Scarce affordable housing in the Bronx has prompted an advocacy group to call for change on the state and city level.

According to University Neighborhood Housing Program (UNHP), the combination of a low 2.6 percent apartment vacancy rate and investors buying up property has caused rent prices to spike. "If your building gets sold, there's a good chance that the owner is either going to have to cut back on services because the price they paid for the building is too expensive, or they're going to try as much as they can to raise rents," says Gregory Lobo Jost with UNHP.

UNHP points to a building at 1387 Grand Concourse as a prime example. Many tenants there complain they are continually faced with higher rent prices to pay for upgrades. One tenant says he was forced to rent one of his bedrooms to a stranger to pay the rent.

The housing group wants more state oversight of landlords and for banks to keep track of problem buildings they hold mortgages for.