Two-storey extensions in Berkshire
We cover all of Berkshire for two-storey and first-floor extensions. Pick a town or an extension type below.
Berkshire at a glance
- Nation
- England
- Price region
- South East England
- Postcode areas
- GU, RG, SL
- Main town
- Reading
- Towns listed
- 14
- Site visits
- Free, no obligation
Choose your town
- Reading
- Slough
- Bracknell
- Maidenhead
- Wokingham
- Newbury
- Lower Earley
- Windsor
- Crowthorne
- Thatcham
- Sandhurst
- Ascot
- Burnham
- Sunninghill
Guide prices in South East England
| Extension type | Per m² | Typical project |
|---|---|---|
| Two-storey rear extension | £2,200–£2,970 per m² | £61,500–£83,000 |
| Two-storey side extension | £2,260–£3,030 per m² | £94,500–£127,000 |
| Two-storey wraparound extension | £2,360–£3,250 per m² | £132,500–£181,500 |
| Part single, part two-storey | £2,200–£3,030 per m² | £79,000–£109,000 |
| Extension over a garage | £1,930–£2,800 per m² | £34,500–£50,500 |
| First-floor extension over an existing single storey | £1,980–£2,860 per m² | £27,500–£40,000 |
| Two-storey front extension | £2,420–£3,300 per m² | £29,000–£39,500 |
Including VAT, Standard spec. See all prices and fees.
Across Berkshire we cover Reading (RG1), Slough (SL1), Bracknell (RG12), Maidenhead (SL6), Wokingham (RG40), Newbury (RG14), Lower Earley (RG2) and Windsor (SL4), plus the smaller places around them.
Which type suits your house?
The boundaries usually decide it. Two-storey work close to a neighbour needs careful design for light and privacy, so at the visit in Berkshire we measure distances to every boundary before suggesting a type.
The rules in England
Berkshire is in England. Two-storey rear: up to 3 m deep and 7 m from the rear boundary under permitted development. Side, wraparound and front: planning permission. Householder planning application: £548 (or £575 for applications made from 8 December 2026). Lawful development certificate: £274 (about £288 for applications from 8 December 2026). Councils should decide householder applications within 8 weeks of validation.
The full England rules explained
Extension types
- Two-storey rear extensions
- Two-storey side extensions
- Two-storey wraparound extensions
- Part single, part two-storey extensions
- Extensions over a garage
- First-floor extensions
- Two-storey front extensions
By house type
- Two-storey extensions for semi-detached houses
- Two-storey extensions for detached houses
- Two-storey extensions for end-of-terrace houses
Rooms and uses
- Kitchen extensions with bedrooms above
- Extra bedroom and en-suite extensions
- Two-storey annexe extensions
- Garage conversions with a room above
Design and approvals
- Two-storey extension plans and drawings
- Planning permission for two-storey extensions
- Structural engineering for two-storey extensions
- Building regulations for two-storey extensions
- Party wall notices for extensions
- Design and build two-storey extensions
Questions about extensions in Berkshire
How much does a two-storey extension cost in Berkshire?
In South East England our guide for a two-storey rear extension is £2,200–£2,970 per m² including VAT, about £61,500–£83,000 for a 4 m × 3.5 m footprint on two floors (28 m² of new floor space). Side and wraparound extensions cost a little more per m².
Do I need planning permission in Berkshire?
Two-storey rear: up to 3 m deep and 7 m from the rear boundary under permitted development. Side, wraparound and front: planning permission. Householder planning application: £548 (or £575 for applications made from 8 December 2026). Lawful development certificate: £274 (about £288 for applications from 8 December 2026).
Do you cover the whole of Berkshire?
Yes. We list the main towns here, but we cover the whole of Berkshire including villages. The first site visit is free.
What happens at the first visit?
We look at your house, the boundaries, access and drains, talk through what you need and explain the approvals. Then we price the design stage, including the measured survey, in writing.