The clients were keen to implement sustainable design principles in a house with a flexible layout for family and guests. They wanted an elegant, under-stated house with a relaxed feel.
It is in an established city-fringe neighbourhood and adopts the scale of its neighbours and the weatherboards, but the double height entrance gallery at the middle of the simple C shape gives a striking new design focus. The house faces due north and a bank of solar tubes occupies the gallery roof. Polished concrete floors on the north and west act as heat sinks, and the stack-bonded concrete blocks in the gallery act as a conservatory/trombe wall. Mini-corrugated iron inside and outside the gallery conceals more trombe walls.
The gallery is a transition space between the east and west wings, as is the exposed concrete, glass-balustraded bridge. The house provides a range of living spaces and private areas for family members. The guest bedroom downstairs doubles as a library/extended living room. Tall sliding doors enable flexible uses of adjoining spaces. Openings at each end of the gallery and bridge through the adjacent rooms allow vistas that underscore the east-west axis.
The broad plywood stair rises up within the mass of the block work at the middle of the ‘C’. Cork floors and sustainably-grown Fijian Kauri doors and European beech acoustic ceilings tone with the recycled timber floor areas (from the previous house), the former weatherboards (reversed to be architraves) and floor joists fashioned as handrails.
The upper storey monopitch roofs have skillion ceilings to exaggerate the framed views of the harbour and hills; the large eaves provide summer shading. At the southern rear of the house, the lean-to roofs drop the scale close to the neighbour and are shed-like corrugated steel. The house was designed without the need for resource consent.
Wide wall framing provides deep window reveals and the space for extra insulation. As future proofing for the owners’ old age, a lift shaft connects the basement garage with the ground and first floors – and to a roof deck for 360° views. Clerestory windows at the roof deck admit sun to the southern spaces.
The design used the previous large north-east-facing deck as a starting point. The house is placed to provide sheltered sitting areas. Trees retained with other planting from the previous garden define the outdoor spaces. The grey water system feeds the vegetable patch and rainwater tank reserves for summer watering.
The solar tubes heat a large hot water cylinder supplemented in winter by a wood burner (burning recycled timber!) located in the heart of the house – the blue kitchen. Under-floor water pipes distribute heat to the zoned concrete floor areas. In summer, excess heat is sunk via pipes in an excavation beside the subterranean garage.