Through the end of 2013 you can defray a bit of the cost with the federal tax credit for installing energy-efficient windows in your home. The credit is worth 10% of the cost, up to $200 (excluding installation) and applies to replacement windows or new ones installed in an addition.e generally charges $40 to $200 per window to install them. Windows painted shut long ago will open and you'll preserve the architectural or historical character of your home -- which some neighborhoods may require anyway.