WPC or PVC door frame provides better insulation and therefore better energy efficiency than a traditional timber door. When used as a door frame, WPC and PVC are actually three times more energy efficient than its aluminium counterpart. It is also virtually maintenance free, never requiring stripping or repainting. Just wipe the surface clean occasionally and it is as good as new. While a timber door frame will warp, shrink and expand over time, a WPC and PVC door frame remains perfectly stable because it is 100% waterproof.