The National Construction Code (NCC) is a uniform set of technical provisions for the design and construction of buildings and other structures throughout Australia.

The NCC energy efficiency provisions require a dwelling and its domestic services to use energy efficiently in order to reduce energy consumption, reduce greenhouse gas emissions, improve occupant health and amenity, and improve the resilience of a building to extreme weather and blackouts.

The NCC 2022 residential energy efficiency provisions introduce a whole-of-home (WOH) approach. This provides a holistic assessment of the energy performance of a dwelling, covering both thermal performance and domestic services.

To meet the WOH requirements, the net equivalent energy usage of a dwelling must not exceed a certain allowance.

The net equivalent energy usage of a dwelling is calculated by multiplying the applicable WOH efficiency factor by the applicable floor area factor, adding swimming pool and spa pump energy usage, and subtracting the installed capacity of any photovoltaics (PV). The applicable WOH efficiency factors are determined by the combination of the domestic services (i.e. heating, cooling and heated water equipment).

Section 2 of this ABCB Standard contains the WOH efficiency factors used in the formula for calculating net equivalent energy usage in J3D14 of NCC Volume One and Part 13.6 of the ABCB Housing Provisions.