What is a single-storey extension?
A single-storey extension is a ground-floor addition, usually at the rear of a house, that enlarges a kitchen, living or dining space. Most are built with cavity walls on concrete foundations and finished with a flat roof and roof lantern or a pitched tiled roof.
How much does a single-storey extension cost in Stanley?
In Stanley, a single-storey extension typically costs £1,750–£2,600 per m² of floor area, including VAT at 20% (standard rate). For a typical 20 m² project that is roughly £35,000–£52,000. We start from a UK-wide guide and adjust it for the North East, where labour and materials are typically about 10% below average. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (14 m²) | £24,500–£36,500 |
| Typical project (20 m²) | £35,000–£52,000 |
| Larger project (28 m²) | £49,000–£73,000 |
| Rate per m² | £1,750–£2,600 |
The biggest cost drivers are:
- Roof type and the size of any lantern or roof windows
- Ground conditions and foundation depth
- How much of the existing house is opened up
- Glazing: sliding and bifold doors cost more than French doors
Use the guide price tool to see how size and specification change the figure, then ask for a written, itemised quote.
Do you need planning permission for a single-storey extension in Stanley?
The approval route for Stanley is set by planning law in England. In England a single-storey rear extension is often permitted development: broadly up to 3 metres deep on a semi-detached or terraced house and 4 metres on a detached house, no higher than 4 metres, with eaves no higher than 3 metres within 2 metres of a boundary, and covering no more than half the garden. The larger home extension scheme allows up to 6 or 8 metres if you notify the council first and neighbours have a chance to comment. In conservation areas, National Parks and National Landscapes the larger home extension route, side extensions and cladding are not permitted development. Flats and houses whose rights have been removed need a planning application, and listed buildings need listed building consent.
Where work involves a shared wall, building on the boundary, or digging foundations within 3 metres of a neighbour’s building and deeper than its foundations (or within 6 metres for deeper work), the Party Wall etc. Act 1996 applies and notices must be served before work starts.
At the survey we check your house’s planning history and any restrictions, and tell you which route applies.
What we handle
From survey to sign-off, the job normally involves:
- Cavity walls, insulation and roof to current building regulations
- Foundations, drainage and any build-over agreement
- Doors, windows and roof glazing installed
- Building control inspections and completion certificate
- First and second fix electrics, heating and plastering
- Measured survey and design drawings
How long does it take?
Allow 10 to 14 weeks on site for a typical rear extension, after approvals. Before that, surveys, drawings and approvals usually take 6 to 12 weeks, longer if the council asks for changes.
Building in Stanley
The North East has many terraced streets and post-war semis, where rear extensions and loft conversions are popular ways to gain space.
We work across Stanley and neighbouring areas such as Chester-le-Street, Consett and Gateshead. Postcodes we cover in Stanley include DH9.
How it works
- 01
Survey and brief
We visit, discuss your ideas and budget, and survey the property or site at no cost.
- 02
Design and pricing
Design options, then a fixed quote based on the chosen drawings and specification.
- 03
Approvals in place
We handle planning, building control and neighbour notices before work starts.
- 04
Build and sign-off
We run the build to a written programme and hand over the completion certificate.
Questions about single-storey extensions in Stanley
Do I need a party wall agreement?
If you are in England or Wales and the work involves a shared wall, building on the boundary or digging foundations close to a neighbour, the Party Wall etc. Act 1996 applies and notices must be served before work starts. We advise on this at the design stage.
How much does a single-storey extension cost in Stanley?
In Stanley, a single-storey extension typically costs £1,750–£2,600 per m² of floor area, including VAT at 20% (standard rate). A typical 20 m² project comes to roughly £35,000–£52,000. Your fixed price depends on the survey and drawings.
Can I stay in the house during the build?
Usually yes. We build the shell before opening up the back wall, so the house stays weathertight for most of the job. There will be a few weeks when the kitchen or back room is out of use.
What is a build-over agreement?
If a public sewer runs within 3 metres of the extension, the water company normally has to agree to the work before it starts. We check sewer records during design and apply where needed.
Do you build single-storey extensions in Stanley?
Yes. We build single-storey extensions across Stanley, including postcodes DH9. Every project starts with a free home visit.