The convicts of the First Fleet constructed simple huts using wattle and daub for the walls and bark or thatch for the roof.
Early Australian Architectural History, Sydney Architecture
Wattle and daub, Wikipedia
Slab Hut, Wikipedia
Early Settlers' Homes and Bush Huts in Australia
Colonial Slab Huts of Australia, ANU
Building Construction Practice in the Colony of NSW from the Arrival of the First Fleet, John L. Guy