Nearly one in four offices in the centre of Perth are empty with the office vacancy rate more than double the national average and at its highest level in more than 20 years.

The office market vacancy rate hit 21.8 per cent in the six months to July, up from 19.6 per cent as the economy continues to splutter due to a slowdown in the resources industry.

Australia’s national office market vacancy rate fell from 10.5 per cent to 10.4 per cent with demand for new office space centred in Sydney, Brisbane, Canberra and Melbourne, according to the Property Council’s half-yearly report.

The new buildings constructed to cater for extra business activity during one of Australia’s greatest ever mining booms are contributing to a surplus of empty offices now that it is over.

Demand has weakened but the news was not all bad for WA, said the Property Council of Australia.

“The good news for this market is that little new stock is expected until late 2018 meaning that from here on it is demand that will drive office vacancy,” the report said.

Sydney and Melbourne continue to perform strongly with vacancy rates of 5.6 per cent and 7.0 per cent respectively.