We consider buying an apartment, which has previously been used as a shop. Our only concern is that it has large windows (2,5 meters x 2,5 meters), which would function like an invitation to burglars. I am thinking that we could buy bullet-proof glass to make it much more difficult for burglars, though, I have never heard about anyone doing this, and I have not been able to find any shops selling such glass. Therefore, I was wondering whether bullet-proof glass of this size would really help against burglars, and what we would be talking about with regards to price compared to ordinary glass (are we talking about hundreds of thousands of dollars per window or just a few thousands)?

EDIT: I am not so worried about economic loss, this is more an issue of whether I would actually get out of bed if I heard strange noises in the apartment at night.

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    Bullet proof acrylic sheets
    – Tester101
    Commented Sep 21, 2011 at 15:17
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    Lexan (Polycarbonate) at 1" thick will stop most handgun bullets, but rifle rounds may not be stopped.
    – Tester101
    Commented Sep 21, 2011 at 15:24
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    Related: diy.stackexchange.com/questions/3276/… Commented Sep 21, 2011 at 18:42
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    I'd be more paranoid about people looking in, and needing to have the curtains drawn at all times ... or drunk people thinking it looks like a shop at night, and trying to come in. (I've heard about this happening w/ converted buildings)
    – Joe
    Commented Sep 22, 2011 at 4:55
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    All of that is great, but don't forget about the fire department. If there's a fire and it takes them 15 minutes to break the windows, you will be toast.
    – user55360
    Commented Jun 18, 2016 at 2:37

11 Answers 11


There is a product called Window Security Film which is a thin (a couple mm) film that adheres to the window and makes it exceptionally difficult for someone to break. Many lock smiths/security companies can install it. Here's a video of it in action: http://www.youtube.com/watch?v=vYdVK3BqPfk

One of the biggest "problems" with it however is that because it's invisible, people will still try to break the glass. For this reason, often it is installed along with window bars since this provides a visual deterent, but they are pretty ugly for residential installs.

  • I was worried about the price of this, but is seems to be very low compared to bullet proof glass. Thanks for the tip!
    – David
    Commented Nov 29, 2011 at 22:16
  • they used it all the time on 'It Takes a Thief'
    – warren
    Commented Nov 26, 2012 at 19:08
  • Window film is a good answer. Lexan glazing (NOT a ballistic version, just shatter-resistant plastic!) is another good answer, and may look nicer, but is more expensive and may be somewhat more scratch-prone.
    – keshlam
    Commented Oct 30, 2014 at 22:49
  • Many lock smiths/security companies can install it. what about DIY? Or would that likely be a bad idea? Commented Mar 30, 2017 at 15:53
  • @MattBurland no idea about your capabilities. It's not rocket science to install so I don't see why not...
    – Steven
    Commented Mar 30, 2017 at 18:09

Another angle - if it is the size of windows you are worried about, have you thought about altering the frontage to have smaller windows? It would then look less like a shop, and it would be easier to get laminated glass for the windows.

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    Don't use toughened glass - it breaks into nice safe bits, use laminated glass instead, however +1 for putting in smaller windows.
    – Walker
    Commented Nov 30, 2011 at 12:54
  • Toughened glass would make breaking in easier really.
    – DMoore
    Commented Mar 21, 2019 at 19:56
  • Thanks to @DMoore and Walker - I have removed the word toughened. Laminated is what you want :-)
    – Rory Alsop
    Commented Mar 22, 2019 at 9:08

Put in a simple alarm system with glass break sensors. Dedicate it to the windows if necessary and leave it on all the time. If anyone ever tries to break a window the alarm will sound. You would not even need to have it monitored if all you want is peace of mind while sleeping.

  • That does not stop someone breaking the glass, it is a real pain to get windows fixed even if the person runs away after the alarm goes off. If you don't get the windows fixed without hours, they can just keep setting the alarm off until it get's ignored, then go in!
    – Walker
    Commented Nov 30, 2011 at 12:56
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    In his edit David says he wants to sleep well at night. An alarm would do this for him. That is why I gave the answer, and I guess that is why it is being up voted. Commented Oct 23, 2012 at 1:01

I'm pretty sure bullet proof glass is not a viable option. A quick Google search came up with a 40" wide window for over $3k. I couldn't find anything nearly the size you mentioned, and I'm guessing the cost for increasing scale is not linear - you're talking at least tens of thousands of dollars here. My guess is that the glass would end up costing just about as much as the apartment, if not more. Plus, bullet proof glass isn't completely shatter-proof. An attempt to break it could leave it cracked, and there goes the most expensive thing in your apartment.

