Our services
House Extensions
A house extension is one of the most rewarding ways to add living space, light and value to a London home, and it lets you shape the property around the way you actually live. MVV designs and builds rear, side return and wrap-around extensions across West, South West, North West, Central and South East London, handling design, planning and construction as a single, accountable service.
How much does a house extension cost in London?
As a realistic starting point, all ex VAT and indicative: on typical London jobs priced on our estimator in October 2026, a single storey rear extension of about 20 m² of new floor, flat roofed with no rooflights, plus making good the room it joins, came to around £57,000, roughly £2,900 per square metre of new floor, and our minimum for a complete project, once finishes and fittings are included, is around £85,000, because even a small extension carries almost the same baseline of work as a larger one. A two storey side return adding around 48 m² of new floor area came to around £128,000. Pairing a 20 m² extension with a full refurbishment of a 130 m² house came to between £165,000 and £195,000. For new above ground space at a standard specification, £2,650 to £2,900 per square metre of new floor is a realistic inner London range before professional fees. These figures price windows, doors, any rooflights, sanitaryware and tiles for fitting only, with the products supplied by you, and leave out kitchen units, worktops and appliances. The rest depends on size, design, specification and the condition of the existing property, which is why the instant estimator prices yours from your own description and sends a realistic range to your inbox in minutes.
How long a house extension takes
Timescales vary with complexity, but a single-storey extension typically takes around two to three months on site once planning is in place and the design is agreed.
Planning permission
Most house extensions need planning permission, though some fall under permitted development depending on the borough. We manage the application for you and submit the documentation your local authority requires, keeping the approval process smooth.
Choosing the right design
Our designers work closely with you so the extension feels like a natural part of the house rather than an addition. Whether it is a rear kitchen extension, a side return or a wrap-around, we shape the space around how you live and how the light falls.
Adding value to your property
A well-designed house extension can significantly increase what your home is worth. Adding usable space, especially an open-plan kitchen or an extra bedroom, is among the most appealing improvements to future buyers in London.
A full design and build service
We deliver house extensions as a complete design and build service in London, from first concept and planning through construction to final finishes, so one team is accountable for the whole project.
House Extensions across London
- Fulham
- Chelsea
- Notting Hill
- Chiswick
- Wimbledon
- Pimlico
- Belsize Park
- Hampstead
- Mayfair
- Marylebone
- Blackheath
- Borough
- Kensington
- Streatham
- St John's Wood
- Maida Vale
- Little Venice
- Regent's Park
- Primrose Hill
- West Hampstead
- Fitzrovia
- Bloomsbury
- Covent Garden
- Soho
- St James's
- Westminster
- Belgravia
- Knightsbridge
- Bayswater
- Paddington
- Clerkenwell
- Holland Park
- South Kensington
- Earl's Court
- Sevenoaks
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Read before you start
Guides on this work
Straight answers on cost, planning and process, with costs from typical jobs priced on our estimator.
- How much does a house extension cost in London in 2026?Read
- How much does a two storey extension cost in London in 2026?Read
- Rear Extensions in London: Cost, Planning and DesignRead
- How much will my extension cost? Build it in 3D and get a free London estimateRead
- Design costs for a London home in 2026: architects, engineers, surveyors and approvalsRead
- Rear Extension or Side Return: Which Is Right for Your London Home?Read
Related projects
Where this work comes to life
A selection of completed MVV projects delivered with this service.
