We transformed an existing basement in a Georgian building in Fitzrovia into a sleek modern home. The basement was extended at the rear and a new three storey extension to the mews was created. This has resulted in a triplex apartment flooded with light from the glazed roof and two light wells. The interior is calm with white walls, timber panelling and a white resin floor. A bespoke birch plywood stair links the three levels. Colour is added once the doors to the kitchen, bathrooms and cupboards are opened to reveal jewel box bright interiors. The bedroom is separated from the living area by a bamboo glazed sliding screen, so that the space can be open plan if required. The mezzanine in the roof space provides a sanctuary for work or play.