We are Design & Build basement conversion company based in London specialising in Design, Excavation, Construction, Waterproofing and Fit-outs. We can accommodate any basement build or conversion requirement in South West London.

We work with RIBA chartered architects who have extensive experience working in the conversion of basements, as well as constructing modern extensions and additional storeys. We work closely with the local Planning Authorities in London and pride ourselves in obtaining all permissions approved on time.

Our comprehensive approach delivers the finest results that are truly individual, transforming your ideas into breathtaking spaces.

Typically, we like to arrange an on-site visit to understand your vision, and get a feel of the space we will be transforming. We then go back to the drawing board and provide you with a couple of initial draft ideas, which we are confident will provide you with the inspiration to realise your unique vision.

If this sounds of interest, you can request a free consultation and we will get in touch to discuss your project.

Your initial site visit

We provide professional advice you need to fully understand the scope and viability of your project so you can move forward with confidence and knowledge.

Whether you’re looking for a new build basement or converting existing cellar into habitable space under your property, APT Basements have the perfect solution for you.

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Drop us a line

Unit 6, Zennor Road, Balham, London SW12 0PS


+44 (0)20 7223 6417

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Enjoy a new dimension

A basement is the ideal way to extend your living space in London. From designer bathrooms and kitchens to wireless media rooms, flood-lit swimming pools and walk-in wine cellars, a basement development opens up a world of possibility.

We examine your options to give you the most appropriate advice and detailed information on costs and timescales.


For help with your project…

Call or email now to discuss.


0207 223 6417

House Extension Builders in London | Renovation Extension Builders in London | House Construction Builders in London