Covering Brighton
Our coverage around Brighton (BN2) also includes Hove, Rottingdean and Burgess Hill.
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 is included in a double-storey extension in Brighton?
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 Brighton?
What double-storey extensions typically cost. These are guide ranges; the written quote for your house replaces them.
| 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 Brighton?
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.
- Neighbours’ light is assessed using the 45-degree guide many councils use.
What are the steps?
- Tell us about the project. Call, use the guide price tool or send the form with a few photos and a postcode.
- Free site visit. We measure up, look at access, drains and the structure, and talk through options and budget.
- Drawings, approvals, written quote. We prepare the design, apply for the approvals it needs, and give you a fixed price in writing.
- We build it. Work follows an agreed programme, with inspections at each stage and a final sign-off.
Questions about a double-storey extension in Brighton
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.
How long does a two-storey extension take?
Around 14 to 24 weeks on site, plus the planning period before that.
Do you work in Brighton?
Yes. Brighton is within our coverage for double-storey extensions, along with nearby Hove and Rottingdean.
Also covering
- Double-storey extensions in Hove
- Double-storey extensions in Rottingdean
- Double-storey extensions in Burgess Hill
- Double-storey extensions in Worthing
Learn more about double-storey extensions, or see every project we cover in Brighton.

