From the outset, one of the main design aims was to limit the amount of energy the house would use throughout the year using 'passive' means without necessarily resorting to potentially expensive lowenergy additions like solar panels and photovoltaic tiles.
In the winter, loss of heat is minimised by using 200-250mm of insulation in the walls and roof. The glazed sunspace on the south side of the house is closed off from the heated rooms and effectively acts as triple glazing, while any useful winter sunshine is allowed into the house providing free heat. Enough daylight enters the rooms from the south, so the windows on the north side can be small, again limiting heat loss. Effectively, the house is facing the sun.
The stainless steel fireplace chimney runs up through the heart of the house, providing useful free heat to the upper rooms. A large proportion of the heating need will be provided by the lights and the people inside, but a small gas-fired condensing boiler provides any heating that is needed, using underfloor heating.
In the summer, the rooms of the house can be opened up to the double-height sunspace which can be opened at the top and the bottom to provide fresh air and keep temperatures down on hot days. The air inlets at low level draw air from the cool, shaded undercroft below the building, which helps to pre-cool the incoming air.
Rainwater is collected to water plants in the sunspace, reducing reliance on water from the mains.