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 Leeds?
In Leeds, 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. Building costs in Yorkshire and the Humber run about 7% below the UK average, and the figures for Leeds are adjusted to reflect that. 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 |
Your quote will depend mainly on:
- 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
- Floor area and the length of new wall
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 Leeds?
Whether you need planning permission depends on your house and its location 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
Handled as part of most single-storey extensions:
- Foundations, drainage and any build-over agreement
- Structural calculations for steels and lintels
- Doors, windows and roof glazing installed
- Knock-through to the existing house with steel beams
- Building control inspections and completion certificate
- First and second fix electrics, heating and plastering
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 Leeds
In Yorkshire, through-terraces and back-to-backs have particular constraints, while semis and detached houses suit larger extensions.
Projects in Leeds (LS1, LS2, LS3 and LS4) are surveyed in person before we quote, so the price reflects your actual property.
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 fixed quote
Drawings, structural calculations and an itemised, fixed price for the agreed specification.
- 03
Permissions sorted
Applications, building control and neighbour arrangements, all before the start date.
- 04
Build and handover
Work follows the agreed programme, with inspections along the way and a completion certificate at the end.
Questions about single-storey extensions in Leeds
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.
How much does a single-storey extension cost in Leeds?
In Leeds, 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.
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.
Who approves a single-storey extension in Leeds?
Planning matters in Leeds go to the council covering your address, and the work needs building control approval. We prepare and submit the applications for you.
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.