Window City supports continual education and development of sustainable, energy-efficient fenestration materials. The relevant properties of coating (low-E), glazing, visible light transmittance (VLT), and solar heat gain coefficient (SHGC) are important considerations when specifying windows and doors. For every window and door Window City supplies, the company takes the energy efficiency and lifecycle of the product’s material into consideration. The more energy-efficient the material is, the less energy will be needed to heat and cool customer’s buildings. The greater the longevity of the product installed, the fewer products need to be manufactured. This in turn translates to less resources used and reduced impact on the environment.