Will a smart lock fit my existing door?

Almost certainly, if it is a standard exterior door. Smart deadbolts are built for the two universal North American bore sizes: a 2-1/8 inch face bore and a 1-inch edge bore, with a backset (center of hole to door edge) of either 2-3/8 or 2-3/4 inches. Most locks include an adjustable latch that covers both backsets. Measure your door thickness too; the standard range is 1-3/8 to 1-3/4 inches, and thicker doors may need an extension kit. Mortise locks and narrow-stile glass doors are the main exceptions.

Do I need to drill new holes for a smart lock?

No, for a like-for-like deadbolt swap. A smart deadbolt reuses the existing bore holes, so you remove the old deadbolt and mount the new one in the same openings with just a screwdriver. You only drill if you are adding a deadbolt where none exists, which requires a bore kit and jig and is a bigger job. If your smart lock is a retrofit that keeps your existing exterior deadbolt and only replaces the interior thumbturn, you drill nothing at all.

Why won't my smart lock bolt fully after installation?

The most common cause is latch or strike misalignment, meaning the bolt is hitting the strike plate instead of sliding into the hole. Confirm the latch is oriented correctly (the slanted face of a spring latch faces the door frame; a deadbolt has no slant) and that the tailpiece engages the motor. If the bolt binds partway, the strike hole in the frame is slightly off; enlarge or file it, or shim the strike plate. A motor that grinds and retracts usually means the two halves are over-tightened and pinching the spindle.

Are smart locks secure, or can they be hacked?

The physical security of a quality smart deadbolt matches a traditional one, since the bolt and strike are the same hardware. The digital risks are weak passcodes, reused Wi-Fi credentials, and outdated firmware, not someone remotely picking the lock. Use a unique code, enable two-factor authentication on the app account, keep firmware current, and delete guest codes you no longer need. For a deeper look at the real versus imagined risks, our guide on whether smart locks can be hacked walks through what actually matters.

Do smart locks work when the batteries die or Wi-Fi goes down?

Most keep a physical key override or an external keypad that runs on the lock's own batteries, so a Wi-Fi outage never locks you out of a deadbolt, it only pauses remote control. Battery life is typically 6 to 12 months, and locks warn you well before they die, often with a red light and app alert for weeks. Some models add emergency 9-volt contacts on the exterior so you can jump power to enter if the internal batteries are fully dead. Keep a spare set of AA batteries nearby.

How to Install a Smart Lock (DIY, Step by Step)

Written & researched by Derek Holt Home & Appliances Editor

Updated August 2026

Close-up detail of the material being worked in a smart home & security project, in bright midday sun

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Installing a smart lock is one of the easiest smart-home upgrades: about 30 minutes, one Phillips screwdriver, and no wiring. A smart deadbolt reuses your existing bore holes, so you are swapping hardware, not cutting the door. Cost is just the lock ($90 to $300). There is nothing electrical or structural involved, so no permit and no pro are needed for a standard exterior door. The only measurements that matter are backset, door thickness, and getting the latch aligned so the bolt throws cleanly.

How to Install a Smart Lock and Deadbolt — Lowe's

Measure before you buy

Three numbers decide fit. Backset: from the door edge to the center of the bore hole, either 2-3/8 or 2-3/4 inches. Door thickness: standard is 1-3/8 to 1-3/4 inches. Bore diameter: the face hole is almost always 2-1/8 inches. Most smart deadbolts adjust to cover both backsets and the standard thickness range. Confirm these before ordering.

Close-up detail of the material being worked in a smart home & security project, in warm late-afternoon light

Step-by-step installation

Remove the old deadbolt. Unscrew the two screws on the interior thumbturn, pull both halves off, then remove the two screws holding the latch in the door edge and slide the latch out.
Set the new latch backset. If the latch is adjustable, set it to your measured backset (2-3/8 or 2-3/4 inches). Slide it into the edge bore with the beveled or flat face oriented per the instructions, and screw it in flush.
Mount the exterior half. Feed the exterior keypad or cylinder through the face bore so its tailpiece or spindle passes through the slot in the latch.
Attach the mounting plate and interior half. Fit the interior mounting plate, then the interior body with the motor and battery pack. Do not fully tighten until you confirm the bolt turns.
Test the throw by hand. Turn the thumbturn. The bolt should extend and retract smoothly. If it grinds, back the screws off slightly — over-tightening pinches the spindle.
Check strike alignment. Close the door and throw the bolt. It should slide into the strike hole without lifting or forcing the door. If it catches, file the strike hole or reposition the strike plate.
Install batteries and pair. Load the AA batteries, then run the app's guided setup over 2.4 GHz Wi-Fi or the lock's own hub. Calibrate the lock/unlock direction and set your first code.
Set codes and delete the default. Create a unique personal code, add guest codes as needed, and remove any factory default code.

Wide view of a person mounting a small camera beside a front door, in bright midday sun

Tools and materials

You need only a #2 Phillips screwdriver, the AA batteries the lock uses, and a tape measure for the initial fit check. A file or utility knife helps if the strike needs adjusting. A smart lock is the entry layer of a connected home, so it pairs naturally with a doorbell and cameras — see our smart lock picks for models with the best owner-reported reliability, and our video doorbell roundup if you want to see who is at the door before you unlock. To tie codes and alerts into one app, our DIY security system guide covers compatible hubs.

Golden-hour view of a person mounting a small camera beside a front door

Mistakes that cause a jamming bolt

Wrong backset. If the adjustable latch is set to the wrong length, the bolt never lines up with the strike. Measure and set it first.
Over-tightening. Cranking the mounting screws pinches the spindle and stalls the motor. Snug, then test, then final-tighten.
Ignoring strike misalignment. A bolt that only throws when you lift the door means the strike hole is off. Fix the strike, not the lock.
Keeping the default code. Leaving the factory code active is the real security hole. Replace it immediately.

When to call a pro

A standard deadbolt swap needs no pro. Call a locksmith or carpenter if you have a mortise lock, a narrow-stile aluminum-and-glass door, a door with no existing deadbolt bore (which requires drilling with a jig), or a warped door where the bolt will not reach the strike no matter how you adjust it. None of this is electrical work, so an electrician is not involved; it is a fit-and-carpentry question when the door itself is nonstandard.

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How to Install a Smart Lock