Our home here in Australia is not brick, can we still add another floor?

This is governed by local building laws. You need to go to your local building department and inquire or speak to a local architect.

can we still add another floor? yes! This is doable. However, to find out if it's permitable follow ScottGems instructions. Good luck, Tom

Is your home built on a slab or a footing? The foundation frequently determines if a second floor can be added.