Even as tower cranes puncture Australia’s urban skylines and nailguns echo across the suburbs, a crisis threatens the nation’s ambitious housing targets.

Behind the hoardings of construction sites lies an industry in productivity freefall—delivering half the housing per labour hour it once did, with costs soaring ever upward.

According to Productivity Commission chair Danielle Wood, value output per worker has dropped from $1400 an hour in the late 1990s to just $500 an hour today.