When reading a 2006 Massachusetts state audit of public housing, lawyers at the Massachusetts Law Reform Institute noticed a concerning figure in the appendix: More than 1,000 of the state’s 45,600 public housing units were sitting empty for more than two months, three times the state limit of 21 days.

“That was a number that made us stand up and look,” said Annette Duke, staff attorney for the institute. Duke partnered with the Massachusetts Union of Public Housing Tenants to bring their vacancy concerns to state legislators. “When we talked to legislators, we could see they were shocked and concerned. [These units] were just sitting there unused, when [we] have a homelessness problem.”

Massachusetts wasn’t the first place to highlight the issue. In 2003, Manhattan Borough President Scott Stringer published a report citing 4,399 public housing units across New York City that had been unoccupied for at least a year. In the report, Stringer proposed to speed up the rehabilitation of public housing by hiring more residents for construction projects and increasing public and private funding. But, according to Stringer’s office, no actual policies or programs were ever initiated as a result of the findings.

But in Massachusetts, the high vacancy number spurred a public-private partnership to address the issue. In the past few years, the Massachusetts Law Reform Institute and the Massachusetts Union have worked with the Massachusetts Department of Housing and Community Development  to craft new policies aimed at speeding up rehabilitation of public housing and keeping a closer eye on local housing agencies as they do it.

Last year, the partnership helped create a $2 million grant program for housing agencies to complete long-stalled rehabilitation projects. The vacancy problem in Massachusetts is primarily a financial one, and many units had been left empty and unfinished when the money ran out.

After winning support from the chair of the Massachusetts joint committee on housing, Rep. Kevin Honan, the grant was created with funding from the state Affordable Housing Trust. In November, 32 public housing authorities across the state received up to $15,000 from the grant, resulting in 200 new units being brought online.

As of April 2012, Massachusetts had 1,265 vacant units, down from 1,606 in 2010. Supporters of the grant are working to preserve its funding for next year’s budget. Administrators at the housing department are also considering a new policy that would scale back operating subsidies for vacant units.

But the real impact of the partnership’s efforts may be increasing oversight and accountability of housing agencies. When it first investigated the issue, the Massachusetts Law Reform Institute found a wide gap between the true number of statewide vacancies and the figure legislators and government agencies had been given. The Boston Housing Authority, for example, hadn’t reported 138 vacancies in its 11,097 units.

The housing department has since upgraded its Online Vacancy System, which requires housing agencies to constantly update their number of vacant and offline units as well as file a quarterly report. Only housing agencies with accurate online reports qualify for the Affordable Housing Trust grant.

“The federal and state government doesn’t know what the housing authorities are doing,” said Jack Cooper, director of the Massachusetts Union. “The tenants have to be the whistle-blower.”

Massachusetts Union is the first statewide organization of public housing residents in the country, a model that has since been copied by several states. Once the Massachusetts Law Reform Institute unearthed the vacancy numbers, the Massachusetts Union rallied tenants to advocate for increased funding.

To get a true sense of the vacancy issue, government officials need only ask the public housing residents who have long lived next to empty apartments and boarded windows. “Tenants see things that the [housing authority] board members don’t,” said Massachusetts Union member Susan Bonner, who has lived in Nahant, Mass., public housing for 50 years. “They really do know what’s going on around them.”