California Energy Commission approves new Window Film Savings Calculator

April 29, 2016

This March, the California Energy Commission approved a tool that is helping local schools pay for energy-saving window films.

The all-new Window Film Savings Calculator makes it easier for school districts to ensure their installation projects qualify for funding under the state's Proposition 39 grants, which can cover up to 100 percent of energy efficient upgrades for school buildings.

Designed by the International Window Film Association, the tool gives local education agencies a quicker, more cost-effective way to demonstrate their projects' potential savings to the CEC. According to a release from the IWFA, the calculator has the potential to replace burdensome full-building energy simulations, which were previously required to determine the effect window films would have on a building's performance.

"Before this approval, there were existing, simple calculators already approved and in use for many of the other such upgrades, but none for window film installation," said Darrell Smith, executive director of the IWFA in the release. "This year-long effort to develop and make available a tool which met the specifications of the CEC for the sole purpose of analyzing a window film installation as a standalone upgrade measure under Proposition 39 program guidelines will prove valuable to California schools."

"Installing reflective window films is a convenient alternative to replacing windows outright."

Saving energy with high reflectivity window films
Installing reflective window films can be a convenient alternative to replacing windows outright. According to, the films use a nearly invisible metallic coating to filter out infrared heat as it tries to enter a building, keeping buildings cool during summer months while still allowing sunlight to come through.

This means that even after their windows are treated with high-reflectivity films, schools will still be able to enjoy the productivity boost and energy savings of natural light. However, the film's heat-blocking technology is equally as effective in winter, when buildings might enjoy the warmth of the sun. For this reason, suggests window films are best used "in climates with long cooling seasons," making them ideal for use in California.