Croxteth, Merseyside
Semi-detached rear extension in Croxteth
Single or two-storey extensions for semi-detached houses, with side access and one party wall. If you live in Croxteth and want to know what a semi-detached rear extension would cost and whether it needs planning, start with the online guide price or a free site visit.
Croxteth and its postcode districts L9, L11 and L12 are part of our Merseyside coverage. Semi-detached houses are common across Merseyside, and their side access makes rear extensions quicker to build.
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 semi-detached rear extension cost in Croxteth?
In Croxteth, our guide for a semi-detached rear extension is £1,790–£2,910 per square metre including VAT for a standard specification. North West prices sit below our West Midlands baseline; access on terraced streets is the main variable.
| Size | Guide price inc VAT |
|---|---|
| 3 m wide × 4 m deep (12 m²) | £21,500–£35,000 |
| 4 m wide × 5 m deep (20 m²) | £35,500–£58,500 |
| 4 m wide × 6 m deep (24 m²) | £43,000–£70,000 |
Ground conditions, glazing, the roof and how far the house is opened up move the final figure within the range.
Do you need planning permission for a semi-detached rear extension in Croxteth?
Here is how the rules in England apply to a semi-detached rear extension in Croxteth.
English permitted development (Class A) allows a single-storey rear extension of 3 metres on a terraced or semi-detached house and 4 metres on a detached one, measured from the original house, with a maximum height of 4 metres and eaves of no more than 3 metres within 2 metres of a boundary.
A two-storey rear extension can be permitted development in England only if it projects no more than 3 metres, stays at least 7 metres from the rear boundary, matches the existing roof pitch and has obscure-glazed upper side windows. In practice most double-storey rear extensions go through a householder planning application.
If 3 or 4 metres is not enough, England's prior approval route allows 6 metres on a terraced or semi-detached house and 8 metres on a detached house for a single-storey rear extension. Neighbours are consulted, the council decides within 42 days, and the fee is £249, rising to £310 from 8 December 2026.
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 Croxteth like to extend?
Stone and brick terraces are common around Croxteth. Where houses back onto a ginnel or alley, deliveries can come in from the rear, which makes the build tidier.
How a semi-detached rear extension in Croxteth comes together
Survey visit
We visit free of charge, measure up, check access, drainage and neighbours' extensions, and note what you want the room to do.
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.
Build and sign-off
We build to the approved drawings with regular updates, then hand over the building control completion certificate and any guarantees from suppliers.
Semi-detached rear extensions near Croxteth
Close by, we work in Norris Green, about 0.8 miles away, and Fazakerley, about 1.2 miles away.
- Semi-detached rear extension in Norris Green
- Semi-detached rear extension in Fazakerley
- Semi-detached rear extension in West Derby
- Semi-detached rear extension in Kirkby
- Semi-detached rear extension in Knotty Ash
Other work in Croxteth:
FAQ
Semi-detached rear extension questions in Croxteth
How much does a semi-detached rear extension cost in Croxteth?
As a guide, £1,790–£2,910 per square metre including VAT for a standard specification. For example, 3 m wide × 4 m deep (12 m²): about £21,500–£35,000 at that rate. Your written price follows the survey.
Is the site visit in Croxteth free?
Yes. We visit, measure up and talk through the options with no cost and no obligation.
How long does a semi extension take?
10 to 16 weeks on site for a single-storey extension.
What postcode areas do you cover around Croxteth?
Including L9, L11 and L12, and the surrounding Merseyside area.
Can you match the brick or stone on my Croxteth house?
We source the closest match and show you samples before ordering; reclaimed materials are often the best match on older houses.
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.