Window Film Blog
Photo of person installing window film on interior of window

FAQ: Does window film go on inside or outside?

Does window film go on the inside or outside of a window? This is a question we get asked a lot!

In general, nearly all window films for residential applications are made to be installed on the inside of windows. There are window films that can be applied to the outside of a window, but they are generally not available online or direct to consumers and they serve a specific purpose.

Woman installing window film herself on her home double hung window

Why is window film installed on the inside of the window?

Installing window film on the inside of the window is generally easier and more practical for a few reasons:

Protection from the elements:

When window film is applied to the inside, it is better protected from external factors such as rain, snow, dirt, and debris. This helps maintain the film’s appearance, performance, and durability.

Accessibility:

It is often easier to access the inside of windows, particularly in multi-story buildings or areas with limited outdoor access. Working indoors also provides a more controlled environment, which can be beneficial when handling the film.

Adhesion and cleanliness:

Applying film to the inside of the window allows for a cleaner surface, which improves adhesion. Exterior surfaces can accumulate dirt, dust, and other contaminants that can affect the film’s ability to adhere properly.

Safety:

Installing window film on the inside is generally safer, as it reduces the risk of falls or accidents associated with working at heights or in difficult outdoor conditions.

UV protection:

The UV-blocking agent in window film is most often found in its adhesive. It not only protects you from harmful UV rays, but also the film. For an interior film, the UV protection is the first thing the sun hits before it hits the film. Window films applied to the inside effectively block harmful UV rays, reducing fading and damage to interior furnishings, flooring, and artwork.

Aesthetics:

Applying the film on the inside of the window maintains a more consistent and cleaner appearance from the exterior view. Part of this is because it is easier to keep the interior of the windows (and therefore film) clean.

While there are some films designed for exterior application, the benefits of installing window film on the inside generally make it the preferred choice for most situations.

When would you use window film on the outside of the window?

There are several types of window films specifically designed for exterior application. These films are engineered to withstand outdoor conditions and are often more durable and weather-resistant than interior films and are also more expensive.

Most film types (privacy, solar control, etc) are available to professionals in exterior options for instances where it is impractical or impossible to apply the film on the interior of the window. These situations might include:

  • Disturbing tenants in an office or multi-family building
  • Inaccessibility to an exterior window in a commercial building because of the ductwork or other obstructions
  • Height of skylights or glass roofs

Specialty Exterior Films

Then there are some types of window film that are only meant to be applied to the exterior of the glass. These include:

Anti-graffiti films:

Picture of graffiti on a window for a blog post about window film

These films provide a protective barrier against graffiti, vandalism, and other forms of damage. They can be easily removed and replaced if defaced, saving time and money on cleaning, or replacing the window itself.

Turf or siding protection films:

Picture of melted vinyl siding on the side of a house
Source: Green Building Advisor

These are not transparent window films as we typically think of them, but perforated PVC screens that you apply to the exterior of the window to reduce the reflectivity of your glass back on to your artificial turf, outside furniture, or neighbor’s vinyl siding. Turf Guard and Turf Shield are examples of this type of film.

Conclusion

Most homeowners who are looking for solar control, energy efficiency or privacy will choose a film that is applied to the inside of the window. Concord Window Film has easy to follow step-by-step instructions and instructional videos to get you installing window film like a pro in no time. Shop our DIY professional-grade window films now.

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