Pre-war housing stock, and the diagnosis that starts on the phone
Much of Brooklyn's residential stock predates the systems inside it. Park Slope brownstones and Bay Ridge rowhouses are running steam risers, converted one-pipe systems, knob-and-tube remnants, cast-iron drain stacks, and boilers that have been retrofitted twice. Bensonhurst and Canarsie add decades of owner-built extensions and finished basements where the mechanicals were never meant to live.
That history changes what you need to know before dispatch. Whether the building is one, two, or three families decides who is authorized to approve work. Whether the basement is finished decides whether you are carrying a snake or a camera. Whether the heat is steam or hydronic decides which technician you send. A voicemail that says 'no heat in Greenpoint' tells you none of it.