A sensuous helical stair contained within a top-lit drum links the overlapping upper (entry & living) and lower (sleeping) floors of this 230m2 duplex penthouse; the frameless glass overhead drawing the sky deep into the drum and creating an effect reminiscent of a James Turrell installation. The curving marble-plaster lining of the drum unravels like a ribbon into the 22m long living space, animating the entrance area and enclosing a study (with en suite shower) that doubles as a guest bedroom. The stair leads down to a spacious master bedroom suite with a spa-style dressing/bathing area with a timber bath and wet room shower, a second children's bedroom suite and a utility room. A fire engineered approach to Means of Escape avoided the usual fire doors and lobbies, allowing considerably longer escape distances than normal and thus the large open plan upper floor living space. Winner ‘Best Apartment’ in the 2013 London Evening Standard New Homes Awards.