Double-storey extensions · Bletchley

Double-storey extensions in Bletchley

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

Covering Bletchley

Bletchley is about 3 miles south of Milton Keynes. We also cover Milton Keynes (3 miles to the north), Leighton Buzzard and Buckingham.

Homes in the South East

Many South East homes are inter-war or post-war semis and detached houses with room for rear and side extensions, while historic town centres and villages bring conservation area and listed building controls.

What goes into a double-storey extension?

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
  • Structural engineer’s design and calculations
  • Foundations, steelwork, brick and block walls, roof

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

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

Do you need permission for a double-storey extension in Bletchley?

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 Bletchley homeowners check first?

  • 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. 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. We build it. Work follows an agreed programme, with inspections at each stage and a final sign-off.

Your questions answered

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.

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 Bletchley?

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 in nearby towns

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

Planning an extension, loft or new home?

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

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