From £40,830
Bermondsey, SE1
Need an Extension Builder in SE1? GILL BUILDING CONTRACTORS has been helping local clients (5 mile radius) with their extension buildering jobs for...
From £37,410
Stanrock Building Services Ltd is a trusted extension builder serving customers in SE1 and the surrounding area. Contact us to today to get a compe...
From £43,170
Greater London, SE1
Combining a creative and professional approach with extensive industry experience. We offer full service packages - from high end refurbishments, t...
From £38,850
Our interior design service helps people to live better through interior architecture that solves problems, anticipates their needs and creates a h...
From £40,830
Greater London, SE1
Catch-all residential & commercial property maintenance and management service including intelligent A/V installation, We've focussed on SE1 for 8 ...
From £36,150
Trusted and professional extension builder in SE1. Experienced in all extension buildering work and keeping within budget and on quote. D & S CONST...
From £39,750
Greater London, SE1
Experienced extension builder ready to quote for your work. Space Design Construction Services Ltd is the best extension builder in SE1. No obligat...
From £37,770
Need to find an Extension Builder near you for all your extension buildering work?
AGRI CONSTRUCTION provides a local, trusted extension bu...
From £42,270
AAA Design Decorators are here to help customers who need an Extension Builder in SE1. We offer a competitive rate to complete all your extension b...
From £41,820
Propia Limited is an established and experienced local extension builder in SE1. Please contact us for a free, no obligation quote and competitive ...

Comparing extension builders estimates for a Convert a basement gives you an idea of who will be better value but the best way to compare costs is to get actual quotes.
What to do - Get rates and quotes for the cost to convert a basement in SE1 by posting a job with HaMuch and we will send it to extension builders in SE1.
"Basement conversion" - LAMBETH, job posted 05/02/25
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 - £17,712

Two storey extension - £88,318

Build a timber frame extension - £26,212

Build a swimming pool - £81,212

Single storey extension - £59,240

Side return extension - £43,885

Install an RSJ - £2,412

Outbuilding - £10,212

Build a Mansard loft conversion - £52,212

Loft conversion - £35,738

Build a kitchen extension - £42,212

Hip to gable loft conversion - £42,212

Granny annexe - £87,212

Garden office - £10,212

Convert a Garage - £16,212

Garage - £18,712

Build a flat roof extension - £22,212

Build a dormer loft conversion - £42,212

Concrete foundations - £6,462

Convert a bungalow loft - £29,212

Convert a basement - £39,885