Is buying a two-family in North Charleston a good way to offset a mortgage?

A two-family in North Charleston can meaningfully offset a mortgage when the second unit's rent realistically covers a significant share of the monthly payment, though that only works if the numbers are run against actual comparable rents rather than assumed. Financing and insurance for a two-family also differ slightly from a single-family loan. Brian Beatty compares recent North Charleston two-family sales against rental data so a buyer can judge the real offset before making an offer.