A major obstacle is a costly requirement to install fire sprinklers in all units when a fourth unit is added. Fire sprinklers save lives and property. Every new unit adds a stove and furnace, both fire sources. The requirement is reasonable, but the cost (at least $30,000 for a three-unit building) would stop owners from adding a unit or two.
This issue needs to be confronted head-on. Requirements could be relaxed. Cheaper options might be found. Most effective might be tax credits to bring costs down – far more cost-efficient with tax dollars than building “affordable housing” from scratch. Fire safety people would be very happy to see fire sprinklers encouraged broadly.
Another possible issue is accessibility for the handicapped. Because of these issues, Massachusetts and other states, and even the U.S. Department of Housing and Urban Development (HUD), may need to convene a Task Force on Rental Housing Policy to sort out the various issues.