A double-storey extension adds two floors of new space to your house in one build, typically a larger kitchen or living room downstairs with an extra bedroom, bathroom or en-suite above, sharing one set of foundations and one roof.
Whatever prompted you to look into a double-storey extension, whether wear and tear, a growing family or plans to move, we can survey your Prescot home and give you a price in writing. Homes in the North West typically come in at £57,000–£114,000, VAT included, for this kind of work. We also cover Huyton, St Helens and Halewood, and the same steps apply wherever you are in Merseyside.
- Guide price
- £57,000–£114,000 inc VAT
- Time on site
- 14–22 weeks on site
- Postcodes
- L34, L35 and L36
- Planning rules
- England
- Local area
- Knowsley
- Survey
- Free, with a written quote
What should you budget for a double-storey extension in Prescot?
The costs listed here are typical for a double-storey extension around Prescot and include VAT. They reflect labour and material costs in the North West, about 5% below the national guide, giving a range of £57,000–£114,000. Exact pricing depends on your home, so we only fix it once a free site survey is done.
| Type of job | What it usually involves | Guide in Prescot |
|---|---|---|
| Small (15–20m² total) | A compact rear or side extension adding a small room on each floor. | £38,000–£62,000 |
| Typical (30–40m² total) | A larger kitchen or living room below with a double bedroom or en-suite above. | £57,000–£114,000 |
| Large (50m² plus total) | Wide or deep extensions, often with a new bathroom, steelwork and high-spec glazing. | £95,000–£171,000 |
What moves the price up or down:
- Combined floor area across both storeys
- Bathrooms, en-suites and plumbing on the upper floor
- Foundation depth, ground conditions and drains to divert
- Scaffolding duration, access and the level of finishes
Scope of the work
- Groundworks, foundations and below-ground drainage
- First-floor joists, stud walls and new openings upstairs
- Roof structure tied into the existing roof, tiled to match
- Scaffolding for the full build, erected and inspected
- Electrics, plumbing and heating by qualified trades, with certificates
- Windows, external doors, plastering and internal doors
Homes in Merseyside
Liverpool's housing includes Georgian terraces near the centre, large areas of Victorian red-brick terraces, Edwardian semis in the suburbs and big interwar council estates. The Wirral has Victorian villas and interwar semis, Southport has Victorian villas and bungalows, and St Helens and Knowsley have post-war estates and newer housing.
Coastal areas on the Wirral and Sefton coast are exposed to salt and wind, and the region gets frequent rain off the Irish Sea.
Building traditions across Merseyside also raise conservation and planning questions, so we check those for a double-storey extension in Prescot at the survey stage.
Do you need permission in Prescot?
Which rules apply depends on where you live. For Prescot, the answer is England, and the points below reflect that; we verify them with the council before quoting.
In England, a two-storey rear extension can only be permitted development if it is no more than 3 m deep, at least 7 m from the rear boundary and finished to match the house. Most double-storey and all two-storey side extensions need full planning permission.
Building Regulations approval is needed, with structural calculations for beams, foundations and the roof. The Party Wall etc. Act 1996 often applies on semi-detached and terraced houses.
Rules change and every property is different, so we check the planning history and constraints for your address before we quote.
What happens after you get in touch?
Free site survey
First, someone visits your home in Prescot 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.
Quote in writing
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 double-storey extension.
Getting ready
Next comes planning the work itself. We set a start date that suits you, line up the right trades, and make sure any approvals for a double-storey extension are in place before the first day on site.
The work itself
The work is carried out to the agreed specification, with floors and furniture protected and the site kept tidy. At the end we clean up, walk through the finished job with you and hand over any certificates.
What you can expect from us
Common questions
Do you cover Huyton, St Helens and Halewood?
Yes. As well as Prescot, we cover Huyton, St Helens and Halewood and the rest of Merseyside. 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.
How is the new roof joined to the existing house?
The new roof is usually tied into the existing roof so the two read as one. On a rear extension this often means a lower ridge or a hipped end, with valleys where the slopes meet. We strip back some existing tiles, fix new rafters and battens, and lay matching tiles or slates. Lead or proprietary flashings seal the junctions so water runs off properly.
Do I need planning permission for a two-storey extension?
Most two-storey extensions need planning permission, but it depends on the size, height and position, your home's location, whether it is listed or in a conservation area, and which UK nation you are in. In England, a two-storey rear extension can sometimes be built under permitted development if it is no deeper than 3m and at least 7m from the rear boundary. We check what applies before quoting.
Can the new upstairs room have its own bathroom?
A new upstairs room can usually have an en-suite, provided waste pipes can reach the soil stack or a new one can be installed. Running the waste pipe to the right falls is the main design question, and a pumped system is an option where gravity will not work. We plan bathroom positions at the design stage so pipes, ventilation and insulation are built in rather than added later.
How much will a double-storey extension cost in Prescot?
As a guide, expect to pay £57,000–£114,000 including VAT for a double-storey extension in Prescot. That range is adjusted for the North West, which runs about 5% below the national guide. Where your project lands depends on size, materials, access and the condition of what is already there. We confirm a fixed price in writing after a free survey of your home.
Near Prescot
Addresses in L34, L35 and L36 are all covered for Prescot, along with Huyton, St Helens and Halewood close by. Give us your postcode when you get in touch and we will confirm the details.