My house, a small one-story bungalow built in 1917, has 8 double hung windows and 5 smaller windows in a sun room. For 12 years, I used plastic shrink-wrap insulation. This summer I spoke with Indow Windows and decided to take the plunge. Seven weeks later, my inserts are installed. I could not be more pleased. They look terrific, for one thing. Customer service was stellar (and astoundingly patient). Installation was straightforward, even if nothing in this little house is precisely square, and fairly easy. It took a bit longer than suggested, but not that much. No freezing overnight temperatures quite yet but the first night with the inserts the temperature inside was 2 degrees warmer than the previous night without them. This speaks volumes for me. I can't wait to see the difference when I finally crank up the furnace on November 1. The investment was a sizable one for me but an excellent one worth every penny. Thank you, Indow !