I came down to the same reasoning as @Jesse Hyder with cashflow and @Kyle Z. with vacancies (or reducing risk exposure).

You don't have to worry about exterior maintenance, mowing, exterior insurance, roofs, and possibly utilities.

If you can utilize one or all of these comfortably it will help a lot.2.

Also, at least here, it would depend on how they were built-for separate fee simple units, they would have to have separate utilities, not crossing the common property line, otherwise they would have to be condominium ownership if divided.

Are there any utilities that you have to pay?

Hope that's good advice for you.What I highly recommend is try to network with other investors in your area and pool your properties together in an effort to reduce your maintenance expenses.

A couple thingsNot sure if NC has this, but in MI the utility companies have landlord programs.

You can have multiple gas meters installed so that each tenant pays their own utility bills.

Consider utilizing a corporation and a 401k for matching contributions to decrease some of that taxable income.

I may even cut back to 1 or 2 zip codes to further reduce my risk but my fear is that I will pigeon hole myself into a certain area and slow down my progress.