A fifth of all housing units in Boston have some type of income restriction placed on them, according to a new city study that officials are calling a crucial part of their efforts to create more affordable units in neighborhoods where they’re needed most.
The study found that of the city’s 54,247 income-restricted housing units – 20 percent of the total housing stock – 66 percent were restricted to households that earn less than 50 percent of the area median income, or $43,150 for a two-person household.
Of that 66 percent, 20,746 units, or 38 percent, are restricted for households making 31 to 50 percent of the area median income, or $25,900 to $43,000 for a two-person household.
The study does not address non-restricted units that are being rented at or sold at market-rate prices, which has led in many cases to increased rents, gentrification of neighborhoods, and a citywide affordable housing crisis.
But officials said the review, the first of its kind, provides a analysis of the city’s housing stock and provides insight as they seek to develop more income-restricted housing.
The study found that Boston has the highest percentage of income-restricted housing of any major city in the country, officials said.
“This report helps us understand how many income-restricted units there are, where they are, and to whom they are affordable, all important information as we work to increase affordable housing opportunities in our neighborhoods,” Mayor Martin J. Walsh said in a statement.
South End and Lower Roxbury had the highest percentage of income-restricted housing, at 48 percent of the total housing stock, while Roxbury had 45 percent, and Charlestown and Jamaica Plain each had 25 percent.
The review, called Income-Restricted Housing in Boston and conducted by the Department of Neighborhood Development, examined data from the Boston Housing Authority, as well as information on privately owned housing built with city funding or subsidies, or on city-owned land.
The review was in response to Walsh’s “Housing a Changing City: Boston 2030” plan to develop tens of thousands of housing units over the next decade, as the city faces an anticipated population boom.
Walsh recently increased the overall 2030 target from 53,000 new units of housing to 69,000, including 15,820 income-restricted units.
The city defines a unit as being income-restricted when the restrictions are set out in a deed.
The list does not include the more than 16,000 tenant-based housing vouchers available in the city, though residents living in income-restricted housing may also have those vouchers.
According to the report, 27 percent of all rental units in the city are income-restricted, while only 3 percent of all ownership units are restricted. In total, 95 percent of all income-restricted housing are rental units.
Vanessa Calderon-Rosado, CEO of the South End community development corporation Inquilinos Boricuas En Accion, and co-chair of the Mayor’s Housing Task Force, said in a statement that the report reflects the work to preserve income restricted housing in the city, specifically in the South End and Lower Roxbury.
She said that officials “are committed to maintaining and increasing that percentage.”
“The positive effects that living in income-restricted housing has had on generations of Bostonians is real and long-lasting, and must be available in the future,” she said.
Milton J. Valencia can be reached at milton.valencia@globe.com. Follow him on Twitter @miltonvalencia.
