The Zoning for Quality and Affordability Proposal currently being reviewed has two changes geared toward tackling a problem housing advocates have been focused on for years. Nearly half of the city’s population is estimated to be single persons yet only 7% of the housing stock is made up of studios and 35% one-bedrooms. “You can’t deny the data,” said Sarah Watson, deputy director of Citizens Housing and Planning Council, “this mismatch causes all sorts of economic distortions.”