4 unit or add 5th unit?

[Michael Cross]

I am under contract for a 4 unit property with a lot of poorly allocated space from additions over the last century.

Utilities are separated per unit already.

One first floor unit has enough space for to be a 3bed/2bath or convert to 2 - 1 bedroom units

4 unit ARV is $240k, $2800 gross rents

5 unit would be $3400 gross rents

What other issues other than being forced to use commercial financing should I consider before making the conversion?

Zoning would permit it, large lot provides plenty of space for parking or additional unit construction

Thanks in advance