I live in one of these in LA. Half the people I know do the same.
bought your house back in 2000? Build a bungalow in your back yard and get someone else to pay your mortgage.
Or, you know, pay $1000/sf for a unibomber shack. For another million dollars you can roll up two more and build your dream home in a neighborhood where the grocery store is named after the local street gang.
Sounds like LA is five years behind Portland zoning wise.
There are some strange constitutionally based tax policies that get in the way of some peoples desires to build ADU's here but there is a fair sized industry devoted to them here.
Tiny Houses are the new fad, trying to solve the housing crises 150 sq ft at a time.