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 Heswall?
In Heswall, 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:
- Ground conditions and foundation depth
- Roof type and the size of any lantern or roof windows
- Kitchen, flooring and finishes, which we can include or leave to you
- 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 Heswall?
Approvals for a single-storey extension in Heswall 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:
- Cavity walls, insulation and roof to current building regulations
- First and second fix electrics, heating and plastering
- Building control inspections and completion certificate
- Measured survey and design drawings
- Knock-through to the existing house with steel beams
- Doors, windows and roof glazing installed
How long does it take?
Allow 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 Heswall
The North West has many brick terraces and inter-war semis, where kitchen extensions and dormer loft conversions add space without moving.
Our Heswall coverage includes postcode districts CH60, and we also work in nearby places such as Bebington, Birkenhead and Wallasey.
How it works
- 01
Free visit
We look at the property, talk through what you want and measure up. There is no charge and no obligation.
- 02
Design and fixed quote
Drawings, structural calculations and an itemised, fixed price for the agreed specification.
- 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 Heswall
How long does a single-storey extension take in Heswall?
Typically 10 to 14 weeks on site for a typical rear extension, after approvals. Design and approvals beforehand usually take 6 to 12 weeks.
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.
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.
How much does a single-storey extension cost in Heswall?
In Heswall, 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 planning permission for a single-storey extension?
Not always. Many small rear extensions are permitted development, within limits on depth, height and how much of the garden is covered. The limits depend on which nation you live in and on protected areas such as conservation areas, and flats or houses whose rights have been removed need an application. We check this at the survey and can apply to the council for formal confirmation.