Extensions in Farnworth: design, planning and build
Every type of house extension in Farnworth, from single-storey kitchen extensions to two-storey additions, side returns and orangeries. We design, handle the approvals and build.
- Postcode districtsBL3, BL4, M38
- Price regionNorth West England (×0.95)
- Planning rulesEngland
- Site visitFree, no obligation
Popular extension prices in Farnworth
We publish guide prices so you can budget before anyone visits. For Farnworth they are adjusted by ×0.95, the factor we use across North West England.
| Extension type | Example size | Standard spec (inc VAT) |
|---|---|---|
| Orangery extensions | 16 m² | £42,500 – £53,500 |
| Side return extensions | 11 m² | £25,000 – £31,500 |
| Single-storey rear extensions | 20 m² | £38,500 – £49,500 |
| Double-storey extensions | 32 m² | £54,500 – £71,500 |
| Kitchen extensions | 20 m² | £39,500 – £50,500 |
Areas we cover around Farnworth
Across BL3, BL4, M38, we can visit, measure and advise. Neighbouring towns we cover include Walkden (2 miles), Bolton (3 miles), Radcliffe (3 miles), Tyldesley (4 miles), Swinton (4 miles). For homes towards Merseyside, Golborne is around 10 miles away.
What works best for Farnworth houses?
The North West has a high share of Victorian and Edwardian terraces with rear yards and outriggers, plus large areas of inter-war semis in the suburbs.
Start by comparing side return extensions, single-storey rear extensions and kitchen extensions: between them they cover most of the layouts we see requested for houses like these.
Planning and building control in Farnworth
In England a single-storey rear extension can usually go up to 3 m beyond the original rear wall of a semi-detached or terraced house, or 4 m on a detached house, without a planning application, provided it is no more than 4 m high, keeps eaves to 3 m within 2 m of a boundary and, with other buildings, covers no more than half the land around the original house. The larger home extension prior approval scheme raises those depths to 6 m and 8 m, with neighbours notified and a 42-day decision.
In England a single-storey side extension can be permitted development if it is no more than 4 m high and no wider than half the width of the original house. Two-storey side extensions, and any side extension on designated land such as a conservation area, need a householder planning application.
In a conservation area, national park, National Landscape, the Broads or a World Heritage Site the permitted development limits are tighter (no side or two-storey extensions without an application). Listed homes need listed building consent, and if permitted development rights have been removed, any extension needs an application.
If the work involves a shared wall, building on the boundary, or digging foundations within 3 m (sometimes 6 m) of a neighbour's building, the Party Wall etc. Act 1996 applies and notice must be served before work starts: two months for work to a party wall, one month for new walls on the boundary and for excavations.
Applications are decided by the local planning authority (your district, borough or unitary council).
Choose an extension type
- Side extensions · from £20,500
- Double-storey extensions · from £36,000
- Porch extensions · from £3,800
- Planning permission for extensions · from £300
- Building regulations for extensions · from £850
- Annexe extensions · from £52,000
- Extensions over a garage · from £22,500
- Timber frame extensions · from £19,500
- Utility and boot room extensions · from £13,000
- Orangery extensions · from £28,500
- Pitched roof extensions · from £21,000
- Wraparound extensions · from £34,000
- Home office extensions · from £15,000
- Bungalow extensions · from £24,500
- Kitchen extensions · from £25,500
- Bedroom extensions · from £24,500
- Side return extensions · from £17,000
- Flat roof extensions · from £19,500
- Conservatory replacement extensions · from £19,000
- Glass box extensions · from £28,500
- Single-storey rear extensions · from £19,500
- Extension plans and drawings · from £1,100
Free site visit
It starts with a visit to your house to measure, check access and talk through ideas and budget.
Design and approvals
We produce the drawings and structural design, and manage the approvals so they are in place before work starts.
Fixed written price
With the design and specification agreed, you get a fixed written price and a start date.
Build and sign-off
We build it with one project manager, book the building control inspections and hand over the completion certificate.
Questions about extensions in Farnworth
How much does an extension cost in Farnworth?
Using our North West England factor (×0.95), a standard-spec single-storey extension of 20 m² is a guide £38,500 to £49,500 including VAT, and a 32 m² two-storey extension £54,500 to £71,500. Your written price follows the survey.
Do you cover all of Farnworth?
Yes, including the surrounding parts of Greater Manchester. Site visits are free and there is no obligation.
Do I need planning permission for an extension in Farnworth?
Not always. It depends on the size, position and your property's history. Many single-storey rear extensions in England are permitted development or can use prior approval.
How long does an extension take in Farnworth?
Usually 2 to 4 months of design and approvals, then 10 to 16 weeks on site for a single-storey extension or 16 to 24 weeks for two storeys.
Can I get a price before anyone visits?
Yes. This page shows guide prices adjusted for Farnworth, and the guide-price tool gives a range for your own size and finish in about a minute.
Book a free site visit in Farnworth
We will measure up, check the planning position and give you honest guide figures.
- Free, no-obligation site visit
- Planning route checked before you spend on drawings
- Written price once the design is agreed
- Building control sign-off at the end
Prefer to talk? Call 0800 088 6341 or .
Book a free site visit
Tell us a little about the project and we will arrange a time.