The project is for the conversion of two single storey flats into one duplex apartment with a central internal lightwell and garden. Living and sleeping spaces are situated around the lightwell, visually connecting them with the sky and one another. How to create a garden/outside space where planning constraints would not allow a roof terrace or balcony, was the dilemma. The answer came in the form of a central, enclosed garden of three levels that sits within the building, surrounded by the living spaces. Designed as an atrium, with a giant opening skylight, the 7 m by 2.5 m space is planted on the lowest “living” level; it includes a swing above; before breaking out onto a roof terrace. The space brings the outside in – a garden ascending through the house. In the summer the skylight above the garden can be retracted to allow fresh air to flood into the property. A white steel stairway built within the atrium climbs from the main living areas to the bedrooms and then further up to the roof. Above the second storey the roof rises by approximately another metre. The skylight is installed at this level. Below this we have installed a metal grid mezzanine, so, when the skylight is fully open, this access deck becomes an outdoor terrace. Open to the sky and bordered on all sides by the roof, it is a totally private space with fantastic views over London: high up and invisible from the road, most of the traffic noise is completely lost. This is a tranquil outdoor space in the heart of the city. photos © Edmund Sumner