In relation to a building, means the energy from a network utility operator or a depletable resource (measured in kilowatt-hours per square metre of floor area and per degree-day, and calculated using the Building Research Association of New Zealand's Annual Loss Factor Design Manual 1990 or some other method that can be correlated with that manual) needed to maintain the building at a constant internal temperature for the period from 1 May to the close of 31 August under the following standard conditions: (a) a continuous temperature of 20°C throughout the building: (b) an air change rate of 1 change per hour or the actual air leakage rate, whichever is the greater: (c) a heat emission contribution arising from internal heat sources for that period of 1000 kWh for the first 50 m2 of floor area, and 10 kWh for every additional square metre of floor area: (d) no allowance for (i) carpets; or (ii) blinds, curtains, or drapes, on windows: (e) windows to have a shading coefficient of 0.6 (made up of 0.8 for windows and recesses and 0.75 for site shading