If you have bubble wrap lying around the house and you don’t care about the odd look, taping bubble wrap over a window is a very affordable way to insulate it. Another inexpensive option for insulating windows is to add new caulk around the glass. This step quickly cuts down on air drafts for older windows, and a tube of caulk only costs a few dollars. Adding plastic shrink film around the glass is another cost-effective option. You can purchase a kit of plastic film for a few dollars per window.

Most window installation and repair companies can handle putting tint film over your existing windows, but it’s best to hire a company that specializes in window tinting. This decision will result in the best application for the cleanest look, and it usually means you’ll get a better professional opinion about the type of tint and tint level that makes the most sense for your home and personal preferences.

Some frosted glass sprays can handle the outdoors, but most of them aren't built for it. Sprays made for exterior use will say so clearly on the label. Anything marked “interior use only” can't hold up against rain, UV exposure, or changing temperatures without peeling, fading, or yellowing. Outdoor-rated sprays are typically more durable, but even then, proper prep and application matter. Before spraying anything outside, double-check the product instructions. If it doesn’t specifically mention exterior use, skip it. 

Visibility through tinted house windows or privacy film depends on the lighting. During the day, the tint or film typically prevents people from seeing inside. However, at night, if you have lights on inside your home, the interior will be brighter than the outside, which allows people to see in. You can choose from various shades of privacy film, from lighter to darker, to optimize the level of privacy you want.