Short answer
Garages are usually opened through something left open or unlocked, a remote in a parked car, or an emergency release hooked from outside. Keep the overhead door closed, secure the release, lock the side door, and treat the door into the house as an exterior door with a deadbolt and an alarm contact.
In this article
How do burglars get into a garage?
Burglars usually get into a garage through an opening someone has already left: an overhead door left up, a remote left in a parked car, an unlocked side door, or a garage window. Some force the overhead door's emergency release from outside. Once inside, the closed door hides them from the street while they work.
The mechanism is less about defeating hardware than about using what the household leaves available. An open garage shows what is inside, and often shows that the car is gone. A remote clipped to the visor of a car parked in the driveway is a working key to the house for anyone who opens the car. Garage side doors tend to have lighter locks than the front door and are usually out of view. Garage windows let someone check whether a car is parked inside, which is one of the quickest ways to judge whether anyone is home.
How does the emergency release make a garage door vulnerable?
The emergency release is a cord that disconnects the door from the opener so it can be lifted by hand during a power outage. On some doors, someone outside can push the top of the door in slightly and hook that cord with a wire, freeing the door. Securing or shielding the release helps close that gap.
The release is a safety feature and should keep working, so the fix is to make it hard to reach from outside rather than to disable it. Options include a shield that blocks access to the release lever from the top of the door, or a fastening that keeps the release from being pulled by a hook while still letting someone inside pull it firmly. The opener manufacturer's instructions are the place to start, since some fastening methods can interfere with safe operation. When the house will be empty for a long time, a slide bolt or padlock on the door track adds a second barrier, as long as nobody tries to open the door with the opener while it is locked.
Remote codes are a smaller concern than they once were. Openers made in recent decades generally use rolling codes that change with each press, while very old openers with fixed codes are easier to copy and are worth replacing.
Why does the door from the garage into the house matter so much?
The door from the garage into the house matters because it is often the weakest exterior door a home has. It is used constantly, frequently left unlocked, and sometimes an interior-grade door. Anyone who gets into the garage can work on it unseen, so it needs a deadbolt, a solid door, and the same attention as the front door.
Families tend to think of this door as being inside the house, because it is behind another door. That is the logic an intruder relies on. Once the overhead door comes down behind them, they have privacy, tools hanging on the wall, and time. A deadbolt with a long strike plate screw set into the framing, a solid-core or metal door, and a habit of locking it at night change that calculation. The same thinking applies to other doors hidden from the street, covered in our guide to securing sliding glass doors.
Can a garage door be connected to an alarm system?
Yes. A tilt sensor or contact on the overhead door reports when it opens, and a contact on the side door and the door into the house covers the other entries. Many systems can also send an alert when the garage is left open, and some openers can be closed remotely from an app.
The left-open alert is often the most useful of these in daily life. Overhead doors get left up after a trip to the car or a delivery, and nobody notices until evening. A sensor that reports the door's position, combined with a reminder or an automatic close, makes that habit less dependent on anyone remembering. Contacts on the interior door give the alarm a second line: even if the garage itself is entered quietly, the house door reports the next step. Which sensors suit a particular garage depends on the door type and how the space is used, and it is the kind of detail settled during professional security system installation.
What does garage security look like in practice?
In practice, garage security means treating the garage as part of the outside of the house: keep the overhead door closed, take remotes out of cars parked outdoors, secure the emergency release, lock and sensor the side door and the door into the house, and cover garage windows. Each step removes one of the usual ways in.
Lighting helps as well: a motion light over the driveway and the side door makes it harder to work there unseen. None of these steps is complicated on its own, and together they turn the garage from an easy route into one more locked door. For the rest of the house, see our overview of how to prevent home break-ins.