Here at the Window Source of Houston we only offer the highest quality energy-efficient replacement windows on the market. What distinguishes us from other window companies is that all of our windows are backed by a lifetime warranty. Because of this warranty, you can rest assured that you will have nothing to worry about once your windows have been replaced. The Window Source of Houston warrants to the original purchaser as well as the next subsequent homeowner on all (when applicable) windows and patio doors.