This Verification Method allows the use of the modelling protocols and schedules of the National Building Environment Rating System for energy efficiency (known as NABERS Energy) to demonstrate compliance with J1P1 for Class 5, Class 2, and Class 3 buildings, and Class 6 shopping centres. NABERS Energy has a well-established energy modelling framework, which is used primarily to benchmark a building’s energy use against a 6-star scale based on its actual energy consumption over a 12-month period. However: 

For a Class 5 building: under J1V1 compliance is shown when an energy model of the building design predicts the energy consumption to be less than 67% of 5.5 stars on the NABERS Energy for Offices base-building scale. 67% of 5.5 stars is roughly equivalent to a 6-star NABERS Energy rating.

For Class 2 buildings (other Than sole-occupancy units): under J1V1 compliance is shown when an energy model of the building design predicts the energy consumption to be less than 90% of 5 stars on the NABERS Energy for Offices base-building scale. 90% of 5 stars is roughly equivalent to a 6-star NABERS energy rating.

For Class 3 buildings: under J1V1 compliance is shown when an energy model of the building design predicts the energy consumption to be less than 70% of 5 stars on the NABERS Energy for Offices base-building scale. 70% of 5 stars is roughly equivalent to a 6-star NABERS energy rating.

For Class 6 shopping centres: under J1V1 compliance is shown when an energy model of the building design predicts the energy consumption to be less than 80% of 4.5 stars on the NABERS Energy for Offices base-building scale. 80% of 4.5 stars is roughly equivalent to a 6-star NABERS Energy rating.

All the above buildings must also comply with any additional requirements specified in Specification 33 and the calculation methods must adhere to ANSI/ASHRAE Standard 140.

In addition to the energy model, the Verification Method requires a NABERS Energy for Offices base-building Commitment Agreement to be obtained. This ensures that the necessary rating has been verified through the NABERS Energy process, committing to the design being followed through to the building’s operation.

The different targets set for the Commitment Agreement and energy modelling recognises that it is common industry practice to commit to a lower NABERS Energy rating than is likely to be achieved. This is to allow for factors outside the control of the designer relating to the building’s operation, which can impact on its ability to achieve a higher rating.

To ensure that occupant comfort is not compromised in the pursuit of energy efficiency, an assessment of the Predicted Mean Vote (PMV) is also a requirement of the Verification Method. PMV predicts the occupant comfort of a given design. The calculation of PMV uses much of the same information that is used in the creation of energy models. The PMV must be achieved across not less than 95% of the occupied floor area for not less than 98% of the hours of operation.

The PMV metric is designed for fully mechanically ventilated buildings. In situations where a building uses mix-mode or naturally ventilating air-conditioning systems, the Adaptive Thermal Comfort metric may be more appropriate. This can be used as a Performance Solution subject to the approval of the building regulatory authority. Adaptive Thermal Comfort can also be used in combination with PMV in buildings that have both fully mechanical and partially naturally ventilated spaces.

To demonstrate compliance, it is suggested that the equivalent result produced by an Adaptive Thermal Comfort Model should be not less than 80% acceptability achieved across not less than 95% of the floor area of all occupied zones not less than 98% of the hours of operation of the building. Note, this is likely to be appropriate for buildings that meet the applicability criterion in Section 5.4.1 of ASHRAE 55-2013.