Can I put an alarm sensor on the overhead garage door itself?

Yes. Wireless contact sensors can be mounted on the door's top panel with the magnet on the frame, so opening the door breaks the contact and triggers the system. Check your system's guidance for overhead or tilt-door mounting, and test it through a few open-close cycles, since large metal doors flex more than a normal door.

Is the emergency release cord really a break-in method, and can I remove it?

The fish-and-pull technique exists, and simple shields that block outside access while keeping the release usable from inside are the right fix. Do not remove or disable the release. It is a safety mechanism for power failures and entrapment, and a garage you cannot open from inside is a hazard.

What does it cost to add a garage to an existing alarm system?

For an attached garage on a wireless system, typically one or two entry sensors and optionally a motion sensor. By SimpliSafe's published pricing as of August 2026 that is $15.99 per entry sensor and $34.99 for a motion sensor, so roughly $32 to $67 in parts before any camera.

Should the garage camera go inside or outside?

Outside covering the driveway approach does more, because it sees activity before entry and covers vehicles too. An interior camera is a reasonable second position if the garage stores high-value tools or bikes. Either way, mount high and check the night-time image, since headlights and IR reflections off a white door can wash out cheap cameras.

Does a security sign on the garage help?

Signs and visible cameras are deterrence inputs, not barriers, and the evidence on how much they deter is mixed. We walk through what burglar surveys actually say in [do security signs deter burglars](/guides/do-security-signs-deter-burglars). Treat signage as a cheap supplement to closed doors and locked interior doors, never a substitute.

Garage Security: Closing One of the Weakest Doors in the House

Garage break-ins typically exploit convenience failures: an overhead door left open, an opener remote sitting in a parked car, or an unlocked side door. Fix the habits first, then add hardware: a contact sensor on the overhead door and the side door (from $15.99 each by published SimpliSafe pricing as of August 2026), a deadbolt on the door between garage and house, and a camera covering the driveway approach. Treat the garage-to-house door as a real exterior door, because once someone is inside the garage they can work on it unseen.

Figures researched 2026-08-19; each source below carries its access date. Prices change; treat any price here as "as of" its date.

How garages actually get burglarized

The common garage entry paths are unglamorous:

The open door. The classic failure is an overhead door left open, whether for ten minutes or all night. Everything visible from the street (tools, bikes, the door into the house) becomes an advertisement.

The opener remote in the car. A remote clipped to the visor of a car parked in the driveway is a key to your garage sitting behind one pane of tempered glass. Anyone who breaks into the car can open the garage at leisure, often days later. Carry the remote on your keychain or use your car's built-in transmitter, and treat a stolen or lost remote like a lost house key: erase and re-pair the opener.

The side (man) door. Garage side doors are often the cheapest door on the property, with a builder-grade knob lock, no deadbolt, and no lighting. They get less attention than the front door and offer more cover.

The emergency release pull. The red cord on the opener trolley can sometimes be fished through the top of the door and pulled from outside. Simple shields and zip-tie techniques that keep the release functional from inside are widely used; do not remove or permanently disable the release itself, because it is the mechanism that lets you open the door in a power failure or if someone is trapped under the door.

One structural fact drives the whole topic: in an attached garage, the door from garage to house is usually a hollow-core or lightly locked interior-grade door, and an intruder who gets the overhead door down behind them can attack it with total privacy. That door deserves exterior-door treatment: solid core, deadbolt, reinforced strike.

Hardware that closes the gaps

Contact sensors on every garage door. A standard entry sensor works on the side door, and most wireless systems also support mounting one on the overhead door itself (on the top panel, or via a purpose-made tilt orientation) so the system knows when the big door opens. SimpliSafe's Entry Sensor is $15.99 as of August 2026 by published pricing; two or three cover a typical garage. If your system is armed at night, a garage door opening at 3 a.m. becomes an alarm instead of a surprise.

