It would be hard to argue with the fact that San Diego has an affordable housing issue… average rents have increased by 20 percent in the past three years and there are fewer vacancies now than ever. Last month the San Diego City Council took a step aimed to encourage the construction of more homes. They’re officially called companion units, but are also known as granny flats–small apartments built in the backyards of existing homes. KPBS reporter Claire Trageser has details.