Double-storey extensions · Farnworth

Double-storey extensions in Farnworth

Our double-storey extensions service covers Farnworth and the rest of Greater Manchester. You get a fixed price in writing for the agreed specification, and one person co-ordinating the trades.

Covering Farnworth

We work in Farnworth (BL4) and the places around it, including Walkden, Bolton and Radcliffe.

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 does a double-storey extension involve?

A double-storey extension adds new rooms on both the ground and first floor in one build, typically a larger kitchen or living space downstairs and an extra bedroom or bathroom above. Because the roof and foundations are shared, the cost per square metre is usually lower than a single-storey extension.

  • Measured survey, design and planning drawings
  • Householder planning application
  • Foundations, steelwork, brick and block walls, roof

What will a double-storey extension cost?

Indicative costs for double-storey extensions. London and the South East usually sit towards the top of each range.

Double-storey extensionsGuide price incl. VAT
Standard specification£2,400 to £2,900 per m²
Good specification£2,900 to £3,400 per m²
High specification£3,400 to £3,850 per m²

Planning and building rules in Farnworth

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.

Two-storey rear extensions can sometimes be permitted development in England (no more than 3 m deep, at least 7 m from the rear boundary, roof pitch to match), but most two-storey and all two-storey side extensions need householder planning permission. Expect around eight weeks for a decision once the application is validated.

What can change the price or programme?

  • The new roof is tied into the old one, so roof tiles and ridge details need to match.
  • The first-floor link can mean moving a bathroom or reshaping the landing.

What are the steps?

  1. Start with a conversation. A short call or the online form is enough for us to understand what you want to build.
  2. Survey at your house. We look at the existing structure, services and access, and agree what the design needs to achieve.
  3. Design and fixed price. You get drawings and a written price for the agreed specification before anything is ordered.
  4. Construction and completion. One site lead co-ordinates every trade through to the building control certificate.

What people ask before starting

Does a two-storey extension need planning permission?

Usually yes. In England some two-storey rear extensions are permitted development, but side extensions over one storey always need planning permission.

Will we need to move out?

Most people stay. The noisiest stage is when we break through into the existing first floor, which we plan for a short window.

How do I get a price for double-storey extensions in Farnworth?

Use the guide price tool for a ballpark figure, then book a visit for a fixed written price for the agreed specification.

Double-storey extensions near Farnworth

Learn more about double-storey extensions, or see every project we cover in Farnworth.

Planning an extension, loft or new home?

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