The honest answer: $15,000 to $30,000 for a typical single-storey 200m2 Adelaide home replacing tile with Colorbond. Here's what changes the price.
Size matters most
Roof area scales the cost linearly. A 150m2 home is around 25% cheaper than a 200m2; a 300m2 home is roughly 50% more.
Two big multipliers
Asbestos cement removal adds $8,000-$15,000. Double storey adds 25-40% for scaffold.
Material choice
Colorbond is cheaper than new tile and significantly cheaper than slate. Marine-grade Colorbond for coastal suburbs (Glenelg, Henley, Semaphore) adds 10-15%.