Smart Deadbolt

Both halves of the lock come out and both halves get replaced. Outside you fit a plate carrying the keypad, reader or cylinder. Inside you fit a housing holding the motor, the gearbox and four AA cells; between them runs a new bolt. Standard North American door prep suits it: a 2-1/8 inch (54 mm) cross bore through the face, a 1 inch edge bore, and a backset of 2-3/8 or 2-3/4 inches (60 or 70 mm) that most models switch between. Budget 20 to 40 minutes with a Phillips screwdriver.

Replacing everything is what separates this from a Retrofit Deadbolt Adapter, which reuses your existing cylinder and can only ever be as good as the lock underneath. A Keypad Deadbolt is often the same body with the radios left out. A Smart Lever Handle holds a spring latch instead of a bolt, so it never reaches this level of resistance. Because you choose the whole assembly here, you also choose its rating, its bolt length and whether a keyway exists at all.

Owners of a front door make the clearest case, especially when several people need their own way in and the old lock is due anyway. Going fully keyless removes picking and bumping from the list of ways in, at the price of never being able to open the door with a dead battery and nothing else. Skip this style in a rental unless your landlord agrees in writing, and skip it on a door thicker than 1-3/4 inches (44 mm) without checking for an extension kit.

Check the ANSI/BHMA grade, the North American durability and force standard: Grade 1 for an exposed entry, Grade 2 for most homes, Grade 3 only indoors. A 1 inch bolt throw is the number that matters more than the finish. Ask for the operating temperature range if the door faces weather, look for a physical tamper alarm, and confirm the emergency power path, whether that is a key, 9V contacts or a USB-C port.

Set the two long through-bolts snug and no tighter, because over-tightening pinches the spindle and makes the motor work against you every cycle. Replace the strike plate screws with 3 inch screws that reach the framing. Test the bolt by hand with the door shut each spring and fall.