1 review
From £58,840
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 £55,480
Need the extension buildering job done quickly without breaking the bank? SH Enterprise offer fast, reliable, and affordable extension buildering s...
From £61,240
Reliable and experienced extension builders with competitive rates and good at keeping within budget. Happy to provide examples of extension builde...
From £62,840
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 £60,600
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 £58,840
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 £60,600
Trusted and professional extension builder in WD18. Experienced in all extension buildering work and keeping within budget and on quote. DC Build &...
From £58,040
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 £61,080
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 £63,480
Reliable and experienced extension builders with competitive rates and good at keeping within budget. Happy to provide examples of extension builde...

"Single storey extension" - WATFORD, job posted 01/01/70
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 - £17,755

Two storey extension - £88,383

Build a timber frame extension - £26,255

Build a swimming pool - £81,255

Single storey extension - £60,104

Side return extension - £44,371

Install an RSJ - £2,455

Outbuilding - £10,255

Build a Mansard loft conversion - £52,255

Loft conversion - £36,143

Build a kitchen extension - £42,255

Hip to gable loft conversion - £42,255

Granny annexe - £87,255

Garden office - £10,255

Convert a Garage - £16,255

Garage - £18,755

Build a flat roof extension - £22,255

Build a dormer loft conversion - £42,255

Concrete foundations - £6,505

Convert a bungalow loft - £29,255

Convert a basement - £40,371