From £10,048
Experienced extension builder ready to quote for your work. J&J Building Solutions is the best extension builder in SE7. No obligation free quotes ...
From £10,312
Reliable and experienced extension builders with competitive rates and good at keeping within budget. Happy to provide examples of extension builde...
From £10,560
Our homes need to be regularly maintained and from time to time they need to be rejuvenated, modernised and enhanced. When it comes to building wor...
From £10,096
Experienced extension builder ready to quote for your work. Mr is the best extension builder in SE7. No obligation free quotes and many happy custo...
From £9,984
JK Doors is a trusted extension builder serving customers in SE7 and the surrounding area. Contact us to today to get a competitive quote for exten...
From £10,192
NIECEIC / NAAPIT GASSAFE WATER REGULATIONS We offer services towards completion of high end construction projects to dis...
From £10,392
Need an Extension Builder in SE7? Samuele Paolini has been helping local clients (5 mile radius) with their extension buildering jobs for many yea...
From £10,312
skilled worker who specializes in completing a wide range of building and renovation projects
From £10,616
HOUSE BUILDING SERVICES LIMITED is a trusted extension builder serving customers in SE7 and the surrounding area. Contact us to today to get a comp...
From £9,888
Member since April 2025
Trusted and professional extension builder in SE7. Experienced in all extension buildering work and keeping within budget and on quote. GR MAINTENA...

Outbuilding costs in SE7 range from the cheapest of £9,888 (GR MAINTENANCE LTD based in IG11) to the dearest of £10,616 (HOUSE BUILDING SERVICES LIMITED based in DA16), but these are just estimates.
Comparing extension builders estimates for building an outbuilding gives you an idea of who will be better value, but the best way to compare costs is to get actual quotes.
Get rates and quotes to build an outbuilding in SE7 by posting a job with HaMuch and we will send it to extension builders.
| Borough in London |
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| Outbuilding in Charlton |
| Outbuilding in Blackheath |
| Outbuilding in Greenwich |
| Outbuilding in Woolwich |
| Outbuilding in Canning Town |
| Outbuilding in Lewisham |
| Outbuilding in Deptford |
| Outbuilding in Grove Park |
| Outbuilding in Canary Wharf |
| Outbuilding in Eltham |
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 - £17,740

Two storey extension - £88,360

Build a timber frame extension - £26,240

Build a swimming pool - £81,240

Single storey extension - £59,800

Side return extension - £44,200

Install an RSJ - £2,440

Outbuilding - £10,240

Build a Mansard loft conversion - £52,240

Loft conversion - £36,000

Build a kitchen extension - £42,240

Hip to gable loft conversion - £42,240

Granny annexe - £87,240

Garden office - £10,240

Convert a Garage - £16,240

Garage - £18,740

Build a flat roof extension - £22,240

Build a dormer loft conversion - £42,240

Concrete foundations - £6,490

Convert a bungalow loft - £29,240

Convert a basement - £40,200