Double-storey extensions across Greater Manchester
Our design and build teams take on double-storey extensions in Greater Manchester, from the first measured survey through planning and building control to the finished room.
- Guide priceFrom £36,000 inc VAT
- PlanningUsually a householder application
- Towns covered41
- Site visitFree, no obligation
Towns in Greater Manchester
- Altrincham
- Ashton-in-Makerfield
- Ashton-under-Lyne
- Atherton
- Bolton
- Bury
- Chadderton
- Cheadle Hulme
- Denton
- Droylsden
- Dukinfield
- Eccles
- Failsworth
- Farnworth
- Hazel Grove
- Heywood
- Hindley
- Horwich
- Hyde
- Irlam
- Leigh
- Manchester
- Middleton
- Oldham
- Prestwich
- Radcliffe
- Rochdale
- Royton
- Saddleworth
- Sale
- Salford
- Stalybridge
- Stockport
- Stretford
- Swinton
- Tyldesley
- Urmston
- Walkden
- Westhoughton
- Whitefield
- Wigan
What should I budget for a double-storey extension in Greater Manchester?
Prices below are for Greater Manchester, using the North West England factor of ×0.95. They are guide ranges including VAT for the build only, not a quote.
Typical rates in Greater Manchester: £1,470 to £2,850 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 3 m × 4 m, two floors 24 m² | £36,000 – £43,500 | £41,000 – £54,000 | £52,000 – £68,500 |
| 4 m × 4 m, two floors 32 m² | £47,000 – £56,500 | £54,500 – £71,500 | £69,500 – £91,500 |
| 4 m × 6 m, two floors 48 m² | £70,500 – £84,500 | £82,000 – £107,500 | £104,500 – £137,000 |
Try the guide-price tool to see a range for your own size and finish.
Included in a typical project
- Ground and first floor structure, roof tied into the existing roof
- Breaking through at both levels, stairs and landing changes where needed
- Householder planning application where needed
- Insulation, plastering, electrics and plumbing to finish
- Building regulations drawings and structural design
- Measured survey, design and planning drawings
The roof is what makes a two-storey extension look right or wrong. We match the pitch and materials of the main house wherever possible and plan the upstairs layout around the existing landing so the new rooms feel original rather than bolted on.
Working in Greater Manchester
Towns we cover in Greater Manchester include Manchester, Oldham, Wigan, Bolton, Stockport, Salford, Rochdale, Sale. The North West has a high share of Victorian and Edwardian terraces with rear yards and outriggers, plus large areas of inter-war semis in the suburbs.
Do I need planning permission in Greater Manchester?
In England a two-storey rear extension is permitted development only if it projects no more than 3 m from the original rear wall, sits at least 7 m from the rear boundary, matches the roof pitch and uses obscure, non-opening side windows upstairs. Most two-storey extensions therefore go through a householder planning application, which costs £548 from 1 April 2026 and normally takes about 8 weeks.
The planning position for a specific Greater Manchester address depends on its history and any designations, which is why we check it at the first visit.
Building regulations approval is separate from planning. In England you can use the council's building control team or a registered building control approver; a full plans application gets the drawings checked before work starts, and the inspector signs the work off with a completion certificate.
If the work involves a shared wall, building on the boundary, or digging foundations within 3 m (sometimes 6 m) of a neighbour's building, the Party Wall etc. Act 1996 applies and notice must be served before work starts: two months for work to a party wall, one month for new walls on the boundary and for excavations.
Applications are decided by the local planning authority (your district, borough or unitary council).
Our process, step by step
Site visits are free and there is no obligation. Where drawings are needed, the design stage is priced in writing before it starts.
Free site visit
First, a site visit: we look at the house, garden, access and drains and listen to what you need.
Design and approvals
We draw the design, agree it with you and handle planning or permitted development checks and building regulations.
Fixed written price
We confirm the build price in writing, based on the approved drawings and the finishes you have chosen.
Build and sign-off
We build it with one project manager, book the building control inspections and hand over the completion certificate.
Double-storey extension questions answered
How long does a double-storey extension take to build in Greater Manchester?
On site, typically 16 to 24 weeks once approvals are in place. Before that, allow 8–16 weeks design and approvals.
Who do I contract with for a double-storey extension in Greater Manchester?
Your contract is with S&K Property Investments and Improvement Ltd, which designs and manages the project and the build teams who carry it out.
Do I need building regulations approval in Greater Manchester?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Is a two-storey extension cheaper per square metre?
Usually. Our guide range is about £1,470 to £2,850 per m² of new floor area including VAT, compared with £1,660 to £3,230 per m² for single-storey work, because the foundations and roof are shared across two floors.
Do I need a Party Wall Agreement?
If you are in England or Wales and the work involves a shared wall or digging foundations close to a neighbour, the Party Wall etc. Act 1996 applies and notices must be served before work starts. We tell you which notices are needed.
Book a free site visit in Greater Manchester
We will measure up, check the planning position and give you honest guide figures.
- Free, no-obligation site visit
- Planning route checked before you spend on drawings
- Written price once the design is agreed
- Building control sign-off at the end
Prefer to talk? Call 0800 088 6341 or .
Book a free site visit
Tell us a little about the project and we will arrange a time.