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 Chester?
In Chester, a single-storey extension typically costs £1,850–£2,750 per m² of floor area, including VAT at 20% (standard rate). For a typical 20 m² project that is roughly £37,000–£55,000. We start from a UK-wide guide and adjust it for the North West, where labour and materials are typically about 6% below average. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (14 m²) | £26,000–£38,500 |
| Typical project (20 m²) | £37,000–£55,000 |
| Larger project (28 m²) | £52,000–£77,000 |
| Rate per m² | £1,850–£2,750 |
Your quote will depend mainly on:
- How much of the existing house is opened up
- Ground conditions and foundation depth
- Glazing: sliding and bifold doors cost more than French doors
- Kitchen, flooring and finishes, which we can include or leave to you
Your exact price depends on the survey and drawings. The guide price tool gives a quick range in the meantime.
Do you need planning permission for a single-storey extension in Chester?
Approvals for a single-storey extension in Chester follow the rules for 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
The work we manage on a single-storey extension:
- First and second fix electrics, heating and plastering
- Building control inspections and completion certificate
- Foundations, drainage and any build-over agreement
- Measured survey and design drawings
- Doors, windows and roof glazing installed
- Cavity walls, insulation and roof to current building regulations
How long does it take?
Allow 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 Chester
The North West has many brick terraces and inter-war semis, where kitchen extensions and dormer loft conversions add space without moving.
Projects in Chester (CH1) 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
Drawings and written quote
We prepare the design and give you a written, itemised quote with inclusions and exclusions.
- 03
Approvals
Planning or permitted development confirmation, building regulations and any party wall matters.
- 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 Chester
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.
Who approves a single-storey extension in Chester?
Planning matters in Chester go to the council covering your address, and the work needs building control approval. We prepare and submit the applications for you.
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 Chester?
In Chester, a single-storey extension typically costs £1,850–£2,750 per m² of floor area, including VAT at 20% (standard rate). A typical 20 m² project comes to roughly £37,000–£55,000. Your fixed price depends on the survey and drawings.
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.