Forever if you really wanted. A property close to my parents home, when they moved there in 1975, was burnt down. The block has remained vacant ever since (well there is a garage there)
I think the owner (who lives down the road), stores his stuff inside and has a veggie patch out the back. The block would have to be worth around $900k
When I was looking for my PPOR in 2002, I looked at house & land package in Craigeburn (3064) but the condition was to build the house on the land within 12 months (not sure the condition was required from the council or builder)
Buzz, the land you mentioned located in inner suburb ?