Southern California was built on the sale of sunlit homes in affordable real estate developments. But the many building booms of the past century haven't been enough. In just the past 15 years, Los Angeles has added 230,000 new residents, but only 40,000 new homes. The median cost of a home in L.A. has doubled in the last five years. Rent climbs ever upward. So, who is L.A. for?