Everything You Need To Know About Aluminum foil on windows

Last Updated on May 4, 2021 by Kimberly Crawford

Have you walked past houses with windows covered in aluminum foil? If you find it weird, then you do not know that it is there for all the right reasons. There are various reasons why homeowners wrap their windows with tin foil but the most immanent would be, it is helpful in preventing glaring and in keeping your home well-insulated

But more than these, there are still a lot to know about aluminum foil on windows and if you are curious about how this works, this post has all the answers to your questions so read on. 

Does aluminum foil on windows keep heat out?

Yes. In baking, aluminum foil keeps the food unburnt from direct heat exposure in the oven. Following the same logic, aluminum foil on the window keeps the heat out because, well, it is heat resistant. As such, wrapping your windows with aluminum foil generally maintains the low temperature inside your home. 

Does aluminum foil on windows keep the cold out? 

Not entirely. To trap cold air and keep it from entering the home through the window, you should add another insulating agent which can come in the form of a bubble wrap. You can easily remove the bubble wrap and change the foil after winter. 

Benefits of aluminum foil on windows

aluminum foils

Aside from keeping the heat out, here are other benefits of wrapping your window with aluminum foil. 


Even with blackout curtains installed, total privacy is not usually totally achieved. To add reinforcement, you can wrap your windows with aluminum foil. With its level of opaqueness, nothing can seep through it, not even heat. 

Cheap blackout curtain

Instead of fabric curtain that you need to dry-clean every now and then, you can go for aluminum foil. It does not give the trendiest look but if the purpose is just for blacking out, you can opt for cheap aluminum foils. 

Stops glaring

Windows with direct exposure to sunlight prone to glaring. When this happens, you cannot watch your TV clearly or use the mirror. Aluminum foil on the window prevents light reflections in the room. 


Homes with larger windows can benefit a lot with aluminum foils. It helps insulate the home during hotter summers and colder winters. And because it is a flexible material, aluminum foil can easily take on the shape of whatever size of window that you have. 

The benefits that you get from aluminum foil on windows are primary zeroed-in to insulation functions. They may sound very basic, but they offer a lot of benefits to your home without even batting at more than $100. 

What are the drawbacks of aluminum foil on windows?

aluminum foils on windows

Of course, aluminum foil has its own drawbacks especially when wrapped around windows.

  • It can look messy: If you have wrapped the windows hastily, crumpling the foil in between, of course it would look messy. It also does not come with decorative designs so you cannot amend the aesthetic part. The good thing is that not all windows in your home should be covered. Just choose the ones that are most heated by the sunlight. 
  • Foil on windows invite suspicion: Speaking of ‘looking weird’, windows wrapped in aluminum foil can look suspicious or can give the idea that you are doing something illegal. The prime intervention here is to put more accuracy and artistic touch to how you install the foil on your windows. 

Aluminum foil alternatives

Because it is not always the most aesthetic choice, you can always check the following to use as aluminum foil alternatives: 

  • Blackout curtains: These choices are always the first choices. Aside from blocking out light, it also insulates the room by acting as a thermal barrier. 
  • Blackout shades: If you want a more convenient choice, go for smart blackout shades. You can just use a remote or voice command to open and close the blackout shades. 
  • Window film: This is the best choice to limit the amount of sunlight seeping through your window. You can reinforce this better by adding a UV barrier or a light rejection film. 
  • Awnings and eaves: These added structures are the classic interventions to reduce the amount of sunlight coming through the windows. And if you do not need a total window block out, you can install awnings for decorative use while limiting heat.  
  • Heat resistant films: If you do not want a total window block out but want to significantly reduce the heat coming into the room through the window, you can just spread a heat resistant film. 

Related: Do Thermal Curtains Work In Summer? [Pros and Cons]

How to put aluminum foil on windows

Now that you have understood the logic of putting aluminum foil on your window, here are the steps that you should be familiar with so that you can try it on your own: 

  1. Get a tape measure. Do this to get the total area that the aluminum foil will cover once you spread it. 
  2. As per rule of thumb, always add extra 3-inches on each side of the window so that you get spare material for better fitting. 
  3. While this is optional, you can also add bubble wrap underneath the foil to generate better insulating capacity and a thicker barrier for sun glares. 
  4. Now, cut the foil in accordance with the measurement of your window plus the 3-inches addition per side. 
  5. Spread the aluminum sheet in the window frame. Make sure that you flatten the surface as the aluminum foil is spread. 
  6. To secure the aluminum foil in place, use transparent adhesives. Make sure that the whole glass area of the window is all covered with foil. 

Where should the shiny part of the aluminum foil face when wrapped on windows?

When you are installing aluminum foil on windows, the shiny part should always face outwards. This part is the reflective part of the foil which is functional in deflecting sunlight before it could seep through the window. 

Is it illegal to put aluminum foil on windows? 

Fortunately, there are no existing mandates about totally blocking out windows. In terms of the materials that can be used for a window block out, aluminum foil is not listed on the prohibited materials. As a matter of fact, for people living in apartment compounds, privacy is highly encouraged. 

Can aluminum foil damage windows?

Yes, but on bare minimum. The only damage an aluminum foil can do to damage windows would be small scratches that a glass buffing material can always fix. Other than this, aluminum foil on windows is generally safe to use for wrapping windows. 

What type of aluminum foil is used for windows? 

You might have been visualizing the kitchen aluminum foil all this time but really, we are talking about radiant foil barriers. Kitchen foil is not just that ideal for windows because they are not that durable compared to foil barriers. 

If you are wondering about the best radiant foil barriers out there, you could check Enerflex Radiant Barrier, Energy Improvements, or Attic Foil. These foils come in at least 48-inches wide (which is a good fit for the standard window width of 36-inches) and comes 125ft or 250ft rolls. 

Is it safe to put aluminum foil on windows?

Contrary to popular belief, aluminum is safe for windows. There are three common misnomers about aluminum foil. One misconception is that it melts when it really does not. It is used in baking and it comes in one piece after you take the food out, so go figure. 

The second misconception is that aluminum foil is a fire hazard. You must know that aluminum foil has a high resistance to heat. As a matter of fact, its listed melting point is 1220F which is way higher than the registered highest temperature ever recorded for the worst summer in history. 

The third misnomer is about it emitting toxic materials. Aluminum is toxin-free. It also does not emit toxic materials and would not rot. So, if it safe to use for food, we do not see how it should not be safe on windows. 

Do aluminum foils on the window work? 

With all the things that we have covered here, yes, aluminum foils on windows work. Scientifically, the capacity of aluminum foils to keep heat out by absorbing it is called emissivity. This is also the reason why the shiny side is put up to absorb direct sunlight. The greater reflecting ability of the shiny side gives it higher emissivity. 

How can aluminum foil residues be taken off when you change them? 

You can try removing the foil residues by using one of these substances: 

  • Window cleaner
  • Washing soda
  • Vinegar
  • Rubbing alcohol


Aluminum foil on the window is probably the cheapest reinforcement that you can install to do more than what curtains do. Contrary to common beliefs, aluminum foil is generally a safe material to use for your windows.

It is also a good insulator for the home, giving you more warmth during the winter and less heat during the summer. With proper installation and accurate measurements, you can gain all the good things that aluminum foil can offer.