Thanks, Reba, for the expanded explanation of lowcountry.
Rebel, congrats to you! Hmmm, do you know what material the actual roof is made of? I would imagine it is cast concrete and then the dirt placed on top. You mentioned windows which is good and critical. When you go thru the house, get an over-all feeling for it. Some earth-bermed homes, depending on design CAN be depressing, give you that closed in feeling. It should be airy and bright (bright colored paints, lighting, etc). Also critical is the eaves in front. If it was done right 20 years ago, a measurement should have been taken then to determine how far out the eaves should be for your immediate area. The result of this measurement/engineering to determine how far the eaves jut out will be based on the sun. You want the eaves to block out the high summer sun but not so far out that the eaves block out the low winter sun when you want heat gain, yadda, yadda, yadda. Some of these homes can be really air-tight but the house needs to re-fresh the air several times a day for safety. If the balance was struck right 20 years ago, you might be able to toast some bread and the house is warm, lol! You should have really low utility bills. Maybe ask to see the history of the utility bills for a year or two.
I better stop here, lol. U just do/feel/determine what is right for you and your family by touring the place and ask a few critical questions. Best regards in this new venture!!