The underlying goal is to reduce greenhouse gas emissions.
Initially it was achieved by efficiently using energy.
In BCA 2016, this was broadened to also require that equipment use a
low greenhouse intensity energy source.
It should also be noted that the goal is not occupant comfort directly.
The measures are based on achieving an internal environment in which occupants may not always be comfortable, but the conditions are sufficiently tolerable for occupants to minimise their use of services including artificial heating, cooling or lighting.
The energy used over the life of a building has an operational energy component and an embodied energy component.
Operational energy is the focus of the ABCB at this time; broader environmental sustainability measures are being considered by governments.