When Aroha Ngata first proposed a passive-house standard for a new Hamilton primary school, the board was sceptical about the cost.
Four years on, the school uses less than a quarter of the heating energy of a typical classroom block, and the build came in within two per cent of a conventional design.
"The biggest lesson was bringing the builders in early," Aroha says. "Airtightness is a team sport."
Aroha Ngata is a fictional member featured on this demonstration site.