basement conversions london
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Basement Contractors specialists

Looking for a basement conversion company to build you a luxurious basement? So you can extend downwards to create an entertainment space, living space, a cinema room, a home office or an entirely new storey for your London home. In that case, you’ll want to choose the best – basement specialists with years of experience and hundreds of satisfied clients – you’ll want to choose Proficiency Design & Build.

basement specialists

Down is the new up. In a city where space is a scarce resource one solution is to dig deep.

Stunning London Basement Design & Built

London: 8 million people squeezed into just over 600 square miles – no wonder it can sometimes feel cramped. With very little space to extend outwards and restrictions on extending upwards, if you love your home too much to move but need the extra floor space it may be time to consider a basement conversion. We’re not going to lie, a basement conversion in London can be costly and time-consuming to construct, however, the end results can be magnificent. From a small wine cellar maintained at the perfect temperature and lined with floor to ceiling racks to an entire additional storey styled from floor to ceiling to be every bit as stunning as the home above, and everything in-between, our team have designed and built them all.

ground floor basement view to garden

Step by Step, What to Expect

Types of Basement Conversion

basement contractors


If you already have the space, but it’s dark and dank, ask for a quote for a redesign and refurbishment, a renovation to create a stunning room you’ll love to escape to.

london basement conversions


To create a new basement room or rooms you’ll need designs, a specialist builder and potentially planning permission. Our team can handle it all for you.

cellar conversion


Whether you have a few bottles you’re proud of or an entire collection, a wine cellar at home is a popular reason for a downwards extension.

End-to-End Basement Contractors

Construction techniques have moved on a very long way from the cold, dim underground rooms people used to call basements. Today a basement conversion is a light, spacious extension to your family home. With lightwells and LED lighting, you control the illumination. Advanced sound proofing means you can enjoy your cinema room’s new speakers to their full without disturbing others in your home. Modern tech in cabling, broadband and mobile signal boosters can mean your new home office is always business ready. You could create a spacious lounge or a playroom, an expansive kitchen/dining room or a new bedroom or two with en suites. Whatever you wish a basement company to create for you, we will be there from design to completion to guide, advise, support, give ideas and build your dream basement conversion.


open plan kitchen extension
The Avenue, Queen's Park

Rear and side extension
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navy blue kitchen
Islington, Canonbury

Rear Extension
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Cambridge Road, Twickenham

Extension & Loft Conversion
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Hillfield Road, West Hampstead

Wrap Around Extension
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What Does a Basement Extensions Cost?

London basement conversions come at a cost, what that may be is determined by the hundred and one decisions you make at the design stage of your project. What we can assure you of is that we will squeeze every last ounce of potential from each penny of your budget, respecting your limits and keeping you informed of progress every step of the way. Our basement conversion company of architects, interior designers, builders and tradespeople are not only craftsmen and women, they are also committed to keeping our promises to you on matters of time and budget.

  • Swimming pool
  • Gym
  • Sauna
  • Living space
  • Utility room
  • Storage space
Building a room

Contact us

To find out how we can help you to transform your basement conversions in london contact us today. We’re here to answer any and all questions or to book a time that’s convenient to you for one of our team member to come round to discuss your plans.


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