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The traditional window frame material is wood, because of its availability and ease of milling into the complex shapes required to make windows. Wood is favored in many residential applications because of its appearance and traditional place in house design. From a thermal point of view, wood-framed windows perform well with frame U-factors that are as low as other efficient windows. Wood is not intrinsically the most durable window frame material, because of its susceptibility to rot and warp, but well-built and well-maintained wood windows can have a very long life. Paint protects the exterior surface this needs to be done on a regular basis. Wood windows would be have the highest maintenance of current materials on the market today. UPVC Windows Plastics are relative newcomers as window frame materials in Australia. Upvc, also known as polyvinyl chloride (PVC), is a very versatile plastic with good insulating value. Upvc window frames do not require painting and have good moisture resistance. Because the color goes all the way through, there is no finish coat that can be damaged or deteriorate over time -- the surface is therefore maintenance-free. Some vinyl window manufacturers are now offering surface treatments like laminates (wood veneer, paintable/stainable, maintenance free) and coatings. These products increase color selection and surface appearance options. Recent advances have improved dimensional stability and resistance to degradation from sunlight and temperature extremes.
In terms of thermal performance, UPVC frames are comparable with wood, while there are minor differences, depending on the frame construction. Small hollow chambers within the frame reduces convection exchange, as does adding an insulating material.
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