House Hacking Taxes - Duplex 75% rented

[Zach Adams]

Hi All, I have a house hack which is a duplex. I rent out the lower unit and for the upper unit, I rent 1 of 2 bedrooms. I was told that I could only depreciate 8.6% (square footage percent of the upper unit) and only deduct repairs done to the rented room alone. Is this correct? I was under the understanding that I could do a room ratio and deduct 50% of the upper unit expenses due to all other areas being equally shared. If I am correct, does anyone know where this is in the IRS code? Thanks.