From £22,048
Experienced extension builder ready to quote for your work. J&J Building Solutions is the best extension builder in HA2. No obligation free quotes ...
1 review
From £22,192
NIECEIC / NAAPIT GASSAFE WATER REGULATIONS We offer services towards completion of high end construction projects to dis...
"Did callout made safe my elctrical work thanks" - reviewed 16/05/23, REECYRUSSO
From £22,392
Need an Extension Builder in HA2? Samuele Paolini has been helping local clients (5 mile radius) with their extension buildering jobs for many yea...
From £22,280
Member since August 2026
Relax... you have found a reliable extension builder in HA2. ABC Associates STRUCTURES 4 U is a friendly and reliable company based in HA2 who cons...
From £22,192
Need an Extension Builder in HA2? VA Structures has been helping local clients (10 mile radius) with their extension buildering jobs for many years...
From £22,280
Trusted and professional extension builder in HA2. Experienced in all extension buildering work and keeping within budget and on quote. DC Build & ...
From £22,312
Reliable and experienced extension builders with competitive rates and good at keeping within budget. Happy to provide examples of extension builde...
From £22,152
I am a qualified, builder, electrician and plumber. I have been working in the construction industry for over 23 years and have built everything fr...
From £22,304
Hi we have 15 years of experience in building and construction industry our specialization is bathrooms and renovations please have a look at the w...
From £23,024
Buci builders ltd is a trusted extension builder serving customers in HA2 and the surrounding area. Contact us to today to get a competitive quote ...

A flat roof extension ranges from the cheapest of £22,048 (J&J Building Solutions based in SW16) to the dearest of £23,024 (Buci builders ltd based in SE27), 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 HA2 by posting a job with HaMuch. We'll send it to extension builders in HA2.
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 - £17,818

Two storey extension - £88,476

Build a timber frame extension - £26,318

Build a swimming pool - £81,318

Single storey extension - £61,352

Side return extension - £45,073

Install an RSJ - £2,518

Outbuilding - £10,318

Build a Mansard loft conversion - £52,318

Loft conversion - £36,728

Build a kitchen extension - £42,318

Hip to gable loft conversion - £42,318

Granny annexe - £87,318

Garden office - £10,318

Convert a Garage - £16,318

Garage - £18,818

Build a flat roof extension - £22,318

Build a dormer loft conversion - £42,318

Concrete foundations - £6,568

Convert a bungalow loft - £29,318

Convert a basement - £41,073