The nation's treasurers have agreed to develop a new way to encourage investment in affordable rental and community housing, but the Commonwealth is still resisting calls to change tax concessions.

Federal Treasurer Scott Morrison signed off on the development of a new financing model at a meeting with his state and territory counterparts in Canberra.

It will be designed to group together financing requests to generate more investment at cheaper interest rates.

"One of the challenges that is faced by those developing affordable housing is access to longer-term, affordable finance," Mr Morrison said.

"The access to capital is a critical issue for that sector and this would involve the states and Commonwealth working together to act as a bond aggregator to put finance into those developments."

Mr Morrison's focus on rental affordability has been welcomed by the peak body, Homelessness Australia.

"The sorts of devices being discussed to stimulate housing investment at the low end of the market are all the sorts of things we need," Homelessness Australia chairman Jenny Smith said.

"But they're not a magic pudding — they are going to need government support and government investment to work."

The model was recommended by an affordable housing working group, which has also called on Governments to consider other ways to improve affordability and supply, including changes to zoning and planning rules, and taxation and other concessions.

Despite calls from some states to consider winding back negative gearing, Mr Morrison said the Federal Government would not revisit it.

"It is the Government's view that the mum and dad investors, who actually provide the capital for the nation's rental housing stock, if we were to withdraw that, then that has the only outcome of increasing rents," Mr Morrison said.

Homelessness body calls on Government to reconsider negative gearing

That view is echoed by the chief executive of Master Builders Australia, Wilhelm Harnisch, who said negative gearing was not just suited to Sydney or Melbourne.

"Negative gearing provides rental properties in regional and rural towns, where those workers who are mobile, and want to move around, have affordable accommodation," Mr Harnisch said.

He welcomed the policy focus instead on new finance models for affordable housing.

"You can't fix housing affordability if you don't talk about it, yes some ideas will be contested, but it's important that those matters do get raised and properly contested," Mr Harnisch said.

But Homelessness Australia said the Government should reconsider negative gearing.

"Ninety-three per cent of them are purchasing existing properties, they are not adding to the supply of housing which is part of the solution," Ms Smith said.

"They are literally competing with first home buyers which means first home buyers are renting down, they are renting the properties that those on the lowest income need to be able to rent to put a roof over their heads."

Morrison eager to help in the fight against homelessness

The treasurers' meeting also discussed the $115 million partnership agreement between the Commonwealth and states and territories which funds critical homelessness services.

The current agreement expires mid-2017 and Ms Smith said they were anxiously waiting for an announcement about the next agreement.

"There is no reason for the Government not to reassure the sector right now that that money should be there," she said.

"Not just to continue that funding but to index it and give us some surety for the next five years."

Mr Morrison said the Government would make an announcement about the next agreement when it is in a position to do so.