Adding a unit,,, Residential or Commercial ??

[William S butler]

I have my first property under contract and should be closing within 2 weeks. (thanks to BP and its members!!) Here is the layout,,

Main house has 3 units and there is a stand alone cedar log cabin 920 sq ft. (4 units total - 2 separate dwellings)

There is also a two level garage that is attached to the main house. The garage has been closed off and intended to be turned into another unit at one time, but previous owners had stopped after installing a new furnace and AC for unknown reasons.

My question is,,, Can I remodel this garage into a "5th" unit and still be zoned residential being they are separate buildings and not 5 units in one building??

They are all on the same plot of land.

Thanks to ALL BP members for help in educating me in this space !!

TIA for your feedback.

Scott