To ensure the maximum benefit from the geothermal system, as well as generally reducing

running costs, passive measures were also employed to reduce the heating and cooling

loadings where possible. These included the following-

• the use of skylights and voids to maximise natural daylight penetration into the depths of the building, reducing the level of artificial lighting required; these voids were also a structural issue, with minimal contact between the existing old slab and the new upper floor slab via small ‘bridges’ (see later). The resulting voids allowed for natural light from the roof above to therefore penetrate into the ground floor below.

• glazing to roof lights using Danpalon tinted polycarbonate sheeting to reduce heat gain and loss due to its insulative qualities;

• low-e double glazing to windows and glazed doors, especially along the long street fagade, which faces due east, to ensure minimum solar gain in summer and heat loss in winter, and still providing natural lighting;

• the large glazed face of the upper-floor Council Chambers, with the removal of large areas of single glazing and the space frame awning, has similarly been replaced with low-e double glazing, assisting with solar control as well as the additional benefits of acoustic insulation;

• zoning of conditioned areas, along with air locks provided to main entry to reduce unnecessary heat exchange from air conditioned to external air;

• door seals to high-ventilation areas and external doors, with draught control also to the latter;

• energy efficient lighting, appropriately banked to allow individual switching;

• Verasol insulating blinds to external windows to improve heat loss retention or prevention as needed, but still allowing some daylight penetration;