He believes that urban density––tall apartment buildings––can have an isolating effect. He says he doesn't talk all that much with the neighbors in his apartment complex. But other Pac Heights residents––even some in the tallest buildings––have had a different experience. Rina and David Collfield moved to San Francisco fifteen years ago from Colorado. Now they're building managers and fire safety directors for their building on the corner of Washington and Laguna. They feel that their building feels more like a small town; everyone knows each other but doesn't get overly involved in each other’s lives.