Covering Farnworth
Our coverage around Farnworth (BL4) also includes Walkden (2 miles to the south) and Bolton.
Homes in the North West
Terraced housing is a defining feature of many North West towns, which brings party walls and narrow access into most projects, with more space to extend on suburban semis.
What is a single-storey extension?
We design the extension around how you use the house: where the light comes from, how the new room joins the old one, and what happens to the drains and the garden. The structure is built in brick or block to match the house, finished with a flat roof and lantern or a pitched roof, then insulated, plastered and handed back ready to decorate.
- Measured survey and design drawings
- Building control application and inspections
- First-fix and second-fix electrics, plastering and making good
What is the guide price for a single-storey extension in Farnworth?
Typical ranges for single-storey extensions. Ground conditions, access and specification move the final figure, which we fix in writing before work starts.
| Single-storey extensions | Guide price incl. VAT |
|---|---|
| Standard specification | £2,600 to £3,000 per m² |
| Good specification | £3,000 to £3,500 per m² |
| High specification | £3,500 to £4,000 per m² |
What approvals does a single-storey extension need in England?
Projects in England go through two separate checks. Planning (or confirmation that the work is permitted development) comes from the district, borough or unitary council, and building regulations approval comes from the council’s building control team or a registered building control approver. Where work touches a shared wall or digs near a neighbour’s foundations, the Party Wall etc. Act 1996 applies.
In England a single-storey rear extension can often go ahead under permitted development: up to 3 m deep on an attached house or 4 m on a detached one, no higher than 4 m, with eaves no higher than 3 m within 2 m of a boundary.
What should I think about before starting?
- Building on or near a shared boundary usually means serving a party wall notice in England and Wales.
- Large glazed areas need to meet energy rules, which can shape the size of doors and rooflights.
What happens after I enquire?
- Tell us about the project. Call, use the guide price tool or send the form with a few photos and a postcode.
- Free site visit. We measure up, look at access, drains and the structure, and talk through options and budget.
- Drawings, approvals, written quote. We prepare the design, apply for the approvals it needs, and give you a fixed price in writing.
- Construction and completion. One site lead co-ordinates every trade through to the building control certificate.
What people ask before starting
Do I need planning permission for a single-storey extension?
Often not in England, if the extension stays within permitted development limits: 3 m deep on an attached house or 4 m on a detached house, and no higher than 4 m. Larger ones need prior approval or a planning application. Wales, Scotland and Northern Ireland have their own rules.
Can we stay in the house during the build?
Usually yes. We keep the existing house closed off from the works until the knock-through near the end, and agree a temporary kitchen set-up with you if the kitchen is affected.
Can you visit a house in Farnworth to quote?
Yes. After a short call we arrange a site visit to measure up and agree what the design needs to do, then send a written price.
Other towns nearby
- Single-storey extensions in Walkden
- Single-storey extensions in Bolton
- Single-storey extensions in Radcliffe
- Single-storey extensions in Tyldesley
Learn more about single-storey extensions, or see every project we cover in Farnworth.

