Double-storey extensions · King's Lynn

Double-storey extensions in King's Lynn

We take on double-storey extensions in King's Lynn as a complete project: survey, drawings, planning or permitted development checks, building control and the construction itself.

Covering King's Lynn

Alongside King's Lynn, we also cover Wisbech, Swaffham (14 miles to the south-east) and March.

Homes in the East of England

The East of England has a large stock of post-war and modern estate housing alongside period homes in market towns, which makes garage conversions, single-storey extensions and loft conversions popular.

What goes into a double-storey extension?

Two-storey work has to sit comfortably with the house and the neighbours, so most of the design effort goes into the roofline, window positions and how the new first floor connects to the landing. We handle the planning application, the structural design and the building control process, then build, roof and finish both floors.

  • Measured survey, design and planning drawings
  • Foundations, steelwork, brick and block walls, roof
  • Joining the new first floor to the existing landing

How much does a double-storey extension cost in King's Lynn?

Use these ranges to budget for double-storey extensions; the survey turns them into a fixed price for the agreed specification.

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

Do you need permission for a double-storey extension in King's Lynn?

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.

What can affect a double-storey extension?

  • Side extensions close to a boundary are often set back or stepped down so they do not create a terraced effect.
  • The new roof is tied into the old one, so roof tiles and ridge details need to match.

From first call to completion

  1. Tell us about the project. Call, use the guide price tool or send the form with a few photos and a postcode.
  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. Build and hand over. Our teams build to the programme, building control inspects, and you get the completion paperwork at the end.

Questions about a double-storey extension in King's Lynn

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.

Is a two-storey extension better value than a single-storey one?

Per square metre, usually yes, because the foundations and roof serve two floors of space.

Do you work in King's Lynn?

Yes. King's Lynn is within our coverage for double-storey extensions, along with nearby Wisbech and Swaffham.

Other towns nearby

Learn more about double-storey extensions, or see every project we cover in King's Lynn.

Planning an extension, loft or new home?

Get a guide price in two minutes, then book a free site visit.

CallGet a quote