Splitting a lot in to 2 parcels?

[Derrick Holden]

I just got an offer accepted with a property on a .28 acre lot with a large Victorian split in to 4 units and a in law unit with a separate driveway and porch leading outside essentially its own house. 

My question is, how do I find out if a lot is splittable? Which would really change the potential of my deal.