A motion sensor inside. A single motion sensor ($34.99 by SimpliSafe published pricing as of August 2026) covers the interior regardless of how someone got in, and backstops the case where the overhead door is defeated without fully opening.

A camera on the driveway approach. Mount it high, covering the overhead door and driveway. Wired or plug-in options work if the garage has power; SimpliSafe's Outdoor Camera is $199.99 by published pricing as of August 2026, and wire-free solar units like the eufy SoloCam S220 ($99.99 as of August 2026, requires 2.4 GHz Wi-Fi reach) avoid running cable. If you do not want a subscription attached to the footage, the local-storage options in no-subscription security cameras apply directly here.

Deadbolt the interior door. A deadbolt and a strike plate with 3-inch screws on the garage-to-house door is the cheapest high-value upgrade in this whole piece. Keep it locked whenever the car is not actively coming or going, including when you are home.

Light the side door. A motion-activated light removes the cover that makes side doors attractive. It costs little and requires no system integration.

One safety note: never block, lock, or booby-trap the garage's pedestrian exits in a way that slows escape from inside. The garage is also where cars, fuel, and chargers live, and you may need to get out of it fast.

Smart openers and daily habits

Smart garage door controllers (native in some newer openers, add-on modules for older ones) send an alert when the door opens and let you close it remotely. Their honest value is the open-door notification: the failure mode they eliminate is 'did I leave the garage open?', which is the garage security failure that needs no burglar at all. If you buy one thing for an attached garage, an alerting controller or a contact sensor on the overhead door does more than any lock.

The habits matter as much as the hardware:

Close the overhead door whenever the garage is unattended, even briefly, even while mowing the back yard.
Keep the interior door locked so the garage is a buffer zone, not a bypass.
Frost or curtain garage windows so contents are not on display.
Do not leave the opener remote in a driveway-parked car overnight.
If the garage holds bikes, anchor and lock them as if they were parked on the street; a garage stores the same theft targets as a shed, just closer to the house.

A garage on a detached structure has a different problem set (no house alarm nearby, often no Wi-Fi or power), which we cover separately in detached garage and shed security.

Frequently asked questions

Can I put an alarm sensor on the overhead garage door itself?: Yes. Wireless contact sensors can be mounted on the door's top panel with the magnet on the frame, so opening the door breaks the contact and triggers the system. Check your system's guidance for overhead or tilt-door mounting, and test it through a few open-close cycles, since large metal doors flex more than a normal door.
Is the emergency release cord really a break-in method, and can I remove it?: The fish-and-pull technique exists, and simple shields that block outside access while keeping the release usable from inside are the right fix. Do not remove or disable the release. It is a safety mechanism for power failures and entrapment, and a garage you cannot open from inside is a hazard.
What does it cost to add a garage to an existing alarm system?: For an attached garage on a wireless system, typically one or two entry sensors and optionally a motion sensor. By SimpliSafe's published pricing as of August 2026 that is $15.99 per entry sensor and $34.99 for a motion sensor, so roughly $32 to $67 in parts before any camera.
Should the garage camera go inside or outside?: Outside covering the driveway approach does more, because it sees activity before entry and covers vehicles too. An interior camera is a reasonable second position if the garage stores high-value tools or bikes. Either way, mount high and check the night-time image, since headlights and IR reflections off a white door can wash out cheap cameras.
Does a security sign on the garage help?: Signs and visible cameras are deterrence inputs, not barriers, and the evidence on how much they deter is mixed. We walk through what burglar surveys actually say in [do security signs deter burglars](/guides/do-security-signs-deter-burglars). Treat signage as a cheap supplement to closed doors and locked interior doors, never a substitute.

Sources

SimpliSafe Entry Sensor $15.99, Motion Sensor $34.99, Outdoor Camera $199.99: https://simplisafe.com/alarm-sensors (accessed 2026-08-19)
eufy SoloCam S220 $99.99, solar-charged, 2K, requires 2.4 GHz Wi-Fi: https://www.eufy.com/products/t8134121 (accessed 2026-08-19)