My husband and I live in a 100 year old Chicago bungalow with a finished attic. We have no issues with the heating or cooling on the main floor, but the second floor (attic) is always either too hot or too cold. We have discussed putting in some sort of insulation but are unsure of where it will be most helpful, exactly which type to use, and/or if this will solve our problem. We have also considered replacing the older windows in one of the bedrooms (the other windows are new) or putting in a mini split ductless air conditioner unit. Any advice would be appreciated. Thank you!