Greater Manchester
Flat-roof rear extensions in Greater Manchester
Warm flat roofs with lanterns, parapets and long-life membranes. We design and build rear extensions across Greater Manchester, from Manchester and Oldham to Wigan, covering single-storey kitchen extensions, two-storey additions, side returns and wraparounds.
Flat roofs are the usual choice for rear extensions because they stay below first-floor windows and take a lantern neatly. Greater Manchester has long runs of terraced houses with back yards and alleys, plus 1930s semis further out. Yard extensions on terraces are often single-storey and close to both boundaries.
How much does a flat-roof rear extension cost in Greater Manchester?
For Greater Manchester we work from the North West England rate: £1,790–£2,910 per square metre of new floor, including VAT, standard specification. North West prices sit below our West Midlands baseline; access on terraced streets is the main variable.
| Size | Guide price inc VAT |
|---|---|
| 3 m wide × 4 m deep (12 m²) | £21,500–£35,000 |
| 4 m wide × 5 m deep (20 m²) | £35,500–£58,500 |
| 4 m wide × 6 m deep (24 m²) | £43,000–£70,000 |
Ground conditions, glazing, the roof and how far the house is opened up move the final figure within the range.
Do you need planning permission in Greater Manchester?
In England a single-storey rear extension can often be built under permitted development: up to 3 metres beyond the original rear wall of an attached house, or 4 metres on a detached house, no higher than 4 metres, with eaves no higher than 3 metres if any part is within 2 metres of a boundary.
New fabric must meet Approved Document L (2021 edition incorporating 2023 amendments): walls 0.18, roof 0.15 and floor 0.18 W/m²K, windows 1.4 W/m²K or Band B. Under the simple route, new windows, doors and rooflights should not exceed 25% of the extension floor area plus any openings removed; more glass is possible with a whole-house calculation.
Conservation areas, National Parks, National Landscapes and the Broads restrict permitted development, and listed buildings always need listed building consent.
Where in Greater Manchester do we work?
- Manchester
- Oldham
- Wigan
- Bolton
- Stockport
- Salford
- Rochdale
- Sale
- Bury
- Altrincham
- Middleton
- Ashton-under-Lyne
- Leigh
- Stretford
- Urmston
- Chadderton
- Eccles
- Tyldesley
- Hyde
- Walkden
- Prestwich
- Radcliffe
- Cheadle Hulme
- Heywood
- Denton
- Stalybridge
- Ashton in Makerfield
- Westhoughton
- Farnworth
- Saddleworth
- Hindley
- Golborne
- Droylsden
- Whitefield
- Swinton
- Royton
- Atherton
- Old Trafford
- Dukinfield
- Failsworth
- Hazel Grove
- Irlam
- Horwich
- Manchester City Centre
- Bramhall
- Ramsbottom
- Bredbury
- Hale
- Longsight
- Didsbury
- Fallowfield
- Littleborough
- Burnage
- Little Hulton
- Marple
- Cheetham Hill
- Lees
- Hollinwood
- Crumpsall
- Timperley
- Uppermill
- Ince-in-Makerfield
- Blackley
- Kearsley
- Little Lever
- Abram
FAQ
Questions people ask
How long does a flat roof last?
A well-built single-ply or GRP warm roof typically lasts 25 years or more.
Is a flat roof really flat?
No; it is built to falls so water drains to outlets or gutters.
Can I walk on it?
Not as a balcony without planning permission and a guarding design; it can be accessed for maintenance.
Do you cover all of Greater Manchester?
We cover 66 towns and districts in Greater Manchester, including Manchester, Oldham and Wigan.
Who builds the extension?
Vetted building teams working under contract to us; your contract is with S&K Property Investments and Improvement Ltd.