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The Pros and Cons of Window Films

Solar-controlling window films can block up to 80% of the sun’s heat, boosting a home’s efficiency. Here’s what builders and remodelers need to know. By EVELYN ROYER

With interest in green building and utility rebates on the rise, builders and remodelers are looking at solar-controlling window films as a cost-effective solution for boosting home efficiencies and reducing costs for clients while lifting sales and profits for themselves. Applied to the window, transparent film acts as a solar shield, blocking up to 80% of the sun’s heat, according to the International Window Film Association. “The biggest trend I’ve noticed over the past few years is that people put more and more glass into a home,” says Missouri window film installer Robert Kersten. “Solar control is the payback. [With window films,] in three years you’re going to get your money back and if you buy a good quality product from a reputable dealer, it will last you 20, 25 years. It’s really a bang for the buck.”

Nevertheless, lack of awareness, misperceptions, and the small additional cost are impeding the category’s growth, installers say. Here are some of the product’s pros and cons.


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  • Window film can cut utility costs by 30% to 40%, says California-based consultant Donna Wells, and at $6 to $14 per square foot, it’s much cheaper than replacing windows.
  • Solar films block 99% of UV light that fades furniture, and with better technologies, now do it without looking reflective or dark.
  • Films add security, slowing down a break in and holding shards together if the window shatters.
  • Some state and utility programs offer rebates for window films.
  • While mainly a retrofit product, some films can make a low-cost new window as efficient as a low-E, triple-pane unit, says Wells.


  • Some window manufacturers warn that films will void their window warranty; however, several film manufacturers offer to match it.
  • Certain lites, latches, and frames make installation difficult, and a bad application can leave glass looking bubbly.
  • Most homeowners are skeptical of the benefits, making film a hard sell that requires education.
  • Installers say some film brands are better than others, so buyers should look for NFRC certification.

Still, experts say the future is bright. Products embedded with photovoltaics, even better solar energy-blocking film content, and tinting that users can switch on and off are the future for window films, says Charlie Curcija, a scientist at Lawrence Berkeley National Laboratory. But for installer Kersten, the biggest challenge is right now: “It’s so far out of people’s realm of thinking, the hardest part is to convey what a good product window film really is.”

Evelyn Royer is assistant editor for Building Products. This article originally appeared in Building Products.