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 Stockton-on-Tees?
In Stockton-on-Tees, 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. Building costs in the North East run about 10% below the UK average, and the figures for Stockton-on-Tees are adjusted to reflect that. 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 |
Your quote will depend mainly on:
- Glazing: sliding and bifold doors cost more than French doors
- How much of the existing house is opened up
- Kitchen, flooring and finishes, which we can include or leave to you
- Roof type and the size of any lantern or roof windows
A guide range is only a starting point: the guide price tool gives an instant figure for your size, and a free survey turns it into a fixed quote.
Do you need planning permission for a single-storey extension in Stockton-on-Tees?
Before anything is built in Stockton-on-Tees, we confirm which approvals apply 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.
If the answer is not clear-cut, we can apply for formal confirmation before you commit to the build.
What we handle
From survey to sign-off, the job normally involves:
- Measured survey and design drawings
- Structural calculations for steels and lintels
- Knock-through to the existing house with steel beams
- Foundations, drainage and any build-over agreement
- Doors, windows and roof glazing installed
- Cavity walls, insulation and roof to current building regulations
How long does it take?
The build itself usually takes 10 to 14 weeks on site for a typical rear extension, after approvals. Allow time beforehand for drawings and approvals, usually 6 to 12 weeks.
Building in Stockton-on-Tees
Across the North East, colliery-era terraces and newer estates sit side by side, so the right project depends on the house type.
Stockton-on-Tees sits in County Durham, about 18 miles south-east of Durham. We cover the whole of Stockton-on-Tees, including postcodes TS19.
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
Permissions sorted
Applications, building control and neighbour arrangements, all before the start date.
- 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 Stockton-on-Tees
How much does a single-storey extension cost in Stockton-on-Tees?
In Stockton-on-Tees, 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.
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 Stockton-on-Tees?
Yes. We build single-storey extensions across Stockton-on-Tees, including postcodes TS19. Every project starts with a free home visit.
How long does a single-storey extension take?
Once approvals are in place, a typical rear extension takes 10 to 14 weeks on site. Design and approvals usually take another 6 to 12 weeks beforehand, depending on whether a planning application is needed.
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.