Extending that to a standard 20 per cent deposit would take several years, unless the couple can get a kick-start from their parents.
"Really I think a 20 per cent deposit, unless you receive a financial windfall or you have an extremely well-paying job, you both have extremely well-paying jobs, it's really not achievable for first home buyers," Ms Davies said.
A Sydney man would have to save 70 per cent of his income and a woman 98 per cent. Ms Davies said Sydney is by far the most challenging market for first home buyers to break into, followed by Melbourne.
But even elsewhere it would probably take about five years to save a 20 per cent deposit, she said.
"If you were determined to save a 20 per cent deposit and you were wanting to buy in Sydney particularly or even Melbourne and you're on an average income, then I think in order to pay your other expenses you're going to be looking at at least six, seven, eight years to get a 20 per cent deposit," Ms Davies said.
A couple on average incomes would have to save 29 per cent of their net pay towards a deposit in Melbourne. In Brisbane it is 26 per cent, the Canstar research shows.
Ms Davies said that was probably a more sustainable amount to be able to put aside but it would still be difficult on an average income.
- AAP