At least 20,000 new social houses are needed over the next decade to deal with growing numbers of homeless, a new reports warns.
And although the Government has pledged it will build 5000 to 6000 social houses over the next decade, to help provide more Kiwis with a home, a just-released Salvation Army report indicates this may not be enough.
Its report Taking Stock showed the growing number of people on a benefit, combined with an increase in "poorer" Baby Boomers, aged 65 and over, with no permanent home would continue to put pressure on already limited stock.
There are more than 82,000 social houses in New Zealand - of which 62,500 are owned or managed by Housing New Zealand, 12,000 by local councils and 8000 by other agencies.
The report's author, Alan Johnson, said between 2000 to 2500 new houses each year was a conservative estimate of what was needed. Half of these would be needed in Auckland.
The estimated construction cost of between $800m and $1b annually was not unreasonable given the "urgent importance" of addressing the rising levels of homelessness and the high social cost this could incur, he said.
"The proposal should be seen as the bare minimum necessary to ensure that New Zealand's homelessness problems do not worsen."
Johnson said an analysis of Government statistics showed an "enduring number of people living on working-age welfare benefits" and those with limited means aged 65-plus that would only see more people in need of a home.
Data obtained through the Official Information Act showed the number of people on the social housing register had almost doubled in the past decade, and 5353 were on the Ministry of Social Development list in June this year, up from 2737 in the 2006-07 financial year.
Meanwhile the number of houses in HNZ stock had declined by 4582 across the same time period - from 67,063 in the 2007-08 year, to 62,481 in March this year.
Answers to written questions raised by the Green Party in Parliament showed 2539 HNZ homes had been built since 2009, but taking into account 2414 demolitions, it had only added a net 125 new houses to its stock.
This year a new building programme promised to build a total 34,211 new homes - including a net 5000 to 6000 new social homes.
Minister for Social Housing Amy Adams said the Government was running the largest housing project since the 1950s by building 34,000 new homes over the next 10 years in Auckland.
She said they helped close to 9000 families a year find a safe place to stay while they get back on their feet and emergency housing was also available.
"Our social housing reforms are working for those in need. We've changed a system that was focused on simply providing a house, to one that is providing better tailored, wraparound support to help people get back on their feet, while also increasing overall supply."
A partially Government-funded programme, Housing First, had also recently been launched that had so far seen 150 homeless people moved off the streets and into a home within four months.
But Green Party social housing spokeswoman Marama Davidson said more was still needed.
She was confronted daily in her community by the need for secure, warm and dry homes.
"We've always said for several years now that selling off state housing at a time when homelessness in our country is the highest it has ever been, and is climbing, is the worst thing that we could be doing as a country."
She said people continued to tell her it was tough making ends meet in today's climate.
However, Johnson said that simply building more houses may not be enough.
He said it "does not follow that state housing is the only answer and that all the state's resources for housing should go into buying and building state-owned housing".
He suggested alongside more homes, additional support, such as accommodation supplements to help low-income people get into a good quality private home, could help.
At the very least, Johnson called for greater political understanding that social housing could be "for life".
"Until there is some acceptance that there is a permanent and growing demand for social housing, as a nation we are unlikely to fully appreciate both the commitment we need to give to such housing and the potential it has to materially improve the lives of the most vulnerable."
Neither the Ministry of Social Development or Minister for Social Housing responded to requests for comment last night.