A keynote with Joost Bakker, addressed to builders. Australia generated 29 million tonnes of construction and demolition waste in 2022-23, two of every five tonnes the country throws away. The answer put to the room was to build with what farmers already grow. GreenhousebyJoost wraps a steel frame in straw wall panels, a wicking-bed green roof and, next, hemp joinery board pressed at Benalla. The talk covered what this means for a builder's crew and budget: components arrive numbered, local trades assemble them, and Woodleigh School finished its entire build program on eight skip bins.