We live in a newly renovated condo, but the windows in the unit were not replaced. The windows are from the 1980"s. We ordered the Indows for a room with North facing windows . . . very cold and drafty! The indows made a huge difference in the temperature in the room. They blocked out the cold and drafts! Before the room was almost not usable without blankets while sitting watching TV. NOW! it is great! Thanks