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 South Yorkshire?
In South Yorkshire, a single-storey extension typically costs £1,800–£2,700 per m² of floor area, including VAT at 20% (standard rate). For a typical 20 m² project that is roughly £36,000–£54,000. We start from a UK-wide guide and adjust it for Yorkshire and the Humber, where labour and materials are typically about 7% below average. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (14 m²) | £25,000–£38,000 |
| Typical project (20 m²) | £36,000–£54,000 |
| Larger project (28 m²) | £50,500–£75,500 |
| Rate per m² | £1,800–£2,700 |
What moves the price most:
- Roof type and the size of any lantern or roof windows
- Glazing: sliding and bifold doors cost more than French doors
- Floor area and the length of new wall
- Ground conditions and foundation depth
For a figure based on your own measurements, try the guide price tool, then book a free home visit for a fixed quote.
Do you need planning permission for a single-storey extension in South Yorkshire?
Before anything is built in South Yorkshire, 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.
Our first visit includes a check of your planning history, so you know the route before paying for drawings.
What we handle
What we take care of:
- Foundations, drainage and any build-over agreement
- Measured survey and design drawings
- Structural calculations for steels and lintels
- First and second fix electrics, heating and plastering
- Knock-through to the existing house with steel beams
- Doors, windows and roof glazing installed
How long does it take?
Build time is typically 10 to 14 weeks on site for a typical rear extension, after approvals. Design and approvals come first and typically take 6 to 12 weeks, depending on the approval route.
Building in South Yorkshire
Yorkshire and the Humber has stone and brick terraces as well as inter-war and newer estates, so materials matching is an early design question.
Towns we cover in South Yorkshire include Sheffield, Rotherham, Doncaster, Barnsley, Bentley and Chapeltown.
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 South Yorkshire
Is VAT charged on an extension?
Yes. Building work on an existing home is standard-rated, so VAT at 20% applies. Our guide prices include it.
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.
Do you build single-storey extensions in South Yorkshire?
Yes. We build single-storey extensions across South Yorkshire, including postcodes DN1, DN10, DN11, DN12 and DN14. Every project starts with a free home visit.
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.
How much does a single-storey extension cost in South Yorkshire?
In South Yorkshire, a single-storey extension typically costs £1,800–£2,700 per m² of floor area, including VAT at 20% (standard rate). A typical 20 m² project comes to roughly £36,000–£54,000. Your fixed price depends on the survey and drawings.