Walkden, Greater Manchester
Semi-detached rear extension in Walkden
Semi-detached rear extension in Walkden: single or two-storey extensions for semi-detached houses, with side access and one party wall. We measure the house, show you what the rules allow, price it in writing and build it.
Walkden and its postcode districts M28 and M38 are part of our Greater Manchester coverage. In Walkden 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 Walkden?
A semi-detached rear extension in Walkden 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 Walkden?
Here is how the rules in England apply to a semi-detached rear extension in Walkden.
Under England's householder permitted development rules you can usually add 3 metres at the back of an attached house, or 4 metres on a detached house, without a planning application, as long as the extension stays under 4 metres high and its eaves stay under 3 metres where it is 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.
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. We check your house's planning history and any conservation area before drawing, so the route is clear before you spend on plans.
What are homes in Walkden like to extend?
Walkden 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 semi-detached rear extension in Walkden 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.
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 Walkden
We also build rear extensions for semi-detached houses in nearby Kearsley (1.3 miles) and Little Hulton (1.3 miles).
- Semi-detached rear extension in Kearsley
- Semi-detached rear extension in Little Hulton
- Semi-detached rear extension in Farnworth
- Semi-detached rear extension in Swinton
- Semi-detached rear extension in Tyldesley
Other work in Walkden:
FAQ
Semi-detached rear extension questions in Walkden
What postcode areas do you cover around Walkden?
Including M28 and M38, and the surrounding Greater Manchester area.
Will I need a structural engineer?
Yes for the beam over the new opening and usually the foundations; we arrange them and their calculations go to building control.
How far can I extend a semi without planning?
3 metres under permitted development in England, or up to 6 metres with prior approval, outside designated land.
How much does a semi-detached rear extension cost in Walkden?
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.
Can you match the brick or stone on my Walkden 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.