From £87,280
In an unstable market house extensions are often the most viable option, helping you to get the most out of the space you have without the addition...
From £87,312
Relax... you have found a reliable extension builder in Watford. Frame Brickwork is a friendly and reliable company based in Watford who consider n...
From £89,760
Trusted and professional extension builder in Watford. Experienced in all extension buildering work and keeping within budget and on quote. Design ...
From £87,424
Experienced extension builder ready to quote for your work. 1st Choice Builders UK is the best extension builder in Watford. No obligation free quo...
From £87,024
A&T Building is an established extension buildering business in Watford. We come highly recommended and provide competitive quotes for your work.
From £87,224
T N Roofing is an established extension buildering business in Watford. We come highly recommended and provide competitive quotes for your work.
From £87,144
Primrose Projects is an established and experienced local extension builder in Watford. Please contact us for a free, no obligation quote and compe...
From £87,464
In an unstable market house extensions are often the most viable option, helping you to get the most out of the space you have without the addition...
From £87,024
Cannon Build Solutions is an established extension buildering business in Watford. We come highly recommended and provide competitive quotes for yo...
From £87,224
Relax... you have found a reliable extension builder in Watford. C S C BUILDINGS LTD is a friendly and reliable company based in Watford who consid...

Building a granny annexe ranges from £87,024 (A&T Building based in WD18) to £89,760 (Design & Build Builders Ltd based in WD18), but these are just estimates that can help give you an idea of who will be better value in your area.
The best thing to do is to get quotes to build a granny annexe in Watford by posting a job with HaMuch. We will send it to extension builders in Watford who will be happy to help you.
| Location in UK | Hourly Rate | Daily Rate |
|---|---|---|
| Granny Annexe near Watford | £43 | £278 |
| Granny Annexe near Bushey | £42 | £276 |
| Granny Annexe near Rickmansworth | £42 | £278 |
| Granny Annexe near Borehamwood | £42 | £270 |
| Granny Annexe near Harrow | £43 | £271 |
| Granny Annexe near Hillingdon | £63 | £276 |
| Granny Annexe near Gerrards Cross | £43 | £282 |
| Granny Annexe near St Albans | £63 | £288 |
| Granny Annexe near Dacorum | £42 | £269 |
| Granny Annexe near Hemel Hempstead | £42 | £270 |
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 - £17,988

Two storey extension - £88,732

Build a timber frame extension - £26,488

Build a swimming pool - £81,488

Single storey extension - £64,760

Side return extension - £46,990

Install an RSJ - £2,688

Outbuilding - £10,488

Build a Mansard loft conversion - £52,488

Loft conversion - £38,325

Build a kitchen extension - £42,488

Hip to gable loft conversion - £42,488

Granny annexe - £87,488

Garden office - £10,488

Convert a Garage - £16,488

Garage - £18,988

Build a flat roof extension - £22,488

Build a dormer loft conversion - £42,488

Concrete foundations - £6,738

Convert a bungalow loft - £29,488

Convert a basement - £42,990