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Extension plans and drawings in Farnworth

For Farnworth homeowners we handle extension plans and drawings, with fees agreed in writing before any work starts.

  • Guide price in FarnworthFrom £1,100 inc VAT
  • PlanningWe find the right route for you
  • Timescale2–6 weeks for drawings
  • Postcode districtsBL3, BL4, M38
Extension floor plans and elevations with a scale ruler and laser measure

Planning rules that apply in Farnworth

In England the main routes are permitted development (ideally confirmed with a lawful development certificate, £274), larger home extension prior approval (£249, 42 days) and a householder planning application (£548, normally 8 weeks), with council fees as set from 1 April 2026.

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.

Building over or within 3 m of a public sewer needs the water company's consent, usually through a build-over agreement, before the foundations go in.

Applications are decided by the local planning authority (your district, borough or unitary council).

Fees in Farnworth

These are guide fees for Farnworth, adjusted for North West England (×0.95) and including VAT. Council application and inspection fees are paid separately.

OptionWhat it coversGuide price
EssentialMeasured survey and planning drawings£1,100 – £2,100
StandardPlanning drawings plus building regulations drawings£2,050 – £3,650
PremiumFull pack with structural calculations and 3D visuals£3,200 – £5,250

Try the guide-price tool to see a range for your own size and finish.

Who this service is for

  • Projects that need a planning application or other approval
  • Anyone who wants fixed designs before getting build prices
  • Homeowners at the very start of a project

The most expensive changes are the ones made after the steel is ordered. A good design stage settles layout, heights, glazing and services on paper, so the build price is firm.

Local to Farnworth

Our survey diary covers Farnworth, including BL3, BL4, M38. The same team covers Walkden (2 miles), Bolton (3 miles), Radcliffe (3 miles), Tyldesley (4 miles), all within easy reach.

For homes towards Merseyside, Golborne is around 10 miles away. Across the North West, terraced houses with small rear yards suit compact rear and side return extensions, while suburban semis have room for more.

What happens next

Site visits are free and there is no obligation. Where drawings are needed, the design stage is priced in writing before it starts.

  1. Free site visit

    It starts with a visit to your house to measure, check access and talk through ideas and budget.

  2. Design and approvals

    We draw the design, agree it with you and handle planning or permitted development checks and building regulations.

  3. Fixed written price

    You receive a written, itemised price and programme. Nothing starts until you are happy with it.

  4. Build and sign-off

    The build is managed from start to finish, inspected at each stage and signed off on completion.

Questions answered

How long does this take for a Farnworth home?

2–6 weeks for drawings, depending on the council and the complexity of the project.

Can I see a price before committing to anything?

Yes. The guide prices on this page are adjusted for Farnworth, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.

Will my neighbours in Farnworth be involved?

If a planning application or prior approval is needed, the council notifies neighbours. If the work is on or near a shared boundary, party wall notices may also be needed.

How much do extension plans cost?

Our design packs range from about £1,100 to £5,250 including VAT, from planning drawings only to a full pack with building regulations drawings, structural calculations and 3D views. Council fees are separate.

Do I need an architect?

Not necessarily. For most extensions an experienced designer or architectural technologist is enough. For listed buildings or complex sites an architect’s input can help.

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

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