A digital “Twitter wall” flashes trending neighborhood topics inside the lobby of a new high-rise in the theater district. A freshly built luxury building across town lures affluent young professionals with sunset yoga and hip-hop parties on the pool deck. Downtown, one of San Francisco’s best known restaurateurs, Michael Mina, will craft a new entree every month for residents of a sleek condo tower. And homeowners at a glass skyscraper set to open in 2018 will be able to sip cocktails in private “sky cabanas” overlooking a rooftop pool. They may need to look out the cabanas’ glass walls to remember what city they’re...