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 extensions | Guide 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?
- Start with a conversation. A short call or the online form is enough for us to understand what you want to build.
- Survey at your house. We look at the existing structure, services and access, and agree what the design needs to achieve.
- Design and fixed price. You get drawings and a written price for the agreed specification before anything is ordered.
- 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
- Double-storey extensions in Milton Keynes
- Double-storey extensions in Leighton Buzzard
- Double-storey extensions in Buckingham
- Double-storey extensions in Dunstable
Learn more about double-storey extensions, or see every project we cover in Bletchley.

