multi-family rental allocation for personal garage and outside parking space

I own a duplex with a basement that has a garage attached to the basement, as well as an outside parking space. The two units of the duplex and the outside parking space is being rented out, but the basement and indoor garage parking is not being rented out. The garage is attached to the basement, and I'm using both the garage and basement for personal uses. I'm at a loss as how to file the taxes for this scenario. This is what I think is the correct method based on square footage:

  1. Unit 1:  900 sq ft, 3 rooms, 37.5%. (100% rental use).
  2. Unit 2: 900 sq ft, 3 rooms, 37.5%  (100% rental use).
  3. Basement: 450 sq ft, 1 room, 18.8% (100% personal use).
  4. Garage attached to basement: 240 sq ft, 0 rooms(?), 10%, (100% personal use).
  5. Outside Space: 120 sq ft, non-depreciable asset, land only.  (100% rental use).

Should I include the outside parking space square footage in the total square footage to be used in the denominator for allocation purposes?

I'm planning on adding unit 1, unit 2, and outside space as property assets on Sch E, but the outside parking space will not be taking any depreciation due to it being land.

 

I'm not sure about how to deal with the outside parking space. Does this allocation make sense?

How would I allocate the outside space income and expenses?