If termites have infested a building it not necessarily a death sentence for the building. A very large percentage of the time the termite damage is very minimal. It is highly likely that there will be concealed termite mudding and possible concealed termite damage. It is critical that if termite activity is found that the termites be treated immediately to prevent further damage.
There are about 300 different types of termites in Australia which will cause different levels of damage ranging from microcerotermes turneri termites where significant damage to timbers in buildings is rare to Mastotermes darwiniensis, (giant northern termites) which are very destructive to timbers in buildings. These are subterranean termites which need to have contact with the ground.
The other type of termite is the drywood termite which does not need to have contact with the ground and has small colonies and causes damage to the pine floors and pine wall boards, and pine timber parts to the old Queenslanders.
Qcon Building Inspection work in conjunction with Tactic Pest Control https://www.tacticpestcontrol.com.au/ to carry out building and pest inspections. There are always two people onsite carrying out inspections. Bob Gillis does the building inspection and Tactic Pest Control does the pest inspection working together to give a much thorough inspection. Some building inspectors do both inspections with only one person carrying out the building and pest inspection at the same time. You may think this is more efficient but 4 eyes are better that 2 and the pest inspectors main role onsite is to detect termites and not check doors and windows.