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House Extension in London

Extend your London home instead of moving. Post your extension project on Quote2 and compare up to 3 quotes from vetted local builders who can manage the whole project from foundations to finish.

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No account needed · Free for homeowners · No obligation

What's Included

  • ✓Single and double-storey rear extensions
  • ✓Side return and wraparound extensions
  • ✓Kitchen-diner or open-plan extensions
  • ✓Garage conversion and annexe creation
  • ✓Garden room or home office extension
  • ✓Planning and building regs management

Planning your house extension in London

A house extension in London starts with understanding what's achievable under permitted development and what needs full planning permission. Single-storey rear extensions up to 4m (detached) or 3m (semi/terraced) generally fall under permitted development, subject to conditions. Double-storey extensions almost always require planning permission. Key cost factors include size and specification, foundation type, presence of a basement or tricky groundworks, and the level of finish. A good builder will advise on the planning route, manage structural engineers and building control, and provide a phased payment schedule. Post on Quote2 to find builders in London with proven extension experience.

How Quote2 Works

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Post your job

Describe your job in a few sentences. It takes under two minutes and is completely free.

2

Receive quotes

Local builders in London see your job and send you their quote and availability.

3

Choose & hire

Review profiles, read ratings, and pick the builder you trust. No pressure, no hidden fees.

Why London Homeowners Choose Quote2

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Free to post

Posting a job costs nothing. Tradespeople pay a small fee to contact you — keeping the platform fair.

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Rated tradespeople

Every builder on Quote2 is reviewed by real homeowners. Only deal with people who have a proven track record.

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Direct contact

Message builders directly — no cold calls, no pushy salespeople.

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Genuine competition

Up to 3 builders can respond to each job, so you get competitive quotes without being overwhelmed.

Covering London & Surrounding Areas

As well as London itself, our builders cover the surrounding areas including Croydon, Bromley, Ealing, Barnet and beyond. Wherever you are in the Greater London area, Quote2 can connect you with a qualified local professional.

Frequently Asked Questions

How much does a house extension cost in London?▼
House extension costs in London typically range from £1,500–£2,500 per square metre for a standard build quality, meaning a 20m² extension costs £30,000–£50,000. Premium finishes, structural complexity, and site access can push costs higher. Get 3 detailed quotes through Quote2.
Do I need planning permission for an extension in London?▼
Many single-storey extensions fall under permitted development and don't need planning permission. Double-storey extensions and properties in conservation areas usually require full planning consent. Your builder can advise, and London Council's planning portal lets you check rules for your specific address.
How long does a house extension take to build?▼
A typical single-storey kitchen extension takes 8–16 weeks to complete, including groundworks, structure, internal fit-out, and decoration. Larger or more complex extensions take longer. Always get a phased timeline from your builder at quote stage.
Will I need to move out during the extension?▼
For most rear extensions, you can stay in the property throughout — though there will be noise, dust, and a temporary loss of the room being extended into. Your builder will discuss how to minimise disruption when they quote via Quote2.

Get Quotes for Your House Extension in London

Post your job in minutes — it's free for homeowners. Compare quotes and hire with confidence.

Post Your Job Free

No account needed · Up to 3 quotes · No obligation