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J.M.B Design and Build Ltd are a leading house extension builder in North London.

We have constructed a range of house extensions in Barnet, from single-storey all the way through to multi-storey extensions.

Previous London building projects have taken place on Fox Lane, Galley Lane, Grove Park and more.

Are you considering a house extension in North London?

Why choose JMB?

  • Award-winning building contractor

  • Decades of combined experience

  • Highly regarded in North London

  • Never comprising on quality

  • Over 50 five-star reviews

  • Highly skilled architects

  • Highly skilled builders




More information on house extensions with JMB Design and Build

Looking to expand your living space in North London?


Look no further!


JMB Design and Build is an award-winning building contractor serving various Hertfordshire and North London areas.


We offer premium house extension solutions tailored to your bespoke needs.

Our expert team specialises in crafting seamless house extensions that not only enhance your living space but also add value to your property in North London.


Whether you crave a stylish kitchen extension, a spacious loft conversion, or a functional home office addition, we've got you covered.

Why choose JMB Design and Build for your house extensions in North London?

  • Award-winning expertise: With years of experience and accolades in the industry, we deliver unparalleled craftsmanship and quality.

  • Tailored solutions: We understand that every homeowner in North London has unique requirements. That's why we work closely with you to design and build extensions that match your vision and lifestyle.

  • Local expertise: As a trusted name in Hertfordshire and North London, we deeply understand the local regulations and architectural styles, ensuring smooth project execution from start to finish.


Previous North London House Extension Projects


Grove Park, Haringey

We were approached by our London-based client, who wanted to repurpose unused garden space into a rear extension. Following conversations with our client, we implemented their bespoke requirements into our works.


Fox Lane, Southgate

This beautiful Victorian house was transformed with a stunning rear extension.


The full width glass bi-folds and skylight allow the modern kitchen to be flooded with light making an airy, contemporary space perfect for family living.


Galley Lane, Barnet

Our clients’ old family home was a modest 3 bedroom bungalow based in Barnet, North London, with lots of potential.


Our client had visions of converting it into a luxury, modern home that the whole family would have space to entertain and enjoy. Working closely with his architect we have transformed the property into a stunning 5 bedroom, 2 en-suite, beautiful property with all the latest amenities.

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