Threefold Architects have designed and project managed the complete refurbishment and extension of a Victorian mews house in Knightsbridge, London. The site is nestled between the imposing terraced houses of Cadogan Square and the exclusive shops of Sloane Street, within the Hans Town Conservation Area. Overcoming the combined constraints of the typical mews site and the tight planning and conservation restrictions of the area, the design strategy sought to create a spacious and light filled new build modern and hi-tech home, hidden behind a retained period facade. Central to this are two large, frameless skylights on the roof of the house. These flood light into the rear of the building and down into the basement through a lightweight glass and steel helical staircase hanging within a treble height void. The volume of the original mews has been extended both up into the roof to create a luxurious master bedroom suite and down into an extra deep basement to create room for a sauna, steam room, gym, golf simulator and an additional bedroom. The ground floor of the house now contains a dramatic high ceilinged kitchen and dining room, WC and luxury garage and store. Then, the oak paneled principle reception room shares the first floor with the guest bedroom, en-suite and study. A high-tech building management system controls hidden technology seamlessly allowing the whole house, audio, TV and data and lighting control as well as remote access to security and climate control. The use of this modern technology in combination with the latest glazing and insulation products not only helps to create a dynamic piece of architecture, but a much more energy efficient home.