A new, publicly-available database is backing up what many frustrated Massachusetts residents already know: the state's shortage of affordable housing is even worse than previously known.

The data dashboard was released Tuesday by the nonprofit group Housing Navigator Massachusetts, which also runs an online search tool intended to help renters find affordable housing options. The data show that the state has tens of thousands fewer affordable homes than reflected in its official inventory. And the data suggests that some higher-income communities are using affordable housing policies in racially and economically exclusionary ways.

"Incredibly, I think to most people, a simple question like 'how many units of affordable housing does the state of Massachusetts have?' couldn't be answered," said Jennifer Gilbert, executive director of Housing Navigator Massachusetts. "And it's hard to make data driven policy, it's hard to inform conversation, if you can't have that basic set of information about housing across the state and in every municipality."

The new data dashboard includes information from 281 of the state's 351 cities and towns. For each town, the dashboard shows a breakdown of affordable units, including the number of bedrooms and what percentage of units are age restricted. In the remaining 71 communities, Housing Navigator Massachusetts didn’t find any affordable income-restricted rental housing.

The closest thing the state has to an official estimate of affordable units is called the "subsidized housing inventory."

"The subsidized housing inventory is publicly published. You can Google it," said Aja Kennedy, racial wealth gap research fellow at Boston Indicators at a presentation Tuesday morning on the new dashboard. "And for each municipality, it shows the share of that municipality's housing units that are included in the subsidized housing inventory."

But it's also a gross overcount of what's available, according to the new dashboard.

One problem, Kennedy explained is that in buildings that include both affordable and market rate units in order to meet the requirements of the state's 40B statute, the official inventory also counts the market-rate units.

Under the 40B affordable housing statute, developers can override local zoning ordinances to build higher density projects if less than 10% of the housing stock in that community is considered affordable.

Kennedy said her analysis showed about 34,000 fewer affordable housing units than listed in the official subsidized housing inventory.

The data also show how affluent Massachusetts communities are excluding families of color by reserving affordable units for seniors, said Katie Einstein, Urban-H Index associate director of housing at Boston University.

"There are 44 communities in Massachusetts that have produced affordable housing that is 100% age restricted," Einstein said in her presentation Tuesday morning. "Those communities tend to be overwhelmingly white."

White communities that are surrounded by other white communities are less likely to attach age restrictions to housing, Einstein said.

"In contrast, if you are a white community and you are surrounded by communities with a disproportionately high Black population, you are significantly more likely to have an age restriction on your subsidized housing," she said. "I would argue that these findings suggest that, in the aggregate, the way that age restrictions have been applied in Massachusetts, present serious fair housing concerns."

To housing advocates like Felix Jordan, the challenges illustrated by the data are not surprising. Jordan is a community organizer and housing advocate at the Boston Center for Independent Living.

"I've seen a lot of stories behind these numbers," Jordan said. "Thinking about all of the consumers I work with that are like, 'they say these units are out there. I'm not seeing them, I'm not getting them.' So it's interesting to have that sort of data piece behind what we've been hearing for a while."

Updated: January 31, 2024
This story was updated to clarify that the analysis covered all Massachusetts communities, but that 71 of those municipalities did not show an indication of having any affordable rental housing.