It's a jungle out there. Are your windows burglary-resistant? Or, to put it another way...fortified? Remember, burglars (and rapists) LOVE windows. This includes second-story windows. Don't assume that you don't need to fortify second-story windows or those that are high off the ground. Some home intruders don't mind pretending to be Spiderman.
These films will make it difficult for a burglar to bust though the window. The films are easy to install and are sold in a variety of thicknesses. The film will slow down the most determined hoodlum, giving you time to take action, or making him give up more easily. The film also prevents the problem of shards of glass spilling everywhere should the window be busted.
No, not like what a prison has, but stylish and aesthetic metal designs that are too strong for a human to rip apart and get through. This type of fortification will also prevent toddlers and babies from falling out of windows (there's already too much of that in the news lately).
Hurricane Security Screen
These aren't cheap, but you'll get what you pay for. They look a lot nicer than the traditional metal bars, too. They come in different thicknesses and sizes, and the thicker and stronger varieties cost more. But if you have the money and want the security, go for it.
Cut plywood to fit all of your windows. Install the panels behind curtains, but you may also want to also install the plywood on the outside. Carriage bolts will yield a more enhanced fortification.
On double-hung windows, install a locking pin that goes through the first sash and into the other sash which prevents intruders from lifting the sash.
Cut 2x4s the lenth of the space above the bottom sash. When installed, it prevent the bottom sash from being pried open.