1 review
From £18,692
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 £18,524
Need the extension buildering job done quickly without breaking the bank? SH Enterprise offer fast, reliable, and affordable extension buildering s...
From £18,812
Reliable and experienced extension builders with competitive rates and good at keeping within budget. Happy to provide examples of extension builde...
From £18,892
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 £18,780
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 £18,692
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 £18,780
Trusted and professional extension builder in WD18. Experienced in all extension buildering work and keeping within budget and on quote. DC Build &...
From £18,652
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 £18,804
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 £18,924
Reliable and experienced extension builders with competitive rates and good at keeping within budget. Happy to provide examples of extension builde...

Builders charge between £18,524 (SH Enterprise based in EC1V) and £18,924 (LALI BUILDERS based in NW10) in WD18 to build a garage, but these costs are only estimates.
Comparing extension builders estimates for building a garage gives you an idea of who will be better value, but the best way to compare costs is to get actual quotes.
Get real quotes to build a new garage in WD18 by posting a job with HaMuch and we will send it to extension builders in WD18.
| Borough in London |
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| Garage in West Watford |
| Garage in Watford |
| Garage in Watford |
| Garage in Oxhey |
| Garage in North Watford |
| Garage in Potters Bar |
| Garage in Bushey Heath |
| Garage in Northwood |
| Garage in Garston |
| Garage in Rickmansworth |
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