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Flat roof extension cost in London

A flat roof extension is a great way to add extra space to your home without splashing out on the costs of a pitched roof extension. Often exempt from planning permission rules, you can build a flat roof extension up to 3 metres in height as long as it's not visible from a road. But how much do they cost in London?

A flat roof extension ranges from the cheapest of £20,160 (London Design And Build based in SW1A) to the dearest of £21,944 (Adamko Dry Lining London based in WC2N), but these are just estimates. While they give you an idea of who will be better value, the best way to compare costs is to get real quotes. 

Find out how much your flat roof extension will cost in London by posting a job with HaMuch. We'll send it to extension builders in London.

Estimates for flat roof extension near London

Estimates for common extension builder jobs in London;

JobEstimate
Underpinning a house£17,337
Build a two storey extension£87,756
Build a timber frame extension£25,837
Install a swimming pool£80,837
Cost to build a single storey extension£51,742
Cost to build a side return extension£39,668
Install an RSJ£2,037
Build an outbuilding£9,837
Build a mansard loft conversion£51,837
Cost of a loft conversion£32,223
Build a kitchen extension£41,837
Build a hip to gable loft conversion£41,837
Build a granny annexe£86,837
Build a garden office£9,837
Convert a garage£15,837
Build a new garage£18,337
Build a flat roof extension£21,837
Build a dormer loft conversion£41,837
Lay a concrete foundation£6,087
Convert a bungalow loft£28,837
Basement conversion cost£35,668
2. Enter postcode to get estimate
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Rates for other London trades

Appliance Repair Specialist
Bathroom Fitter
Builder
Carpenter and Joiner
Cleaner
Conservatory Specialist
Door Fitter
Drain Specialist
Driveway Specialist
Electrician
Extension Builder
Fencer
Fire and Security Specialist
Flooring Specialist
Gardener
Handyman
Heating Engineer
Kitchen Fitter
Landscaper
Painter and Decorator
Patio and Path Specialist
Plasterer
Plumber
Removals and Storage
Roofer
Tiler
Window Fitter
Flat roof extension cost in London
Estimate Flat roof extension cost in London based on hourly/daily rate (excluding VAT or callout charges)
Business name Flat roof extension cost
Adamko Dry Lining London, Greater London, WC2N £21,944
Elv8 Interiors, Greater London, W1B £21,944
Big Mamma, Greater London, W1F £21,944
London Projects Ltd, 11 Carteret Street, London, Greater London, SW1H £21,848
My Lady Builder, Greater London, WC2H £21,944
My Trusted Builder, London, Greater London, wc2h £21,848
Whitehorse Build London, Greater London, WC2H £21,944
ElleHaus, Greater London, WC2H £21,944
ORO Projects, Greater London, WC2H £21,944
HouseUP, 71-75 Shelton Street, Covent Garden, London, WC2H £21,848
Gil Construction Ltd, Greater London, WC2H £21,944
House Rendering Ltd, 71-75, Shelton Street, Covent Garden, Greater London, WC2H £21,848
Rucco Property, Greater London, WC2H £21,944
Matstone Projects Limited, Greater London, WC2H £21,944
Cornerstone, Greater London, W1F £21,944
Sehem Design, london, W1F £21,944
Mayfair Design, Greater London, W1J £21,944
Luxe Refurbs, 16 Berkeley Street, London, Greater London, W1J £21,840
We Love Build - Three Arches, London, Greater London, W1J £21,840
We Love Build, Greater London, W1J £21,944
London Design And Build , Roehampton, SW1A £20,160
Starfish Properties, 14 Hanover Street, 3rd Floor, London, W1S £21,848
TipTop Joinery & Build, London, Greater London, WC1V £21,848
Infinite CM, Greater London, SE1 £21,936
Elite Building, 7 Bell Yard, London, Greater London, WC2A £21,848

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Get extension builder rates instantly
Location in UKHourly RateDaily Rate
Flat Roof Extension near Belgravia£38£237
Flat Roof Extension near Lambeth£38£237
Flat Roof Extension near Camden Town£38£238
Flat Roof Extension near Chelsea£38£238
Flat Roof Extension near Islington£39£237
Flat Roof Extension near Camberwell£38£237
Flat Roof Extension near Kensington£38£238
Flat Roof Extension near Bethnal Green£39£236
Flat Roof Extension near Hackney£39£237
Flat Roof Extension near Fulham£38£238
Flat Roof Extension near Hammersmith£38£238
Flat Roof Extension near Earlsfield£38£238
Flat Roof Extension near Greenwich£38£235
Flat Roof Extension near Muswell Hill£38£237
Flat Roof Extension near Lewisham£38£236
Flat Roof Extension near Wimbledon£37£234
Flat Roof Extension near Plaistow£37£234
Flat Roof Extension near Brent Cross£37£237
Flat Roof Extension near Walthamstow£39£238
Flat Roof Extension near Merton£38£236
Flat Roof Extension near Ealing£38£237
Flat Roof Extension near Redbridge£36£232
Flat Roof Extension near Bromley£37£231
Flat Roof Extension near Croydon£37£233
Flat Roof Extension near Barking£37£228
Flat Roof Extension near Kingston Upon Thames£37£235
Flat Roof Extension near Sutton£37£234
Flat Roof Extension near High Barnet£37£236
Flat Roof Extension near Harrow£37£235
Flat Roof Extension near Hounslow£37£243
Flat Roof Extension near Richmond Upon Thames£37£236
Flat Roof Extension near Bexley£36£231
Flat Roof Extension near Hillingdon£56£240
Flat Roof Extension near Romford£39£237