The Pelli-Clarke-Pelli building that someday may be the fourth tallest in San Francisco—and is the last vacant property around the Transbay Transit Center set for development—inched toward the finish line Thursday as the SF Planning Commission approved the project. Potential hurdles going into the long-awaited hearing this week included worries that the nearly 750-foot tall tower at 542-550 Howard Street will cast shadows over parks in Chinatown. The staff report prepared for the hearing cited no fewer than eight groups who objected to the building’s shadow profile, most notably the Committee for Better Parks and Recreation In Chinatown (CBP&RC, part of the Chinatown Community Development Center). In San Francisco, Prop K, which passed in 1984, bars new high-rise developments that will have any “adverse impact” on parks “because of the shading or shadowing that it will cause, unless it is determined that the impact would be insignificant.” SF Recreation and Parks did determine that the Howard Street development’s effect on the park would not be particularly notable, but neighbors could still have challenged it in order to hold up construction. But in a surprise move, a CBP&a...