arrange a free, no-obligation visit.
How much does a semi-detached rear extension cost in Spennymoor?
In Spennymoor, our guide for a semi-detached rear extension is £1,710–£2,790 per square metre including VAT for a 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 |
These are guide ranges; the written quote after the survey is the figure that counts.
Do you need planning permission for a semi-detached rear extension in Spennymoor?
The planning route for a semi-detached rear extension in Spennymoor is set by England's householder rules and your council.
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.
A two-storey rear extension can be permitted development in England only if it projects no more than 3 metres, stays at least 7 metres from the rear boundary, matches the existing roof pitch and has obscure-glazed upper side windows. In practice most double-storey rear extensions go through a householder planning application.
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.
Conservation areas, National Parks, National Landscapes and the Broads restrict permitted development, and listed buildings always need listed building consent. We check your house's planning history and any conservation area before drawing, so the route is clear before you spend on plans.
What are homes in Spennymoor like to extend?
Brick terraces, colliery houses and post-war semis make up much of Spennymoor. Former mining areas often need a coal mining risk check before foundations are designed.
How a semi-detached rear extension in Spennymoor comes together
Look round and measure
A free visit to see the back of the house, measure it, check the drains and boundaries and hear what you need.
Options and costs
We draw layout options and price each one, so the budget shapes the design rather than surprising you later.
Planning and regulations
We take the design through the right planning route, then produce the construction drawings and engineer's calculations for building control.
Written price, then build
Once the design and approvals are in place, you get a fixed written price and programme, and we build through to sign-off.
Semi-detached rear extensions near Spennymoor
Close by, we work in Bishop Auckland, about 4.2 miles away, and Durham, about 5.5 miles away.
- Semi-detached rear extension in Bishop Auckland
- Semi-detached rear extension in Durham
- Semi-detached rear extension in Newton Aycliffe
- Semi-detached rear extension in Hetton-le-Hole
- Semi-detached rear extension in Chester-le-Street
Other work in Spennymoor:
FAQ
Semi-detached rear extension questions in Spennymoor
How much does a semi-detached rear extension cost in Spennymoor?
As a guide, £1,710–£2,790 per square metre including VAT for a standard specification. For example, 3 m wide × 4 m deep (12 m²): about £20,500–£33,500 at that rate. Your written price follows the survey.
Do you handle building control in Spennymoor?
Yes. We apply to the council or a registered building control approver and hand over the completion certificate.
Can I match pebbledash or render?
Yes. Many semis are refinished with new render across the whole back elevation so old and new match.
Can I live at home while the extension is built?
Usually yes. Most of the work is outside until the back wall is opened near the end, and that stage is screened off.
What postcode areas do you cover around Spennymoor?
Including DL16, and the surrounding County Durham area.
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.