1 This are called new construction windows, and can cost as much as 50-100 percent more than replacement windows, or $5,000-$40,000 for completely rebuilding all the windows in a home.dditional costs: 1  A window installer should remove the existing windows, install the new ones, cleanup and dispose of the old windows, and wash the new windows. 2  Estimates are usually based on united inches, which is equal to the sum of the length and width of each window; a 40x55-inch window is 95 united inches.