Farnworth, Greater Manchester
Single-storey rear extension in Farnworth
Ground-floor space across the back of the house, usually for a kitchen, dining or family room. We design, get the approvals for and build single-storey rear extensions in Farnworth and the surrounding area, with one contract from the first survey to building control sign-off.
Farnworth sits in Greater Manchester, with postcode districts including BL2, BL3 and BL4. A depth of 3 to 4 metres keeps many single-storey rear extensions in Farnworth within permitted development, subject to the house's planning history.
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 single-storey rear extension cost in Farnworth?
In Farnworth, our guide for a single-storey 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 |
Your written price follows a measured survey and an agreed design, so it reflects your house, not an average.
Do you need planning permission for a single-storey rear extension in Farnworth?
Planning for a single-storey rear extension in Farnworth 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.
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. Before any drawing we look up the property's history with the council, because earlier extensions and removed rights change the answer.
What are homes in Farnworth like to extend?
Farnworth 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 single-storey rear extension in Farnworth comes together
Look round and measure
A free visit to see the back of the house, measure it, check the drains and boundaries and hear what you need.
Options and costs
We draw layout options and price each one, so the budget shapes the design rather than surprising you later.
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.
Single-storey rear extensions near Farnworth
We also build single-storey rear extensions in nearby Little Lever (1.3 miles) and Kearsley (1.3 miles).
- Single-storey rear extension in Little Lever
- Single-storey rear extension in Kearsley
- Single-storey rear extension in Little Hulton
- Single-storey rear extension in Walkden
- Single-storey rear extension in Bolton
Other work in Farnworth:
FAQ
Single-storey rear extension questions in Farnworth
Do I need planning permission for a rear extension in Farnworth?
Often not for a single-storey rear extension of up to 3 metres (4 metres on a detached house) under permitted development, or up to 6 or 8 metres with prior approval, unless the house is in a conservation area or its rights have been removed.
Do you handle building control in Farnworth?
Yes. We apply to the council or a registered building control approver and hand over the completion certificate.
How deep can a single-storey rear extension be without planning?
In England, 3 metres on an attached house and 4 metres on a detached house under permitted development, or up to 6 and 8 metres with prior approval. Wales allows 4 metres; Scotland and Northern Ireland have their own limits.
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.
Who will build my extension?
Vetted building teams working under contract to us. Your contract is with S&K Property Investments and Improvement Ltd for the design and the build.
Can you match the brick or stone on my Farnworth house?
We source the closest match and show you samples before ordering; reclaimed materials are often the best match on older houses.