Home Value when converting primary to rental

[Mike Arias]

Hello, my goal is to convert my primary SFH to a rental. From what I read, depreciation is calculated on the purchase price of the investment property. In my situation, I purchased my primary over 22 years ago and I assume I don't use that "purchase price". I assume I use the current value of the property (I know its the value of the house only; excluding land) when I "convert". So my questions are:

- Do I need to get an appraisal to determine the value of the property so I know what to use to calculate depreciation?

- When exactly does my primary become a rental property?  When I move out? Or when the house is rented?

I know this is common but I never have heard any podcasts, blogs, or videos talk about this.  I have read Amanda Han's tax book (first book) and started on the Advanced Tax Strategies and don't really see this mentioned. 

I assume there maybe some nuances when one turns their primary home into a rental (not house hack but full rental so my wife and I will move out).  Anything else I shoudl be aware of?  Thanks in advance.