What a smart lock really changes
The main benefit is not "no more keys" — it is being able to grant and withdraw access remotely, instantly. A relative, a cleaner, a tradesperson, a short-stay guest: you open an access right and close it again, without a physical key ever changing hands.
The second benefit is traceability. Most models keep a time-stamped log of openings and of the credentials used. For business premises or a rental, that information has real value.
The third is the end of lost spare keys. A code can be revoked, a badge deactivated, a stolen smartphone disconnected from the account. A lost key, on the other hand, means changing the cylinder.
The three main families
Not all smart locks alter your door in the same way, and the choice has direct consequences for how reversible the installation is.
- Motor on the existing cylinder
A motorised unit fixes to the inside face of the door and turns the cylinder for you. The installation is reversible and the key still works from outside. This is the best-suited option for tenants.
- Smart cylinder
The entire cylinder is replaced with an electronic model that reads a badge, a code or a smartphone. The lock body and the door are left unaltered.
- Complete smart lock
Mechanism and electronics integrated in one unit, often with a keypad or biometric reader on the front. The most capable option, but the installation is not reversible.
The limits to understand before buying
Battery life is the first constraint. These locks run on batteries. Serious models warn you well in advance and provide a fallback — a mechanical key, or emergency power from an external battery or a USB connector. Check exactly what that fallback is before you buy: it is what will keep you from being locked out.
Connectivity comes next. Bluetooth means you have to be nearby; remote control requires a Wi-Fi gateway and therefore a working network. An internet outage should never stop you getting into your own home — here again, the mechanical or local fallback is the point to check.
Finally, cybersecurity. A smart lock is a connected device: favour brands that publish security updates and document their encryption, enable two-factor authentication on the associated account, and check how long the manufacturer commits to supporting the software. A product abandoned by its maker becomes a risk.
One point that is often overlooked: mechanical resistance is still that of the door and the mechanism. A smart motor fitted to an ordinary lock does nothing to improve resistance to break-ins. Everyday convenience and break-in security are two separate matters.
Privacy and personal data
A smart lock's access log is personal data: it reveals the occupants' patterns of presence. In a workplace or rental setting, consulting it is not a trivial matter and requires that the people concerned be clearly informed.
Models with biometric recognition process particularly sensitive data. Where possible, prefer devices that store the biometric template locally in the lock rather than on a remote server.
Read the manufacturer's privacy policy before buying: where the data is hosted, how long it is kept, any transfers outside the European Union, whether the history can be deleted. This information should be easy to find; its absence is a warning sign in itself.