Our house was built in 1939, but we recently remodeled: Attic almost completely full of blown in insulation, spray foam inside all walls, siding bonded to 1" insulation. We have not replaced the windows yet, so we have a very well insulated house with 23 rectangular holes. Gas stove (wouldnt have it any other way), gas furnace, gas fire place, gas hot water heater, combined bills are still less than $200. We put A LOT of insulation in the house, but as stated earlier, Im worse than Anne Frank on keeping lights and other stuff turned off.