During the design process, it took little to convince the Council to utilise the new and different technologies and ideas. After justification of the benefits, as well as invariably the payback, they were able to see the value in these decisions and agreed with the choices made. This was particularly applicable to the WaterFurnace Geothermal system, which has a 4.03 year payback, and a 37% saving on life cycle costing (refer Tables 1 & 2).

Table 1 — Simple Payback Analysis

The principle of the Geothermal system is a simple heat exchange system. An underground loop is filled with water and sunk down into the ground. In this case, 38 bore holes, some 94 metres deep, sunk into the ground external to the building and now hidden under landscaping, provide the necessary ground loop to run the system, while the pumps are housed in an existing area which became an external pump room.

As the earth’s temperature is a constant 15-20 degrees C once past a depth of approximately 2m, the water in the pipe exchanges heat with the ground temperature depending on the current conditions. It is via the pipe that heat is dissipated when cooling in summer, and heat is absorbed when warming the building in winter. The energy then required to bring the temperature up or down to the desired range is significantly reduced. Thus in winter, the heating system gets say a 145 degree boost if the outside temperature is only 0 C whereas the underground temperature is already at 15. Similarly, in summer the cooling system is able to unload the hot air into 15 being the underground temperature, instead of sat 35 — being the outside temperature. On average, the energy saving amounts to a 400% efficiency — ie for every kW pumped into the system, there is a 4kW return.

Issues of accessibility and security were also part of the brief, and both have been resolved to the mutual benefit of all users. External disabled access has now been provided, and all doors into publicly accessible areas are wide enough to accommodate wheelchair usage. Disabled toilets have been included with the facilities, and a small lift provides access to the upper floor.

Security between public and non-public areas was high priority, but without the sense of ‘loosing’ the rest of the building, and the benefits of the voids. One solution has included a separation between the two areas being divided with a glass display cabinet, allowing light to filter through without compromise to security.