A slowdown in WA's population growth and a significant amount of newly constructed dwellings coming to completion have created an oversupply of rental accommodation in Perth, with the vacancy rate rising to 4.9 per cent in the three months to May as the number of properties for lease jumps, according to preliminary reiwa.com data.

This is the highest vacancy rate in six years, after it reached 4.8 per cent in the September quarter of 2009. There are now 8,147 homes looking for tenants, up by almost 600 over the last month. Perth’s median rent peaked at $475 per week in the middle of 2013 but has since fallen by $50, or around 10 per cent across the board.

“The competition among property owners is having an effect on price, with the metropolitan median rent dropping by $5 on the March quarter to $425 per week, which represents a cut of $25 on the same time last year,” said President of the Real Estate Institute of Western Australia, David Airey.

“The long term equilibrium for Perth’s vacancy rate is 3 per cent, so the current situation means there are more than 50 per cent more properties on the market than is usual,” said Airey, who called on landlords to ensure properties were well presented and priced right. “Owners need to be realistic about the current market in order to attract and maintain good tenants,” he said.