Well I definitly now think its a good idea to get a building inspection, my friend organised a building inspection on a unit and the building inspection identified damp issues in the under ground car park and garden beds, The inspector said that basically they did not waterproof and almost impossible to fix now as you can't remove soil around the masonary work due to being partially underground, would cost thousands and thousands to repair via a different method (internally) and would be an on-going problem, so I would have to say its well worth getting these inspections done even on units.