It depends on the window. We don’t usually leave windows open, and crank windows are harder to pry open. If they’re wooden and rotting, that’s a different story.
To properly cover your house, you need a sensor on every window and glass break detectors every 20 feet or for a group of windows. Motion detectors don’t work well when you’re home, and by the time they go off, someone’s already inside. Cover all your bases.
I only put sensors on windows that are likely entry points. For example, I didn’t bother with second-story windows right above first-floor ones. The most important ones are doors and windows at ground level or out of sight from the street.
It depends on what you want. Some people prefer glass break detectors, while others like motion sensors. My wife wanted sensors on every window and door, plus a couple of motion detectors. We waited for a sale to buy everything since it adds up.
Thieves can sense when a window doesn’t have a sensor.
That said, it comes down to how safe you want to feel. You could cover the whole room with motion detectors or infrared sensors.
Get some sensor lights outside, motion detectors inside, and put alarm company stickers on your windows. That should make burglars go next door instead.
Glass break detectors are easier, and you won’t need as many sensors.
I have double-hung windows on the ground floor with pins to prevent them from being lifted, along with glass break detectors. My installer recommended it, and I wouldn’t argue against putting sensors on all first-floor windows.
What’s your goal? A good security setup uses layers, like recessed sensors on all windows, glass break detectors, and well-placed motion detectors inside.
You’ve gotten a lot of good advice, but I’ll add my two cents:
If money is tight, start with sensors on the main entry points, especially where someone might feel hidden. Don’t underestimate a burglar’s climbing skills—some of them are like cats. Motion detectors are always a good idea if you can add them.
Also, think about using outdoor wired cameras with human detection and a good notification setup. This might help you save on sensors while still covering a lot of windows, and it’ll also help scare off thieves.
What’s your area like? What’s your budget? We usually keep it simple: motion detectors in each room and hallway, and a contact sensor on each exterior door.
Motion detectors aren’t great if you have pets or want to arm the system while you’re home. It’s better to invest in window contacts.