Last winter I decided to replace my two 12 foot single pane patio doors with Affordable windows. Jeff suggested using three 4 ft panels instead of four 3 ft panels. Not only was it less expensive but it vastly improved the view. I was going to go with dual pane but they convinced me to go with argon gas and I'm so happy with it! Not only did it lower my utility bills $50/month this summer but the room is more evenly cooled and comfortable. The installers knew exactly what they were doing even with these large doors. I wish I'd gone with Affordable Windows for my other windows. I'm in the process of a large addition and remodeling project and I'll definitely be calling Affordable Windows for all the doors and windows.