Glasswool Batts
The default bulk insulation: non-combustible to AS/NZS 1530.1, Australian made with a high recycled glass content, friction fits between studs and joists, and the cheapest way to reach a given R-value where depth is available.
Modern glasswool is bio-soluble, but it still itches during handling. If that rules it out for a job, look at polyester. Delivered across Victoria and New South Wales.
