It doesn't have to look like Hong Kong. Paris isn't as dense as Manhattan, but it's something like 2/3rds as dense despite relatively few tall buildings. SF cou

It doesn't have to look like Hong Kong. Paris isn't as dense as Manhattan, but it's something like 2/3rds as dense despite relatively few tall buildings. SF could allow mid-rise European style development and grow quite a bit denser. If SF had Parisian density, it could fit something like 2.5 million people. Other places in the bay could also not make suburban living mandatory. Housing affordability and environmental problems are a national issue. IMO the best solution is a Federal law that makes it impossible for cities to mandate suburban living. That avoids the problem where one city liberalizes land use and then sees huge development while others keep their doors closed.