Renting out SFR as an over/under Duplex

[Joshua Seward]

I just submitted an offer on a property in Nampa, ID and am looking for some advice. The property is a 4 bed/ 2 bath with a basement (2 bed/1 bath with kitchen in each, each have separate entrance). It is zoned for multi family, but right now it is a SFR. Everything is on one meter. Ideally I want to be there for a year or two then move out and continue renting each dwelling unit.

I am wondering if there is anything legally that would prevent me from doing this without going through the process of making it a legal duplex?

Any advise would be greatly appreciated as this will be our first purchase. Thanks in advance.