The main living spaces occupy the upper floor and contain the entrance hall, kitchen, dining area and main living room under a metal ‘butterfly’ roof. This roof is separated from the enclosing rendered walls by clerestorey windows allowing all available sunlight to be captured. The tall south-facing windows at this level allow maximum sun penetration to provide passive solar heating. The house under-floor heating system, fed by a ground source geo-thermal pipe-work system, is normally required only to provide a low level of background heat. The windows may be shielded from excess sun and from over-heating of the interior by motorised canvas awnings, which also provide shelter, from rain, wind or sun, or for people to use the adjacent large terrace. The areas of glazing maximise the use of natural day- and sun-light, augmented at night by low-energy artificial lighting.