Plus you've got to consider if the window is even your most vulnerable point of entry. Do the doors have steel frames? Are the deadbolts bump proof? If you're that worried about break-ins, my advice would be a good renter's insurance policy and a burglar alarm system.

An alternative to bullet-proof could be shatter-resistant. Lexan can be purchased in 4'x8' sheets for $167 at most home improvement stores. You'd probably have to have panels that large (2.5m x 2.5m) custom made though. Be warned that Lexan is not scratch-resistant though, so you may have unbroken but scratched up windows.


If it's a high crime area, the typical solution is window bars on the first floor.

If it's not a high crime area, I'd maybe not panic too much. Most burglaries are through the front or back door or an open window. Smashing large picture windows isn't typically the first choice of a burglar.

  • Window bars would make it feel more like a prison. I have edited my question with regards to the real fear of this happening.
    – David
    Commented Sep 21, 2011 at 17:22
  • Prisons work both ways, +1.
    – Mazura
    Commented Jul 15, 2023 at 1:42

One cheap and easy solution is to simply purchase alarm system stickers/signage from eBay.

A potential burglar won't necessarily know that there's no system installed.

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    I the cost difference would also be something like 1 to several thousand, so its not a bad idea.
    – David
    Commented Nov 29, 2011 at 19:01

The type of glass by itself isn't a deterrent as most burglars don't look first, or they don't know what they are looking at. Signage is a greater deterrent.

The window film as already suggested is most likely the simplest and cheapest solution.

Bullet resistant glass will deter burglars once they throw a brick or take a few swings at the glass and realize that it is still there. This can still break the glass, which will be a very costly replacement. Laminated glass will do a much better job as it will have the same effect. Laminated glass is two pieces of glass bonded together with a plastic. This is how bullet resistant glass is made as well, but with many more layers, thicker glass, and thicker plastic.

The idea of a security film is very similar to why laminated glass is a suitable security glass.


How about getting some electric hurricane shutters? Or get some nice ironwork to function as burglar bars. If you wanted something cheap and fast, get some 2 by 4's, cut them up in a design, screw them together with wood screws, putty them up, route the edges, sand them, a little paint and you have an instant burglar bar.

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    Actually the best bars are aluminum since they break if you hook a rope up to them and drive away, as opposed to pulling the entire frame out
    – Steven
    Commented Nov 26, 2012 at 20:27

We have a very old question here with a bunch of wrong answers with a lot of votes.

Bulletproof windows do not meet any fire safety standards that I know of. They are all restricted by International first safety codes. Installing them or the film would in essence be against code and could cause the homeowner to be liable for a range of issues during a fire.

What makes matters worse is that someone armed would not know if the window was bulletproof so it provides zero deterrent. The easiest thing to do would be to put up metal bars but for a large window and to meet code - this will 100% need to be code because people will see it - it could cost you a TON.

The obvious answer is to frame in part of the first few feet at least and put in new windows. Windows that start higher up off the ground are a very good deterrent. Also whether you own a security system or not putting stickers up is a deterrent as is installing cameras and a motion sensing light. (Getting a working security system is probably recommendable, but again that is not a deterrent it is for after they have broken in)

  • "We now offer several products for applications that require bullet resistance and a fire rating. Pyrostop is a great option with up to 2 hour fire rating and UL 752 Level 3 bullet resistance." fireproofglass.com/fire-ballistic-non-rated - Just talking about fire rating and not the inability to break the glass, right? "a range of issues" ? Any code you can cite?
    – Mazura
    Commented Jul 15, 2023 at 2:01

The best approach is to have multi-layer security.

Paint metal bars to match your siding or paint them white. Put them on the interior so it looks more like a window grid. Once a burglar sees it they most likely won't even try breaking the windows. Put security stickers on the windows, and on top of that use shock sensors.

You really don't have to splurge on bullet proof glass; just use regular glass with the bullet resistant film. If you live in a high crime area consider moving.

Most thieves don't want the attention of shooting off a gun but some will. So even if they do use a gun they will set the alarm off and have the bars to get through.

  • may i know what alarm system can be set off by shooting a gun? Commented Mar 27, 2017 at 2:59
  • @MohammadAli impact sensors on the glass, and there are acoustic gunshot sensors incorporated in some systems. Often college campuses. Commented Jun 25, 2017 at 5:33

How about a custom rolling glass door, like this one in this Our Little Warehome video? It looks good and seems to be a safe alternative.

  • Hello, and welcome to Home Improvement. Why would this kind of door deter burglars? Commented Mar 21, 2019 at 21:12

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