Burnley, Lancashire
Semi-detached rear extension in Burnley
Thinking about a semi-detached rear extension in Burnley? Single or two-storey extensions for semi-detached houses, with side access and one party wall. Our team handles the drawings, the planning route and the build, and your contract is with one company throughout.
Burnley is covered from our Lancashire round, including BB10 and BB11. In Burnley 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 Burnley?
In Burnley, 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 Burnley?
The planning route for a semi-detached rear extension in Burnley is set by England's householder rules and your council.
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.
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 Burnley like to extend?
Stone and brick terraces are common around Burnley. 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 Burnley 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.
Written price, then build
Once the design and approvals are in place, you get a fixed written price and programme, and we build through to sign-off.
Semi-detached rear extensions near Burnley
We also build rear extensions for semi-detached houses in nearby Brierfield (1.7 miles) and Nelson (2.7 miles).
- Semi-detached rear extension in Brierfield
- Semi-detached rear extension in Nelson
- Semi-detached rear extension in Padiham
- Semi-detached rear extension in Colne
- Semi-detached rear extension in Accrington
Other work in Burnley:
FAQ
Semi-detached rear extension questions in Burnley
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 much does a semi-detached rear extension cost in Burnley?
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.
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 long does a rear extension take to build in Burnley?
Most single-storey rear extensions take 10 to 16 weeks on site and two-storey extensions 16 to 26 weeks, after design and approvals.
What postcode areas do you cover around Burnley?
Including BB10 and BB11, and the surrounding Lancashire area.
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.