Rent inflation in the regions escalated to a "remarkable" 12.4 per cent in the year to August 2021, a new report from the University of New South Wales and the Australian Council of Social Service says.

Nationally, the figure compares to increases accelerating to over 8 per cent by the third quarter in 2021, the fastest rate for well over a decade and well ahead of wage growth at 1.7 per cent, the report says.

Using regional Victoria as an example, the report says the proportion of tenancies affordable for low-income households declined from 41 per cent to 33 per cent in the year to the second quarter of 2021.

"Private rental supply fell by 6% in 2020-21 in regional NSW and by 15% in regional Victoria," it says.

And the situation is expected to get worse with changes to the National Rental Affordability Scheme, ACOSS warns.

The program has funded 38,000 newly built rental homes, rented at 75 to 80 per cent of the market rate.

Over the next three years, rent restrictions attached to some 22,000 of these affordable homes will expire, CEO Cassandra Goldie says.

More than 155,000 households are registered on social housing waiting lists across the country.

While state governments have done a good job responding to homelessness during the pandemic, the shortage of affordable housing means resources committed aren't enough, Dr Goldie said.

Four state governments announced significant social housing construction programs as a component of post pandemic stimulus, adding up to nearly $10 billion over the next few years, the report notes.

"We need the Federal Government to step up and step back into this space and do some heavy lifting to both address the massive social housing shortfall and meet the future needs of a growing and ageing population," Dr Goldie says.

The pandemic proved governments can "move fast to provide short-term temporary accommodation to rough sleepers while boosting investment in affordable housing", Mission Australia CEO James Toomey said.

""Alone, our States and Territories simply don't have the resources to address Australia's social and affordable home shortfall," he says.

"We need a national plan to end homelessness where the Federal Government takes a lead role in investment and that can also leverage private investment to create significantly more social and affordable homes."

ACOSS wants capital funding to build 20,000 new social housing dwellings, a 50 per cent boost of the Commonwealth Rent Assistance payment and a new investment scheme to support construction of affordable homes.

Labor has pledged to establish a Housing Australia Future Fund in government which will build 30,000 social and affordable homes across the country over five years.

Australian Associated Press