Is it better to insulate just the basement ceiling, just the walls or both? We have an unfinished basement with garage and we heat it with a pellet stove in winter. The garage is not partitioned off from the rest of the basement. We have no insulation on the walls (cement) and only some of the ceiling is insulated with fiberglass. Some contractors have said it's better to do just the walls, but I assume that's only if there isn't a basement garage involved. Does anyone have any advice?