A rental building turned megamansion hit the market in November for $16 million, making it the priciest single-family home listed in Brooklyn last month. The seven-bedroom home at 146 Willow Street in Brooklyn Heights underwent a two-year gut renovation to convert it from a rental building. The six-story home spans 8,850 square feet. Meanwhile, November’s most expensive listing in Queens was a duplex penthouse at Casa Vizcaya, a five-story boutique condominium building in Long Island City.