Hosts and home performance experts, Grace and Corbett Lunsford, test and diagnose a recently rehabbed, big, beautiful house in Chicago, IL that now has unexpected comfort and moisture issues, leaving the homeowner not knowing whom to trust. The owner's mother in-law room is never comfortable and moisture beads off the new kitchen windows. Corbett and Grace's testing reveals a surprising answer and puts the concepts of "improved" HVAC on its head.