It sounds great and is a great idea, but the reality is that ADUs, tiny homes, and multi-family units will not be any less to rent than current apartments and smaller homes. For example: If you build an ADU, you will have to buy all the permits needed from the city of Olympia. Most likely you will have to borrow the money to build the ADU. Then when you are all done, the Thurston County Assessor is going to revalue your house and property. So I don’t see how anyone is going to have a lower rent.
What if the city of Olympia charged a lower permit fee or spread the cost over a 10-year period. And maybe the Thurston County Treasurer could not tax the new structure for the first 10 years. Then you might have a lower rent base.