A key signal for whether Australia is about to experience its own property market collapse lies in the spike of house constructions, says value investor Roger Montgomery, adding if the United States is anything to go by, we're in serious trouble.

After crunching the numbers, Mr Montgomery says the estimated 18 months local overhang is more than the 12 months oversupply the US had prior to the popping of its housing market bubble.

"It looks like Australia has a greater oversupply problem than the US did in 2007," says Mr Montgomery in a note to clients. "And after their property market collapse, it took five years before property prices began recovering."

Mr Montgomery points to data from the Australian Bureau of Statistics which uses household formation as a proxy for demand and construction as an indicator of supply.