The brief was to combine two penthouse flats, in this former Grade II Listed hospital, into one large family flat with a central showpiece stair and surmounted by the original 1870s cupola. Within the constraints of the conservation demands large, glazed, fire-resistant screens were added to leave the space full of light and long views whilst being acoustically subdivided into rooms. A study mezzanine was added at purlin level accessed by a stair combined with a bookcase. The cupola which originally was just a ventilation device had its wooden louvres replaced by glass ones and with openable windows behind so as to flood the stairwell with daylight. A glass and steel spiral stair was designed to go up into this cupola to give fine views over central London but was deferred while the client had very small children.