Australia's property prices have looked bubbly for a while, but the surge is likely to hit a wall soon amid a combination of few births, high mortality and sparse migration, Goldman Sachs said.

"We estimate Australia's population will likely be 260,000 smaller by the end of 2015, 410,000 smaller by the end of 2016 and 530,000 smaller by the end of 2017," Goldman said in a note Wednesday. "We change our estimate of demographic demand for housing from a 140,000 underlying deficit for established homes by the end of 2017 into a 75,000 underlying surplus."