Two-storey extensions in Lancashire
Two-storey extensions in Lancashire: guide prices for North West England, the rules that apply in England, and the towns we cover.
Lancashire at a glance
- Nation
- England
- Price region
- North West England
- Postcode areas
- BB, FY, L, LA, OL, PR, WN
- Main town
- Preston
- Towns listed
- 30
- Site visits
- Free, no obligation
Choose your town
- Preston
- Burnley
- Blackburn
- Blackpool
- Morecambe
- Lancaster
- Lytham St Annes
- Skelmersdale
- Leyland
- Accrington
- Chorley
- Darwen
- Thornton-Cleveleys
- Nelson (Lancashire)
- Fleetwood
- Ormskirk
- Rawtenstall
- Colne
- Poulton-le-Fylde
- Heysham
- Haslingden
- Cleveleys
- Clitheroe
- Clayton-le-Woods
- Bacup
- Great Harwood
- Padiham
- Barnoldswick
- Brierfield
- Garstang
Guide prices in North West England
| Extension type | Per m² | Typical project |
|---|---|---|
| Two-storey rear extension | £1,900–£2,560 per m² | £53,000–£72,000 |
| Two-storey side extension | £1,950–£2,610 per m² | £82,000–£109,500 |
| Two-storey wraparound extension | £2,040–£2,800 per m² | £114,500–£157,000 |
| Part single, part two-storey | £1,900–£2,610 per m² | £68,500–£94,000 |
| Extension over a garage | £1,660–£2,420 per m² | £30,000–£43,500 |
| First-floor extension over an existing single storey | £1,710–£2,470 per m² | £24,000–£34,500 |
| Two-storey front extension | £2,090–£2,850 per m² | £25,000–£34,000 |
Including VAT, Standard spec. See all prices and fees.
Lancashire towns we list: Preston (PR1), Burnley (BB10), Blackburn (BB1), Blackpool (FY1), Morecambe (LA4), Lancaster (LA1), Lytham St Annes (FY8) and Skelmersdale (WN8). Every other address in Lancashire is covered as well.
Which type suits your house?
Which type suits your house in Lancashire depends mostly on where you have room. A deep garden points to a rear extension; space beside the house points to a side or over-garage extension; a house that already has a single-storey extension can often take a first floor on top.
The rules in England
Lancashire 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 Lancashire
How much does a two-storey extension cost in Lancashire?
In North West England our guide for a two-storey rear extension is £1,900–£2,560 per m² including VAT, about £53,000–£72,000 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 Lancashire?
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 Lancashire?
Yes. We list the main towns here, but we cover the whole of Lancashire 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.