Requirements vary by local government area and by what you are actually doing, so treat this as orientation rather than advice for your specific job.
Generally needs approval
Removing a building or a substantial part of a structure typically requires a demolition permit from the local council, along with evidence that services have been disconnected.
Generally does not
Internal, non-structural work — pulling up flooring, removing a fit-out, taking out a non-load-bearing partition — usually does not need a demolition permit, though strata and landlord approvals may still apply.
The grey area
Anything structural, anything affecting a boundary wall, and anything on a heritage-listed property. Ask the council before you start, not after a neighbour does.
Who applies
Usually the owner or a licensed demolition contractor acting for them. Confirm who is lodging what before work is booked.
Need this done in Perth?
Tell us the job and we'll give you a straight answer on what it takes.