My apologies, but I have a hard time comprehending what is so difficult to understand about this. I can't make it any more simplistic than it already is.
One you convert the property **OR*** the space in your house to rental use, it is *NO LONGER* personal use. Therefore it was no longer for *YOUR* *PERSONAL* *USE*. You did not live in it, (or use that space in your home that you have identified as being *EXCLUSIVELY* rental space) for your *PERSONAL* purposes. Therefore *YOU* did not live in the property, or utilize the space for *ONE* *SINGLE* *DAY* ************AFTER*********** You converted it to rental property. So your days of personal use *MUST* be ZERO.
Now if you did *in fact* live in the property or use the space for your personal use ****AFTER*** you converted it to rental, then *ALL* of your expenses and depreciation will be aportioned accordingly and you will *NOT* be allowed to deduct *ANY* expenses (including depreciation) for the period of time it was personal use ******AFTER***** you converted the property to rental.
