It is the first detailed election initiative of the campaign for the Greens, who may yet again find themselves in a balance-of-power position in the expanded Legislative Assembly.

The Greens say they would make all new homes in Canberra meet a new design standard, known as the liveable housing design silver level, which ensures buildings are accessible for ageing residents and those with a disability.

The policy is yet to be costed, but the Greens say they will submit it to Treasury during the election costings period.

The Master Builders Association said the design principles were positive, but warned they would almost certainly add to the costs of building homes.

Executive director Kirk Coningham said governments must avoid adding to building costs at a time when free-standing homes were already almost out of reach of the average first home buyer in Canberra.

"The MBA is fine with the design principles, but as a guiding principle today in the ACT, we've got to be ultra cautious of adding any cost onto a new home,' he said.

But Greens housing and homelessness spokeswoman Veronica Wensing said there was a major shortage of accessible homes in the ACT, and that including accessible design at construction phase was much cheaper than retro-fitting.

"What we know is that its actually 22 times more efficient to include these liveable housing design features at the point of construction, than it is to retrofit," she said.

The Greens' policy would establish a transition plan to ensure all new homes meet the accessibility standards by 2020.

They would also develop training and transition programs for architects and builders, and provide government housing projects for people with specific needs.

The Greens have already announced housing affordability measures during their campaign launch last month.

Leader Shane Rattenbury, who is seeking re-election in Kurrajong, said the party would seek to dedicate government land to affordable housing, and introduce a "Nightingale Housing Model", which capped returns to investors, involved buyers in decision-making, and gave architects the lead, rather than developers.

Neither Labor or the Liberals have announced their housing policies at this early stage.

Earlier this year, Australian Council on Social Services ACT director Susan Helyar said Canberra still lacked a proper solution to housing accessibility for ageing residents and those with a disability.

Ms Wensing said there was a 60 per cent chance that a home would be occupied by someone with a disability at some point.

"The need for housing with universal design standards is only going to grow," she said.

"Now is the time to put the community first, and make sure everybody can find housing that suits their needs."