Exterior Surfaces must be non-slip and must have a minimal side slope
See (Landings)

Interior Surfaces
Non slip floors are essential,
Short pile, antistatic carpet with no underfelt is preferred.

Queensland Housing could have finance available for people with disabilities.

Additionally, a grant of up to $10 000 is available to construct accessible housing or for modifications to bathrooms and kitchens access.

Conditions apply.
Qld Department of Housing. Phone: 1300 654 322