Smart Locks Explained

Smart locks solve a real problem - fumbling for keys, giving a tradesperson temporary access, never re-keying after a flatmate moves out. But the single most important thing to check before buying one has nothing to do with features: it's whether it physically fits your door.

What a smart lock actually replaces

Most smart locks on the market don't replace your whole door lock — they replace or retrofit onto your existing deadbolt, adding a motor that turns the bolt electronically. You unlock it with a code on a keypad, a tap in an app over Bluetooth or Wi-Fi, a fingerprint on models with a scanner, or a physical key kept as backup for when the battery dies or the electronics fail. Almost every reputable smart lock keeps a mechanical key override for exactly that reason — don't buy one that doesn't.

The unlocking methods, honestly assessed

• Keypad code: reliable, no phone needed, good for giving temporary codes to cleaners or guests. Downside: codes can be shoulder-surfed, and battery-powered keypads eventually need new batteries.
• App / Bluetooth / Wi-Fi: convenient once set up, lets you lock remotely and see access logs. Downside: adds a dependency on your phone being charged and in range, and Wi-Fi locks add another device to your home network's attack surface.
• Fingerprint: fast and doesn't need you to carry anything. Downside: can be finicky with wet or dirty hands, and adds cost.
• Physical key backup: the fallback that should always exist. Treat any smart lock without one as a liability.

Retrofit vs full replacement

Two broad approaches exist. Retrofit locks (like August-style models) clip onto your existing deadbolt from the inside, leaving the outside of your door untouched — simplest install, but limited by your existing hardware's compatibility. Full-replacement smart locks swap out the entire lock body, keypad and all, giving more design flexibility but usually needing more precise fitting and sometimes professional installation. In New Zealand, full-replacement smart deadbolts sized for local door standards (from brands with proper AU/NZ distribution) are generally the safer bet than assuming a US import will drop straight in.

Battery life and what happens when it dies

Most smart locks run on standard AA or coin-cell batteries and last anywhere from four months to a year depending on usage and whether Wi-Fi is built in (Wi-Fi radios drain batteries noticeably faster than Bluetooth-only or Zigbee-bridged models). Nearly all give a low-battery warning through the app or an audible alert well before they die, and the mechanical key backup means a dead battery is an inconvenience, not a lockout — provided you haven't lost the physical key.

Security: can they be hacked?

It's a fair question, and the honest answer is: any networked device has a theoretically larger attack surface than a plain mechanical lock, but in practice, reputable smart locks with proper encryption are not an easy target for a random burglar — physical attacks (kicking the door, attacking the frame, or simply picking a low-quality mechanical cylinder) remain far more common break-in methods than anything digital. The bigger practical risk is usually user error: sharing codes carelessly, or leaving default settings unchanged. Buy from established brands with a track record of security updates, keep firmware current, and don't rely on a smart lock as your only security measure — pair it with good door and frame hardware.

Do insurers care?

Most NZ home insurers don't specifically require or reward smart locks the way some insurers overseas do with monitored alarm systems — check your policy wording, but a smart lock generally needs to meet the same "adequate lock" standard as a normal deadbolt to satisfy security clauses, not more. If your insurer has minimum lock standards (common for older villas with weak original hardware), confirm your chosen smart lock meets them before relying on it for a claim.

Do you actually need one?

If you're constantly juggling keys for family, cleaners, or short-term guests, or you like the idea of remote access logs and temporary codes, a smart lock is genuinely useful. If you live alone, rarely have visitors needing access, and your current deadbolt works fine, it's a nice-to-have rather than a must-have — the main practical win (remote code management) only pays off when multiple people need varying access.