Covering St Helens
We work in St Helens (WA10) and the places around it, including Prescot, Ashton-in-Makerfield and Huyton.
Homes in the North West
The North West has long rows of Victorian terraced houses in its towns and cities, alongside inter-war semis and post-war estates, so rear extensions, dormer lofts and kitchen extensions are common projects.
What does a single-storey extension involve?
A single-storey extension adds one level of new floor space to the back or side of a house, usually to open up a kitchen, dining or family room. It is the most common way to gain space without moving, and many can be built without a planning application.
- Measured survey and design drawings
- Building control application and inspections
- Foundations, drainage and structural steel
How much does a single-storey extension cost in St Helens?
Typical ranges for single-storey extensions. Ground conditions, access and specification move the final figure, which we fix in writing before work starts.
| Single-storey extensions | Guide price incl. VAT |
|---|---|
| Standard specification | £2,600 to £3,000 per m² |
| Good specification | £3,000 to £3,500 per m² |
| High specification | £3,500 to £4,000 per m² |
How is a single-storey extension approved in St Helens?
In England we deal with the council’s planning team for permission or a lawful development certificate, with building control (the council or a registered building control approver) for inspections, and with neighbours under the Party Wall etc. Act 1996 where it applies.
In England a single-storey rear extension can often go ahead under permitted development: up to 3 m deep on an attached house or 4 m on a detached one, no higher than 4 m, with eaves no higher than 3 m within 2 m of a boundary. Deeper extensions, up to 6 m or 8 m, need prior approval from the council first.
What should I think about before starting?
- Drains under the footprint may need diverting or a build-over agreement with the water company.
- Large glazed areas need to meet energy rules, which can shape the size of doors and rooflights.
From first call to completion
- Send us the details. Give us a postcode, a rough idea of size and some photos, by phone, form or the guide price tool.
- Free site visit. We measure up, look at access, drains and the structure, and talk through options and budget.
- Design and fixed price. You get drawings and a written price for the agreed specification before anything is ordered.
- Construction and completion. One site lead co-ordinates every trade through to the building control certificate.
Questions about a single-storey extension in St Helens
Can we stay in the house during the build?
Usually yes. We keep the existing house closed off from the works until the knock-through near the end, and agree a temporary kitchen set-up with you if the kitchen is affected.
Will the brick match?
We source the closest available match for colour, size and texture and agree a sample panel with you before laying.
How do I get a price for single-storey extensions in St Helens?
Use the guide price tool for a ballpark figure, then book a visit for a fixed written price for the agreed specification.
Single-storey extensions near St Helens
- Single-storey extensions in Prescot
- Single-storey extensions in Ashton-in-Makerfield
- Single-storey extensions in Huyton
- Single-storey extensions in Newton-le-Willows
Learn more about single-storey extensions, or see every project we cover in St Helens.

