A new study has found the median cost of a home in Perth is now seven times the average annual wage.

Ten years ago, a house cost four times the average annual income.

Housing affordability has decreased in every state and territory, and the lobby group Australians for Affordable Housing has launched a national campaign to put pressure on state governments to address this.

The group says the figures, from Canberra University, show young people are being forced out of the property market by tax breaks like negative gearing which favour older people purchasing investment properties.

A spokeswoman Sarah Toohey says the WA government needs to provide more low cost housing.

"What needs to happen now is there needs to be some funding and investment in public and community housing," she said.

"We need the Federal government to work with the WA government and vice versa to help make sure the housing system works."

In May, the WA Government released a housing strategy to build 20,000 inexpensive homes by 2020.

Ms Toohey says the plan is a good start but the government needs to work harder to deliver on its promises sooner and it should be easier for young people to get into the property market.

"People should be able to get housing which meets their needs and for some people that will be rental and for some people that will be home ownership," she said.

"What we'd like to see is a housing system that provides that assistance to people."

The WA Council of Social Service says housing affordability is in crisis.

WACOSS ceo Irina Cattalini says a lack of affordable housing puts a strain on families earning lower incomes.

"If you don't have access to a roof over your head, it's very difficult for families, particularly people with children and for a number of households they are in that crisis situation," she said.

"What we used to have is about six per cent of the total housing stock of WA was affordable housing; that's reduced down now to about four per cent of the total housing stock."



