New Subsidized Housing Inventory Figures Provide an Estimate of Affordable Housing Available in each Massachusetts Community

New Subsidized Housing Inventory Figures Provide an Estimate of Affordable Housing Available in each Massachusetts Community

While the new SHI provides important information about the state’s progress toward greater housing affordability, the picture remains incomplete.
Written by Tim Reardon, Data Services Director

August 4, 2023 - The Executive Office of Housing and Livable Communities (EOHLC) recently released new figures on the official Subsidized Housing Inventory (SHI) for each city and town in Massachusetts. The SHI is an important product because it provides a standardized estimate of affordable housing available in each community, and it is used for determining compliance with Ch 40b, the Comprehensive Permit Law. Municipalities with less than 10% of their housing eligible for inclusion on the SHI may be subject to development proposals that can circumvent local zoning if 20-25% of the units have affordability restrictions.   

The release was the first such tabulation to use the recently-released counts of year-round housing units from the 2020 Decennial Census. (Since 2011, the SHI has used Census 2010 housing unit counts.) This release was highly anticipated because the new housing unit counts (the denominator for the percentage calculation) may change which municipalities are above or below the 10% threshold. The new SHI also provides a measure of affordable housing production or loss across the state. The data show that 71 cities and towns across Massachusetts are above the 10% threshold.  Here are some other key findings from MAPC’s first look at the new SHI:  

  • Eleven municipalities statewide dropped below the 10% threshold: Acton, Concord, Cohasset, Easton, Haverhill, Holbrook, Natick, Malden, Reading, Randolph, and Salisbury. These eleven cities and towns are now subject to comprehensive permits unless they satisfy other statutory tests such as land area used for affordable housing or housing planning and production activity. Also dropping below 10% was the state of Massachusetts as a whole: the calculated statewide SHI percentage dropped from 10.1% SHI units to just 9.7%.  
  • Six municipalities are now above 10% in the new data: Bolton, Great Barrington, Norton, Peabody, Wenham, and Wilmington. While all of these saw an increase in their year-round unit count with the new census data, they also recorded 50 to 450 new SHI-eligible units since the December 2020 tabulation—enough to push them above 10%. 
  • 76 municipalities saw a net decline in the number of SHI-eligible units since the last tally in December 2020, with a collective net decline of 2,287 SHI-eligible units, largely due to the expiration of affordability use restrictions. Salem, Weston, Winthrop, and Acton all saw more than 150 SHI-eligible units fall off the rolls. In Reading and Randolph, the loss of SHI-eligible units contributed to their falling below the 10% threshold.  If they had maintained their December 2020 inventory of SHI-eligible units, they would have remained above 10% even with the new Census unit count. However, the loss of just a few dozen units (38 in Reading, 26 in Randolph) was enough to knock them down to less than 10%.  
  • According to the Census Bureau, Massachusetts added about 195,400 year-round housing units from 2010 to 2020. Between the May 2011 SHI (the first to use 2010 census data) and the new tally released on Friday, the state added 34,600 SHI-eligible units, about 17.7% of the total housing unit increase.  

While the new SHI provides important information about the state’s progress toward greater housing affordability, the picture remains incomplete. Not every unit eligible for the SHI is actually deed restricted, and the inventory does not include information about the range of incomes served by the affordability restrictions that do exist. Nor does the SHI include the precise location of developments with affordable housing, information essential to planning for climate resilience, heat mitigation, transportation equity, and other municipal services. 

Legislation currently under consideration at the State House would help provide a more comprehensive picture. An Act Improving Municipal Access to General Existing Housing Data (IMAGE HD, H.1359 and S.856) would require EOHLC to create and make available a database that includes detailed information about the number of units with affordability restrictions, the expiration date of those restrictions, and the location of all SHI-eligible developments. Moving forward, EOHLC would also be required to collect and publish information about income limits, bedroom counts, and square footage per unit at each new development. All of this information already exists in permitting documents, but it is not yet available to planners, advocates, and stakeholders. Other tools and legislative levers are also being developed or considered that could help paint a more comprehensive, useful snapshot of our state’s affordable housing inventory in finer-grain detail. 

Access to more detailed data on a community’s existing affordable housing stock will build a better understanding of local housing affordability challenges and gaps. This data will empower municipalities to more strategically pursue development that can expand affordable housing to meet local needs, preserve existing affordable housing with term-limited deed restrictions, and implement policies and programs to better serve the residents of these developments. The Legislature should move quickly to adopt IMAGE HD so that we all have a better picture of affordable housing in the Commonwealth. 

To find the new SHI data (and historical releases) for your community, visit the MetroBoston DataCommon