Pier 70 is undoubtedly one of the more complicated development projects proposed for San Francisco at the moment. There are two developers working on two separate parts of the pier. Orton Development is gearing up for a September 1 start date on the $100 million rehabilitation of six old industrial and office buildings along 20th Street, south of Mission Bay. Come 2016, those structures will reopen as office, light industrial, and flex space. Meanwhile, Forest City is getting ready for a November vote on Proposition F, in which voters will decide whether current 40-foot height limits can be raised to 90 feet for a 28-acre portion of the site.