The market is ruthless , supply can't keep up, and over half of residents pay more than 30% of their income in rent — the threshold economists say is unaffordable. Schwartz, a property developer and lifelong Brooklynite, hopes a conversion of the historic Stewart Hotel can be part of the solution . By 2029, the midtown Manhattan building's 611 vacant rooms are scheduled to become over 550 affordable apartments for low-income and formerly-homeless New Yorkers. It's part of New York City's