Smart lock installation, fitted right

What to know before you call

Smart locks are sold as a simple swap, and on a well-aligned door they often are. The trouble starts when the door sags, the bolt drags in the strike, or the new lock doesn't fit the existing holes — a motorized bolt that can't fully extend may report "locked" when it isn't.

A locksmith makes sure the door, bolt and strike are aligned so the lock can do its job, and can fit the lock to doors that need new holes or adjustments.

Check the fit before you buy

Most residential doors are drilled to a common standard, but not all. The distance from the edge of the door to the center of the lock hole (the backset), the hole size and the door thickness all need to suit the lock you choose. A locksmith can measure the door and recommend a lock that fits — or adjust the door to fit the lock you want.

Keep a backup way in

Smart locks run on batteries and some depend on Wi-Fi or a phone app. Most models keep a physical key cylinder or an external power option for exactly that reason. Keep the backup key somewhere you can reach it, and swap batteries when the lock warns you.

Codes instead of copies

One of the best reasons to go smart: you can give a dog walker, cleaner or guest their own code and delete it when they're done. No keys to collect and nothing to rekey.