This passive solar new-build house on the edge of the Great Karoo desert in South Africa acts as a poetic and flexible agricultural object, a harvester of light and air, which is adjusted by its inhabitants in response to the changing natural elements. Key elements of the brief were: to bring the inhabitants into a closer relationship with the natural world – the spectacular landscape of the Swartberg and the Karoo – along with changes in light, heat and wind, at different times of day and during different seasons; to focus on passive, rather than active, means to heat and cool the building; and to use local labour and materials which connect with the traditional of building in the Karoo. In the intense heat of summer the thick-walled house can be shuttered, while in winter the large openings act as suncatchers, allowing the dark brick floors to radiate the stored warmth of the sun in cool evenings. The house uses a limited palette of robust materials, which connect to the previous use of the site as a sheep farm – brick-on-edge floors, ash, roughcast limewashed plaster and white ceramic tiles. The day/night, light/dark character of the house is emphasized by large glazed doors, which slide away into roughcast plaster walls, and small scattered openings, which allow shafts of light to penetrate into shadows, and are configured according to the positions of stars in constellations visible from the upper roof terraces. The elevated roof terraces act as modulated raised ground surfaces. They foreground far views of the mountains, and bring the inhabitants closer to the clear, star-filled skies. The shifted geometries of the plan are a consequence of arranging the spaces in response to the surrounding landscape: the volumetrically differentiated rooms are inflected relative to one another in order to capture specific views of the mountains and grasslands. The far views of the Karoo to the north and east are balanced by the rise of the mountains to the south. To the west the house is more opaque, screening out the burning summer light, while the upper terraces allow views to the sunsets, and the town, at cooler times of day and in the winter. The house avoids sophisticated installations for heating and cooling, relying on the fabric of the building – insulated brick walls with a high thermal mass, dark brick floors to retain heat in winter, double-glazed timber windows, high level ventilation into double volumes and sliding timber shutters, to modulate temperatures. The east-west orientation allows the principle spaces to take advantage of the sun from the north, while large openings to the south enable views to the mountains. Responsiveness to the environment is used to develop a poetic and material language for the building. The house becomes inseparable from its context with the positioning and orientation of spaces towards the landscape. It allows nature and landscape to become part of the ephemeral materials of the house.