@ThomasM125 That all makes sense to me. The remnant question then is: Is the Rental "C" considered "personal use" if it is a room in the attic of your home (primary residence) that stays UNUSED/EMPTY - unless when rented out to a non-family member? Or is it correct and safe to classify this just like every other rental we have - except that we pro-rate all relevant entire-house costs and a share of depreciation (based on sqft share)?
I read an article in the CPA Journal (link: https://www.cpajournal.com/2019/11/11/tax-treatment-of-home-sharing-activities/ - see "special situation in the middle) that suggested to me that renting a room in your residence is a "special situation" that ALWAYS has to be treated similar to a home office: No losses are allowed to be applied anywhere than against the rental "C" itself. Not against other passive income (ie. A and B) nor against anything else, EVEN tough these C rental incomes are considered "non-passive" income. But maybe I am gettig all of that completly wrong, like others on TT discussion strings I have seen on the subject.
