Is a Performance Solution a loophole?

It’s the opposite. A Performance Solution carries more process, not less: a performance-based design brief prepared with the relevant stakeholders, the analysis, an evaluation against agreed acceptance criteria, and a final report.

The reference-building method does have a history. Before 2019 an older version was used widely, including in WA, and in 2017 it was reported as a way to pass houses well short of the standard. The ABCB tightened it in NCC 2019, barred house energy rating software from it, and in NCC 2022 fixed its operating schedules, thermostat settings and occupancy.

Today the reference house must comply with the Deemed-to-Satisfy Provisions, the calculation method must comply with ANSI/ASHRAE Standard 140, and in climate zones 2 to 7 heating and cooling are each tested on their own.

The question isn’t whether it’s allowed. It’s whether it’s done properly.