Double-storey extensions · Oxford

Double-storey extensions in Oxford

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

Covering Oxford

Alongside Oxford, we also cover Abingdon (6 miles to the south), Didcot and Witney.

Homes in the South East

The South East has a lot of 1930s and post-war semi-detached housing, well suited to rear extensions and hip-to-gable loft conversions, alongside period properties in conservation areas that need a more careful design.

What is included in a double-storey extension in Oxford?

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.

  • Householder planning application
  • Windows, insulation, plastering, electrics and plumbing
  • Joining the new first floor to the existing landing

How much does a double-storey extension cost in Oxford?

What double-storey extensions typically cost. These are guide ranges; the written quote for your house replaces them.

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 Oxford?

English projects need planning clearance from the local council, building regulations sign-off from building control, and party wall notices where the work is on or near a shared boundary. We prepare and manage all three.

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 should I think about before starting?

  • 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.

What happens after I enquire?

  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. Construction and completion. One site lead co-ordinates every trade through to the building control certificate.

Double-storey extensions: common questions

How much does a two-storey extension cost?

Typically about £2,400 to £3,850 per square metre of new floor area including VAT. A 40 m² extension across two floors is often around £100,000 to £150,000 depending on specification.

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.

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

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

Other towns nearby

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

Planning an extension, loft or new home?

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