Years ago mom had good windows put in. So after she passed we had some work done on the house before we moved in. Had insulation blown in attic and new doors and storm doors put in. It is an older brick house from 1955 that my grandpa had built. It is solid brick on outside. Red blocks inside that with sim cement coating over that from what we could tell. No way ton sulfate walls without building new walls inside. Yes will be getting energy efficient air conditioner.