Make sure to have money saved for a rainy day 2X your mortgage and remember house appliances are expensive so to have that already in a storage or if family/friends will give you appliances even better.

Maybe the day the appraiser shows up, the ADU looks and feels like a storage shed (and so on).

I had a SFR with a detached storage/laundry room….it had to pass. 

Each person designated a cupboard area in kitchen,food separate,,, each gets shelf in fridge and tape label stuff,, if they want a extra fridge in their room charge extra for elec .designated parking spots,, and stuff either fits in their room or designated storage spot per person.Weekly chore chart that rotates like trash, vacuuming, bathroom clean up duty,, or hire a maid.I'd cover toilet paper and trash bags.Entry door get's electronic keyless entry and each room also,, easy no keys change code once someone moves..

We have also joint ventured with other investment groups to own a self storage facility in Galveston, TX. 

you mentioned personal storage in your attic for the summer.

My plan is to convert the one car garage into a large studio ADU and add a shed in the yard for storage.

Last year we raised our storage units on average 15% across the board.C.  

It is common to see a MHP that also has SFRs (1-3 buildings), small multi-family (2-3 ,maybe 4 units), RV park and/or Self-Storage all on the same APN.

Do you specifically allow or not allow "outside storage"?