A report on the housing impact of extending the MBTA Green Line into Somerville is warning that rents could skyrocket by as much as 67 percent in some areas and put lower-income residents at risk of being displaced.
Average property values in areas within walking distance of the new T stations also could increase by 16 to 25 percent, and the conversion of more single-, two- and three-family homes into condominiums could affect as many as 475 renter households, with the greatest number of at-risk units in the areas around stations planned for Washington Street and Union and Gilman squares.
The findings were included in a report released Tuesday by the Metropolitan Area Planning Council in partnership with the Somerville Community Corporation and the city of Somerville after two years of work.
Mayor Joseph Curtatone said the city has already been working to address some of the concerns highlighted in the report. One way he said the city is seeking to meet the demand for housing is by setting a goal to create 6,000 new housing units in the city.
“The report reaches some conclusions that we probably could have guessed before, but now we have hard data,” Curtatone said.
The report estimates there will be a demand for at least 6,300 new housing units from 2010 to 2030.
The report, “Dimensions of Displacement: Baseline Data for Managing Neighborhood Change in Somerville’s Green Line Corridor,” was compiled to help focus on ways to offset the displacement of lower- and moderate-income residents that could be caused by creating new transit stops in the city.
Tim Reardon, the assistant director of data services for the Metropolitan Area Planning Council, said some of the report’s predictions about potential rent increases and condominium conversions are based on what occurred after the Red Line stations opened in Porter and Davis squares in the 1980s.
The extension of the Green Line is expected to include the opening of new T stops at Washington Street and Union Square in 2017.
Additional stops in the city are expected to open by 2019 in Gilman Square, at Lowell Street, and in Ball Square. Another stop just over the Somerville line in Medford on College Avenue is also projected to open in 2019.
The report estimates there will be a demand for at least 6,300 new housing units from 2010 to 2030 in Somerville, and said increasing housing production is critical to maintaining the city’s affordability.
At the same time, 272 subsidized rental apartments — which is about 8.4 percent of the city’s affordable-housing stock — could be converted to market-rate housing before 2020, according to the report. Most of those units with expiring affordability restrictions are in the areas where Green Line stations are expected to open, and the report found there will be great pressure to convert the units to market-rate rents.
Demand for housing is expected to cause the sharpest increase to rents in neighborhoods around new T stops at Ball Square, College Avenue, Route 16, Union Square, and Washington Street, where rents are projected to increase by 25 to 67 percent, according to the report.
Reardon said the Green Line extension offers opportunity for sustainable development where more people can live with less reliance on automobiles.
But he said the challenge that has come up in communities across the country is that after transit investments are made in an area, higher-income families that own more automobiles tend to move in and lower-income families tend to move out to more remote locations.
“Who gets pushed out are the poor transit riders,” Reardon said.
Somerville can be different by anticipating the changes that could come with the extension of the Green Line, and working to address concerns before the first mile of track is laid, said Reardon.
Curtatone said that while the Green Line extension brings tremendous opportunity to the city’s residents, it also raises some challenges to the demand for housing and affordable housing.
The mayor said the city has already worked to place some affordable-housing requirements for new developments above state benchmarks, and has worked to add to the city’s affordable-housing trust fund. The city’s passage of the Community Preservation Act will also raise more revenue for affordable housing, he said.
But Curtatone said that even without the Green Line, demand is already increasing housing values in Somerville. He said it’s a problem that the city can’t address without help from surrounding communities and the state.
“It’s a major challenge we’re ready to embrace, and as a community already have in many ways. But we need other communities in the metro region to address that with us,” Curtatone said.
Llocal efforts to address gentrification are underway. The city, Somerville Community Corporation, and Metropolitan Area Planning Council have been holding forums to discuss ways to address the issue. The third in the series of forums, scheduled for March 4, will focus on coming up with strategies for developing an effective housing agenda in Somerville. The forum will be held in the Argenziano School beginning at 6 p.m.