The not-for-profit group My Home in Canberra, which proposed the initiative in 2013, said the ACT government needed to act with greater urgency to provide basic human rights for people with mental health problems who are homeless or at risk of homelessness.

President John Tucker said the provision of supportive housing was sidelined by the government again.

"They have not designated any specific money for My Home," Mr Tucker said of the recent ACT budget.

"It is very disappointing.

"I think it is a government responsibility to ensure that people with serious and enduring mental illness are provided with adequate accommodation and care, but there are thousands of them who don't get that."

The My Home in Canberra project is set to be built on donated land opposite the shops in Curtin. It is based on Home in Queanbeyan, a successful, community-run facility.

The project was nominated as one of importance in the 2016 Labor/Greens parliamentary agreement.

With that in mind and in anticipation of funding, the committee has put hundreds of hours of work into preparing a project plan, developing a funding model, preparing a draft model of care and reaching out to the community for help in the building process.

The strategic plan prepared by the My Home committee outlines a goal to have the facility, set to cost $6.5 million to build, finished by March 2019, subject to funding.

In his budget submission, Mr Tucker called on the government to "allocate essential capital funds" to ensure they could build the promised facility.

The government allocated $350,000 in the 2017-18 budget for a feasibility study into long-term accommodation and future support requirements for vulnerable people in the ACT with high and complex needs.

"We're trying to come up with a solution to remedy the problem," Mr Tucker said.

"We think if the potential residents are provided with good accommodation and quality care, there would be significant economic, social and health benefits from introducing this particular model," he said.

"But it has been ignored."

Minister for housing Yvette Berry said the budget money would help determine the most appropriate long-term accommodation and support requirements for residents and "will consider models such as My Home".

"Work is already progressing on a project plan for the study," the minister said.

"There is a great level of community interest in progressing work to support housing solutions for people with complex needs."

She said there would be "comprehensive public engagement", which would help inform the decision in the lead up to the ACT Housing and Homelessness Summit, to be held in October.

Greens MLA Shane Rattenbury noted the importance of the project, and said he was pleased preliminary works were funded in the budget.