New Hampshire Subdivision

[Joshua Frahm]

Couple of questions about subdividing a property in NH. Relatively new to REI and have pretty much zero education on property subdividing.

Other information on subdivisions in other states is welcome too.

I have done some preliminary research and was not to successful in finding the exact information I am looking for and hoped some of you could provide some insight.

A duplex on 2 acres with frontage on two roads. I was told to subdivide a parcel with a multifamily house on it, there must be a minimum of 4 acres. Does that sound accurate? 

If this duplex is renovated into a single family home would that be a way to subdivide the property?

Thanks,