On Christmas day 2017, KPCC featured a radio bit and article discussing the growing popularity of ADUs (a.k.a. Granny Flats) in Los Angeles starting in 2017.

Quote from the article "the application rate for accessory dwelling units in Los Angeles far outpaces any other major California city. L.A.'s planning office had received nearly 2,000 applications by November, according to the Terner Center for Housing and Innovation at UC Berkeley. In contrast, the city approved permits for just 80 units in 2016 and 90 units in 2015." - Josie Huang

Here is the article and audio in case you missed it.