Multi family zoning

[Brad Morsberger]

I have recently been looking at a property for sale where I live and it has me quite confused.  It is a 4 bedroom 3 bath single family home converted into 3 apartments.  There is a 2 bedroom and two 1 bedrooms.  It is only zoned for 2 apartments.  My plan is to move into the extra apartment as a primary residence and rent the other two rooms.

The house was converted sometime after 2006 and the owner converted the apartments by himself and I am not quit sure that they are legal apartments, although all 3 are separately metered.  Is there a way to rezone a property that you do not own but have a contract to purchase? Maybe some sort of contingency?