The Show Stopper pisze:Yes it's true that PVC is cheaper, but metal is just as easy to mold as pisltacs. The true value of PVC used in window frames is it's higher R value than metal, which means that the PVC is a better value than metal in terms of insulation. Because the PVC has a between R value means that your house will be cooler in the summer and warmer in the winter, because less heat will be lost to the surroundings. The framing of a window is the least insulated part of a window. In many cases, window vendors try to pass off excellent R values for windows, but that value is only of the glass used and the air between the glass panels, not including the the frame.