Warrington, Cheshire
Semi-detached rear extension in Warrington
Single or two-storey extensions for semi-detached houses, with side access and one party wall. If you live in Warrington 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.
Warrington is covered from our Cheshire round, including WA1, WA2, WA4 and WA5. In Warrington we measure the attached neighbour's extension at the survey, because it often sets the sensible depth for yours.
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 Warrington?
A semi-detached rear extension in Warrington is priced at £1,790–£2,910 per square metre including VAT as a guide, before kitchen fit-out and fees. 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 Warrington?
Planning for a semi-detached rear extension in Warrington follows the English householder rules.
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.
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.
England also has the larger home extension route: a single-storey rear extension of up to 6 metres on an attached house or 8 metres on a detached house, after prior approval from the council. The council notifies your neighbours and has 42 days to decide; the fee is £249 (£310 for applications made from 8 December 2026). The route is not available on designated land such as conservation areas.
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 Warrington like to extend?
Stone and brick terraces are common around Warrington. 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 Warrington 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.
Drawings and budget
Floor plans and elevations for the options, each with a guide price.
Planning and regulations
We take the design through the right planning route, then produce the construction drawings and engineer's calculations for building control.
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.
Semi-detached rear extensions near Warrington
From Warrington, the nearest places we also cover are Great Sankey (2.5 miles) and Newton-le-Willows (4.1 miles).
- Semi-detached rear extension in Great Sankey
- Semi-detached rear extension in Newton-le-Willows
- Semi-detached rear extension in Lymm
- Semi-detached rear extension in Golborne
- Semi-detached rear extension in Haydock
Other work in Warrington:
FAQ
Semi-detached rear extension questions in Warrington
What postcode areas do you cover around Warrington?
Including WA1, WA2, WA4 and WA5, and the surrounding Cheshire area.
Is the site visit in Warrington free?
Yes. We visit, measure up and talk through the options with no cost and no obligation.
Can I match pebbledash or render?
Yes. Many semis are refinished with new render across the whole back elevation so old and new match.
How long does a rear extension take to build in Warrington?
Most single-storey rear extensions take 10 to 16 weeks on site and two-storey extensions 16 to 26 weeks, after design and approvals.
How much does a semi-detached rear extension cost in Warrington?
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.
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.