From £6,754
At Ferdas Design & Build Ltd we have been fitting bespoke bathrooms since 2013. We pride ourselves on being the go-to bathroom fitters for discerni...
1 review
From £6,442
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 £6,274
Need the extension buildering job done quickly without breaking the bank? SH Enterprise offer fast, reliable, and affordable extension buildering s...
From £6,562
Reliable and experienced extension builders with competitive rates and good at keeping within budget. Happy to provide examples of extension builde...
From £6,642
Need an Extension Builder in WD18? Samuele Paolini has been helping local clients (5 mile radius) with their extension buildering jobs for many ye...
From £6,530
Member since August 2026
Relax... you have found a reliable extension builder in WD18. ABC Associates STRUCTURES 4 U is a friendly and reliable company based in WD18 who co...
From £6,442
Need an Extension Builder in WD18? VA Structures has been helping local clients (10 mile radius) with their extension buildering jobs for many year...
From £6,530
Trusted and professional extension builder in WD18. Experienced in all extension buildering work and keeping within budget and on quote. DC Build &...
From £6,402
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 £6,554
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...

Concrete foundations range from the £6,274 (SH Enterprise based in EC1V) to £6,754 (Ferdas Design & Build Ltd based in W3) in WD18.
Comparing extension builders estimates for laying concrete foundations gives you an idea of who will be better value, but the best way to compare costs is to get actual quotes.
Find out the exact cost of laying concrete foundations in WD18 by posting a job with HaMuch. We will send it to extension builders who can give you a detailed quote.
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 - £17,763

Two storey extension - £88,395

Build a timber frame extension - £26,263

Build a swimming pool - £81,263

Single storey extension - £60,264

Side return extension - £44,461

Install an RSJ - £2,463

Outbuilding - £10,263

Build a Mansard loft conversion - £52,263

Loft conversion - £36,218

Build a kitchen extension - £42,263

Hip to gable loft conversion - £42,263

Granny annexe - £87,263

Garden office - £10,263

Convert a Garage - £16,263

Garage - £18,763

Build a flat roof extension - £22,263

Build a dormer loft conversion - £42,263

Concrete foundations - £6,513

Convert a bungalow loft - £29,263

Convert a basement - £40,461