A single-storey extension is a new ground-floor room built onto your house, usually at the rear or side, with its own foundations, walls and roof, creating a bigger kitchen, living space or bedroom without moving home.
If you have a single-storey extension on your list for a property in Westhoughton, we can help from the first measurements to the final clean-up. For a typical home, plan for 10–16 weeks on site, though larger or more complex jobs take longer. We cover postcodes BL5 and nearby Atherton, Hindley and Tyldesley, and every quote we send is fixed for the scope described in it.
- Guide price
- £33,000–£71,000 inc VAT
- Time on site
- 10–16 weeks on site
- Postcodes
- BL5
- Planning rules
- England
- Local area
- Bolton
- Survey
- Free, with a written quote
How much does a single-storey extension cost in Westhoughton?
Use the table to gauge the cost of a single-storey extension in Westhoughton before we visit. Figures include VAT and are scaled for the North West, coming out about 5% below the national guide, which gives £33,000–£71,000 overall. After a free survey, you receive a fixed written price.
| Type of job | What it usually involves | Guide in Westhoughton |
|---|---|---|
| Small extension (8–12m²) | A modest rear or side extension, such as a utility room or a slightly larger kitchen. | £21,000–£38,000 |
| Typical rear extension (15–25m²) | A kitchen-diner or family room with bifold doors and a rooflight or lantern. | £33,000–£71,000 |
| Large or wrap-around (30m² plus) | A wrap-around or wide rear extension, often with structural steelwork into the house. | £66,000–£124,000 |
What moves the price up or down:
- Floor area, shape and number of corners
- Roof type, rooflights, lanterns and the amount of glazing
- Steelwork needed to open into the existing house
- Finishes, kitchen, flooring and heating specification
What do you get?
- Groundworks, foundations and below-ground drainage
- Steel beams to open into the existing house
- Electrics and plumbing by qualified trades, with certificates
- Windows and external doors, including bifolds if chosen
- Plastering, screed floor and internal doors
- Building control inspections and completion certificate
Homes in Greater Manchester
Rows of Victorian red-brick terraces fill much of Manchester, Salford and the mill towns, with stone terraces in the Pennine fringes around Oldham and Saddleworth. South Manchester has Edwardian semis and villas, Wythenshawe was built as a large interwar garden suburb, and city-centre apartments and new estates continue to grow.
Two-up two-down terraces commonly suit loft conversions, kitchen extensions and kitchen refits. Many need repointing and roof work, while semis in the suburbs often take side extensions, driveways and replacement windows.
Knowing the typical building types in Greater Manchester helps, but a survey of your own home in Westhoughton is what decides the right approach to a single-storey extension.
Planning and building rules in Westhoughton
Planning law differs across the UK. For a home in Westhoughton, it is the England rules below that count, and we check them with the council ahead of any quote.
In England, many single-storey rear extensions are permitted development: typically up to 3 m deep on a semi-detached or terraced house and 4 m on a detached house, no more than 4 m high, and covering no more than half the land around the original house. Larger rear extensions can go through the prior approval process. Side extensions, flats, listed buildings, conservation areas and homes where permitted development rights have been removed need planning permission.
Building Regulations approval is needed for almost every extension, covering foundations, structure, insulation, drainage, ventilation and fire safety. If the work is on or near a shared wall or boundary, the Party Wall etc. Act 1996 may apply.
Rules change and every property is different, so we check the planning history and constraints for your address before we quote.
The four stages
We look at the job
First, someone visits your home in Westhoughton to see the space, take measurements and note anything that could affect the work, such as access or the condition of what is there. There is no charge for this visit.
Your fixed price
You get the price in writing, itemised so you can see where the money goes. As long as the specification stays the same, that is the price you pay for a single-storey extension.
Dates and permissions
Preparation matters as much as the build. We agree access, parking and working hours with you, order materials in good time, and confirm any permissions so the job isn't held up once it starts.
The work itself
On site, the agreed plan is followed and any change is put in writing first. At completion we do a final clean, go through the snagging list with you and leave you with the relevant documents.
Why homeowners choose us
Questions about a single-storey extension in Westhoughton
Do I need planning permission in Westhoughton?
It depends on the work, the size of the project, your property type and whether the building is listed or in a conservation area. Westhoughton is in England, so England's rules apply. Many smaller jobs need no planning application, but some still need building control approval. We check what applies to your address before quoting.
Do you cover Atherton, Hindley and Tyldesley?
Yes. As well as Westhoughton, we cover Atherton, Hindley and Tyldesley and the rest of Greater Manchester. Our coverage is UK-wide, so the process is the same wherever you are: a free site survey, a quote in writing that fixes the price for the agreed scope, and one point of contact while the work is planned and carried out.
What does a typical extension build look like week by week?
A typical single-storey extension follows the same order: clearing the site and digging foundations, building walls up to roof level, then fitting the roof and windows to make it weathertight. Electrics, plumbing, insulation and plastering follow. The last stage is opening into the house, laying the screed and fitting doors and finishes. Building control inspects at key stages, and we book those visits for you.
Is a flat roof or a pitched roof better on an extension?
A flat roof is quicker to build and usually costs less, gives a clean modern look and works well with a roof lantern. A pitched roof matches the main house, sheds water faster and allows a vaulted ceiling, but it costs more and its height can affect neighbours. Modern flat roofs in EPDM rubber or GRP last well when properly detailed. Planning rules on height can also decide the choice.
Do I need an architect for an extension?
You need proper drawings for an extension, but not always a full architect service. A designer or architectural technician can produce planning and building regulations drawings, and a structural engineer provides beam and foundation calculations. If you already have drawings, we price from them. If not, we can arrange the drawings and calculations as part of the project so everything is coordinated from the start.
Also covering areas around Westhoughton
From BL5 to the edges of Westhoughton and on into Atherton, Hindley and Tyldesley, we can arrange a site visit and a written quote for your project, planned around dates that work for you.