ADUs are becoming more and more popular. There are so many possibilities: a rental unit, mother-in-law apartment, studio/office and on and on. I am personally a big fan; it might be because I always wanted a playhouse as a child! The city of Portland has an informative website which gives you an outline of the process and rules. I recently took a class from an architect that has done a number of them in Portland. They also have great information plus photos and layouts of ADU projects they have done around town.
So, if you decide to do or have done an ADU please, please let me know… I would love to stop by and see it!!