How smart locks actually work, the difference between deadbolts and latches, the authentication stack, why smart and connected are not the same thing, and what determines your lock's physical security.
A smart lock replaces or augments your traditional deadbolt or mortice lock, letting you unlock your door using something other than a physical key. The concept is simple. Understanding the details — what changes, what doesn't, and what actually determines security — takes a few more minutes and is worth it before you look at a single product.
Every smart lock contains a traditional locking mechanism — a deadbolt, latch bolt, or mortice bolt — driven by an electric motor rather than a key-turned cylinder. When authentication succeeds (the right fingerprint, the correct PIN, the authorised phone in Bluetooth range), the motor drives the bolt in or out. The bolt itself is identical in function to a conventional lock: it projects into a strike plate in the door frame, and physical resistance to that bolt is what provides security.
This is the most important thing to understand about smart locks: the electronic features are access management tools. They determine who can open the door. They do not make the door harder to force open. A door that can be kicked in with a traditional lock can be kicked in with a smart lock. Physical door security — frame strength, strike plate fixings, hinge quality, door construction — is unchanged by fitting a smart lock.
Tubular Deadbolt
The bolt is square-ended and moves only when explicitly commanded — there is no spring mechanism. A deadbolt must be actively locked after the door closes. It does not self-lock.
High forced-entry resistance. Recommended for all external doors. The correct choice for your front door, back door, or any door separating secure from unsecured space.
Most residential smart locks are deadbolts.
Tubular Latch
Spring-loaded angled bolt that retracts automatically when the door closes. Auto-latching is convenient for internal doors where you want the door to hold closed without a deliberate lock action.
Lower forced-entry resistance than a deadbolt. Not recommended as the sole security mechanism on any external door.
Appropriate for: bedroom, office, or storeroom internal doors.
The above are tubular bolt types. Many smart locks — particularly commercial and European-style installations — use a mortice lock body instead, set into a rectangular pocket in the door edge. Mortice versions of both deadbolt and latch are available.
Mortice Deadbolt
A square-ended deadbolt housed inside a mortice lock body that sits in a rectangular pocket routed into the door edge — not a round borehole. Common in commercial buildings, older Australian homes, and European-style doors.
High forced-entry resistance. Requires a mortice-specific smart lock — do not attempt to fit a tubular lock into a mortice prep. Professional installation required.
Mortice Latch
A spring-loaded angled bolt in a mortice lock body. Auto-latches when the door closes. Used on doors where a mortice prep already exists and a tubular latch is not appropriate. Common in commercial and heritage residential applications.
As with all latches — lower forced-entry resistance than a deadbolt. Not recommended as the sole security device on any external door.
Smart lock authentication works in layers. A single lock typically supports several methods simultaneously. Understanding each layer matters for planning your backup access strategy — every layer has a failure scenario, and a well-configured smart lock has multiple working methods at all times.
| Layer | Method | Works Without Internet? | Primary Failure Mode |
|---|---|---|---|
| Primary |
Fingerprint, PIN, or Face scan
|
✓ Yes — validated on the lock | Wet fingers / forgotten PIN / face change |
| Secondary |
Bluetooth app (phone in range)
|
✓ Yes — direct phone-to-lock | Dead phone / Bluetooth off |
| Remote |
WiFi app (anywhere via gateway)
|
✗ No — requires internet | Power outage / router down / server outage |
| Override |
Physical key cylinder
|
✓ Always — mechanical | Lost key / seized cylinder |
Authenticates access via electronics rather than a key. Can work entirely offline. Most smart locks fall into this category at their core.
Fingerprint
PIN
RFID
Face
Bluetooth
No internet required. No gateway required. Simpler, lower battery usage, more reliable.
Linked to your home WiFi via a gateway hub, enabling remote access and management from anywhere. Adds audit trail, push notifications, and remote user management on top of the smart lock's core features.
WiFi
App
Requires a gateway, WiFi, and active internet. Adds cost and complexity. Only necessary if remote access is a genuine requirement.
Many buyers assume a smart lock needs to be connected to a network to function. It does not. A fingerprint lock that works entirely offline — no WiFi, no app, no gateway — is still a fully functional smart lock. Decide whether you genuinely need remote connectivity before you start comparing products.
Almost all residential smart locks run on standard AA batteries — typically four to eight cells, providing 6–18 months of operation depending on usage and connectivity. This is intentional: battery power means no electrician, no mains wiring, no cable running to the door, and no dependency on the power grid. A battery-powered smart lock continues to work perfectly during a power outage.
Hardwired (mains-powered) smart locks exist for commercial applications but are uncommon in Australian residential installations. If a product requires mains power, confirm this before purchasing — it significantly changes the installation requirements and cost.
| What Changes | What Stays the Same |
|---|---|
| How you authenticate to unlock — fingerprint, PIN, card, phone, or face instead of a key | Your door frame, strike plate, and hinges — these determine physical forced-entry resistance |
| How you manage access — add or remove users instantly via app, no rekeying required | The bolt mechanism and security rating — SL2 is SL2 whether it's a traditional or smart lock |
| What you know about access — audit trails show who opened the door and when | The installation requirements — a smart lock still needs to fit your door prep correctly |
| Guest and temporary access — time-limited codes replace physical key cutting | The need for a backup access method — always configure at least two methods |
The next chapter covers the six measurements you need to take before ordering any smart lock — the step most buyers skip and most regret.
