Windows are usually the weakest point in a home's thermal envelope. Film applied to existing glazing reduces the solar heat coming in through the sun-facing elevations, which eases the load on cooling equipment during warm months. It also cuts glare and reduces ultraviolet light, the main driver of fading in floors, rugs and furniture. For many Beverly Hills homeowners, adding film to existing windows is a far smaller job than replacing glazing units, and it can be done room by room where the problem is worst. Performance depends on the film, the shade and the glass it goes on, so ask an installer what to expect from the specific combination in your home.