Garage-to-House Door Lock: How to Secure the Door Into Your Home

The door from the garage into your house is often the weakest door in the home. It usually has just a knob lock, and it’s often left unlocked. The biggest upgrade is adding a deadbolt with a strong strike plate and long screws, then rekeying it to match your house key so it gets locked every time.

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Why the garage-to-house door matters

People lock the front door but often forget the door from the garage into the house. If someone opens the overhead door with an old remote or code, or gets in through the garage’s side door, this door is the last thing between them and your home. A basic knob lock with short strike screws is easier to force than a deadbolt.

The same advice applies to a garage side door that opens to the yard.

What to upgrade

• Add a deadbolt. A deadbolt throws a solid bolt into the frame. Bill’s video above shows how to install a deadbolt on a door that doesn’t have one.
• Strengthen the strike. Use a heavy-duty strike plate and long screws that reach the framing behind the door jamb.
• Check the door itself. A deadbolt can only be as strong as the door and frame it’s installed in. Damaged or rotted doors and frames should be repaired.
• Exterior screws: hinges with exposed pins on the outside can be a weak point. Security hinge pins or set screws help.

Replace the lock

1. Measure the backset (door edge to the center of the hole) and the door thickness, and check the hole size.
2. Buy a knob or lever and deadbolt that fit those measurements, or a combo pack keyed alike.
3. Remove the old lock (screws on the inside), then the latch from the door edge.
4. Fit the new latch with the slanted side facing the strike, then the knob or lever.
5. Install the deadbolt, then test everything with the door open and closed.

The deadbolt install guide covers the deadbolt in detail. If the door won’t latch after the swap, see door won’t latch.

Match your house key

If the new lock takes the same keyway as your house locks, it can often be rekeyed to your existing key. See rekey a lock to match your key.

Before you change this door

Treat the garage-to-house door like an exterior door with a deadbolt. Check local rules before replacing the door itself, since some areas have requirements for doors between a house and garage. If you have a garage door opener, change old remote and keypad codes too. Lock options for the overhead door are covered in garage door lock options.

Quick checklist

• Deadbolt installed and throwing fully
• Heavy-duty strike with long screws
• Hinge pins secure
• Door and frame solid