It was among the largest worldwide falls and compares with a 7 percentage point fall among young Aussies in the top 20 per cent of income earners.
In Australia there has been a decline in homeowner ship rates across every generation for the past 40 years.
But it is most prominent among the country's lowest income earners.
And the OECD - which represents leading economic nations - warned the situation for poorer younger Australians is likely to worsen in coming years.
The OECD - a France based think-tank - urged an overhaul of tax policies and increased housing supply in member countries to improve housing affordability.
"In the face of unprecedented housing market challenges, it is more important than ever to ensure that housing taxes are both fair and efficient," OECD's centre for tax policy director, Pascal Saint-Amans, said.
The OECD study took a swipe at Australia's capital gains tax exemptions, under which there is no capital gains tax on a person's principal place of residence.
It suggested capping tax exemptions to ensure the "highest-value gains are taxed" and boosting government coffers.
But reforming capital gains tax in Australia has proved a political hot potato.
When it was in opposition, Labor proposed ending the 50 per cent capital gains tax exemption for investors in property and other assets.
The policy was later dropped.