Extend your M23 with an extension

A flat roof extension is a great way to add extra space to your home without splashing out on the costs of a pitched roof extension. Often exempt from planning permission rules, you can build a flat roof extension up to 3 metres in height as long as it's not visible from a road. But how much do they cost in M23?

Build a flat roof extension cost in M23 - Sort by rates or availability

R A C Gas

From £21,608

(last active 02/10/26)

Location

Runcorn, WA7

Relax... you have found a reliable extension builder in M23. R A C Gas is a friendly and reliable company based in M23 who consider no job as too b...

Ethos Property Developments Limited

From £22,008

(last active 30/09/26)

Location

Stalybridge, SK15

Ethos Property Developments Limited is an established extension buildering business in M23. We come highly recommended and provide competitive quot...

Aquatec Builder

From £20,960

Member since November 2019

Location

Heywood, OL10

Reliable and experienced extension builders with competitive rates and good at keeping within budget. Happy to provide examples of extension builde...

David Anderson Builders

From £21,776

(last active 22/09/26)

Location

Walkden, M28

Relax... you have found a reliable extension builder in M23. David Anderson Builders is a friendly and reliable company based in M23 who consider n...

DC Contractors

From £21,792

(last active 22/09/26)

Location

Radcliffe, M26

Need to find an Extension Builder near you for all your extension buildering work?

DC Contractors provides a local, trusted extension build...

ESBP Specialists Ltd

From £21,960

(last active 22/09/26)

Location

Manchester, M26

Need to find an Extension Builder near you for all your extension buildering work?

ESBP Specialists Ltd provides a local, trusted extension...

We Build

From £21,848

(last active 22/09/26)

Location

Ashton-under-Lyne, OL6

Trusted and professional extension builder in M23. Experienced in all extension buildering work and keeping within budget and on quote. We Build ha...

Valdecor

From £21,184

(last active 22/09/26)

Location

Bardsley, OL8

20 years experience. 

Great recommendations. 

MK Builders

From £21,608

(last active 22/09/26)

Location

Middleton, M24

Need an Extension Builder in M23? MK Builders has been helping local clients (20 mile radius) with their extension buildering jobs for many years. ...

Fit-on Garage Doors

From £21,632

(last active 22/09/26)

Location

Bardsley, OL8

Trusted and professional extension builder in M23. Experienced in all extension buildering work and keeping within budget and on quote. Fit-on Gara...

Flat roof extension cost in M23

Estimates for build a flat roof extension near M23

A flat roof extension ranges from the cheapest of £20,960 (Aquatec Builder based in OL10) to the dearest of £22,008 (Ethos Property Developments Limited based in SK15), but these are just estimates. While they give you an idea of who will be better value, the best way to compare costs is to get real quotes. 

Find out how much your flat roof extension will cost in M23 by posting a job with HaMuch. We'll send it to extension builders in M23.


Get extension builder rates instantly

Get extension builder rates instantly (excluding VAT or callout charges)
Location in UKHourly RateDaily Rate
Build A Flat Roof Extension near Wythenshawe£31£229
Build A Flat Roof Extension near Gatley£31£230
Build A Flat Roof Extension near Sale£32£235
Build A Flat Roof Extension near Altrincham£32£228
Build A Flat Roof Extension near Trafford£32£235
Build A Flat Roof Extension near Stretford£32£235
Build A Flat Roof Extension near Old Trafford£32£236
Build A Flat Roof Extension near Cheadle Hulme£31£232
Build A Flat Roof Extension near Urmston£32£231
Build A Flat Roof Extension near Wilmslow£31£230

Estimates for common extension builder jobs in M23;

Whether you’re looking to extend your kitchen with a side return extension or you want to convert your basement into a liveable space, read our cost guides to get an idea of how much each project costs before getting a more accurate quote from our database of reliable tradespeople.

Underpin a building

Underpin a building - £17,138

Two storey extension

Two storey extension - £87,456

Build a timber frame extension

Build a timber frame extension - £25,638

Build a swimming pool

Build a swimming pool - £80,638

Single storey extension

Single storey extension - £47,752

Side return extension

Side return extension - £37,423

Install an RSJ

Install an RSJ - £1,838

Outbuilding

Outbuilding - £9,638

Build a Mansard loft conversion

Build a Mansard loft conversion - £51,638

Loft conversion

Loft conversion - £30,353

Build a kitchen extension

Build a kitchen extension - £41,638

Hip to gable loft conversion

Hip to gable loft conversion - £41,638

Granny annexe

Granny annexe - £86,638

Garden office

Garden office - £9,638

Convert a Garage

Convert a Garage - £15,638

Garage

Garage - £18,138

Build a flat roof extension

Build a flat roof extension - £21,638

Build a dormer loft conversion

Build a dormer loft conversion - £41,638

Concrete foundations

Concrete foundations - £5,888

Convert a bungalow loft

Convert a bungalow loft - £28,638

Convert a basement

Convert a basement - £33,423

More extensions & conversions cost guides...