After increasing substantially during the pandemic, experts now predict the cost of building supplies will start to drop.

Master Builders Association chief economist Shane Garrett says prices have peaked after increasing by up to 38% in the year to September 2022.

Part of the problem, according to Garrett, is that speculators bought up big, hoping to sell for huge profits.

But with some supply issues resolved, prices are now starting to drop, so speculators have started to offload.

Perth recorded the biggest price increases in materials, with the cost of a new home up by 31% in the year to September.

Costs rose most significantly for plywood and board (38%), terracotta tiles (33%), window timber (32%), structural timber (31%), timber doors (26.5%), steel beams and sections (26%), mirrors and glass (23%) and reinforcing steel (23%).

MBA head John Gelavis says things which can make the sector more productive include a five-day work week and encouraging more women to join the industry.