Allerton, Merseyside
Two-storey rear extension in Allerton
A larger kitchen downstairs and an extra bedroom or bathroom upstairs, under one roof. If you live in Allerton and want to know what a two-storey rear extension would cost and whether it needs planning, start with the online guide price or a free site visit.
We cover Allerton (L18, L19 and L25) as part of our Merseyside work. Two-storey rear extensions suit semi-detached houses in Allerton best, where the extra bedroom matters as much as the bigger kitchen.
Book a free site visit
Tell us about the house and we'll call to arrange a free, no-obligation visit.
How much does a two-storey rear extension cost in Allerton?
Guide prices for a two-storey rear extension in Allerton start from our North West England rate of £1,690–£2,540 per square metre, including VAT. North West prices sit below our West Midlands baseline; access on terraced streets is the main variable.
| Size | Guide price inc VAT |
|---|---|
| 3 m × 5 m footprint, two floors (30 m²) | £51,000–£76,000 |
| 4 m × 6 m footprint, two floors (48 m²) | £81,000–£122,000 |
We put a fixed price in writing once the design is agreed, and explain any provisional sums such as foundations.
Do you need planning permission for a two-storey rear extension in Allerton?
Here is how the rules in England apply to a two-storey rear extension in Allerton.
England's rules allow a rear extension of more than one storey without an application only when it is no deeper than 3 metres and at least 7 metres from the boundary opposite the rear wall, and never on designated land. Most two-storey schemes need householder planning permission.
Conservation areas, National Parks, National Landscapes and the Broads restrict permitted development, and listed buildings always need listed building consent. At the first visit we measure what is there now and tell you which route fits: permitted development, prior approval or a planning application.
What are homes in Allerton like to extend?
Allerton has long runs of terraced houses with back yards and alleys, plus 1930s semis further out. Yard extensions on terraces are often single-storey and close to both boundaries.
How a two-storey rear extension in Allerton comes together
Free site visit
We measure the house and garden, look at the back wall, drainage and boundaries, and talk through what you want from the space.
Design and guide price
Two or three layout options with a guide price for each, so you choose the design knowing what it costs.
Approvals
Permitted development check, prior approval or planning application, then Building Regulations drawings and structural calculations, plus party wall notices where they apply.
Fixed price and build
A written price for the agreed design, a start date and a named contact through the build, ending with the building control completion certificate.
Two-storey rear extensions near Allerton
We also build two-storey rear extensions in nearby Mossley Hill (1.0 miles) and Woolton (1.1 miles).
- Two-storey rear extension in Mossley Hill
- Two-storey rear extension in Woolton
- Two-storey rear extension in Hunts Cross
- Two-storey rear extension in Childwall
- Two-storey rear extension in Belle Vale
Other work in Allerton:
FAQ
Two-storey rear extension questions in Allerton
How much does a two-storey rear extension cost in Allerton?
As a guide, £1,690–£2,540 per square metre including VAT for a standard specification. For example, 3 m × 5 m footprint, two floors (30 m²): about £51,000–£76,000 at that rate. Your written price follows the survey.
Do you handle building control in Allerton?
Yes. We apply to the council or a registered building control approver and hand over the completion certificate.
Is two-storey cheaper per square metre than single-storey?
Usually yes, because the foundations and roof are shared across twice the floor area. The total cost is higher.
Do I need a party wall agreement?
In England, usually yes if the extension is on or near a shared boundary or the foundations are close to a neighbour's building. We serve the notices.
What postcode areas do you cover around Allerton?
Including L18, L19 and L25, and the surrounding Merseyside area.
Can I live at home while the extension is built?
Usually yes. Most of the work is outside until the back wall is opened near the end, and that stage is screened off.