What a smart door lock does, and what it replaces
A smart lock does the same job as the lock you have now: a bolt holds the door shut. What changes is how the bolt moves. Instead of a key, the lock checks a fingerprint, a code, a card or a signal from your phone, then moves the bolt itself. Shops also sell it as a digital door lock, an electronic door lock or a keyless door lock.
Smart locks come in two main kinds. The first fits over the existing lock on the inside of the door, turns it with a small motor, and usually keeps your key working from outside. It is quick to fit and easy to remove, which suits a rented flat. The second replaces the whole lock: a new body inside the edge of the door, a handle on each side, and a keypad or fingerprint reader on the outside. It takes more work to fit, but it puts every way of opening on the outside panel.
Some models add a camera, a doorbell and a small screen, sold as a smart lock with camera. It shows who is at the door and records a clip when someone rings or comes close. It usually runs on batteries, so it does not record all the time like a CCTV camera, and it adds to a camera system rather than replacing it.
Fingerprint, code, card or phone: choosing how the door opens
A fingerprint door lock suits the family who live in the house. Nobody carries anything, and a fingerprint cannot be lent or copied at a key shop. The reader works best with clean, dry fingers, so enrol two fingers for each person. Expect it to struggle with wet hands after the pool, dusty hands after gardening, and the small fingers of young children.
A code suits people who come and go, such as a driver, a cleaner or a guest. Each person can have their own, and deleting one leaves the others working. Many smart locks accept extra digits before or after the real code, so the marks on the keypad do not give it away. A card suits children, and a lost card can be deleted so that it opens nothing.
The phone app opens the door over Bluetooth or Wi-Fi. Face recognition opens the door hands-free, which helps when you carry shopping, but it uses more power and costs more. Whatever you choose, keep at least two ways in, and make one of them independent of the battery, such as the mechanical key.
- Nothing to carry or lose
- No copies cut at a key shop
- Struggles with wet or dusty fingers
- Suits the family who live there
- One code for each person
- Easy to delete or change
- Can be watched or passed on
- Suits drivers, cleaners and guests
- Opens over Bluetooth near the door
- Opens from anywhere over Wi-Fi
- Depends on the phone and its battery
- Suits sharing access from abroad
The door decides the lock: wood, metal, aluminium and glass
Before you compare features, look at the door. Each smart lock's specifications list the door thickness it fits, and a full replacement also gives the size of the lock body that goes inside the edge. A wooden door is the simplest case, because its cut-out can be enlarged. A metal front door on a villa often has a lock body and handle holes made for its own lock, so the new lock must match them, or new holes must be cut in steel.
Aluminium and glass doors are harder. Their frames are narrow, so they need a slim lock body made for them, and a frameless glass door needs a lock designed to clamp onto the glass. A sliding door needs a model with a hook bolt, and a double door needs its second leaf held shut at the top and bottom. Check which way the door opens, inward or outward, left or right, since the lock is set for that side.
Measure the door, or photograph both sides and the edge, before you buy. If you rent, agree the change with the landlord and keep the old lock to refit when you leave. On an outdoor gate, choose a lock rated for rain and dust. Keep its keypad out of direct sun where you can, because the sun heats the panel and makes a screen hard to read.
Smart lock batteries, power cuts and getting in when they die
Most smart locks run on batteries, usually standard AA cells or a rechargeable pack, so a power cut does not lock you out. A set lasts months, depending on how often the door opens and whether the lock uses Wi-Fi, which draws more power. Before the batteries run flat, the lock warns you with a beep at the door and, if it is connected, a message in the app. Replace the whole set at once, and keep spares at home.
If the batteries do die, there are two ways in. Many locks have an emergency power point on the outside, a USB socket or contacts for a 9-volt battery, which wakes the lock long enough to enter a code or a fingerprint. Many also keep a mechanical key. Keep that key where you can reach it from outside, with a relative or a neighbour you trust, never under the mat.
Batteries in the inside half of the lock stay out of the sun and dust. Heat shortens battery life, so a lock on a door in full UAE summer sun needs new batteries sooner. A porch over the door helps the lock as much as the visitor.
Wi-Fi, Bluetooth or a bridge: what works without internet
How the lock connects decides what you can do from your phone. A Bluetooth lock talks to your phone only a few metres from the door: it opens from the app when you are close, but you cannot open it from abroad or get alerts. A lock with built-in Wi-Fi can do both, and it sends alerts when the door opens, but it uses more battery and needs a good signal at the door. Many locks solve this with a small bridge plugged in near the door, which links them to the home Wi-Fi.
At the door itself, the connection makes no difference. Fingerprints, codes, cards, the key and Bluetooth keep working when the internet is down, because the lock checks them on its own. What stops is anything that needs the lock online: opening from abroad, alerts, and changes sent to the lock from the app. Ask which of these the model can do offline, and test the Wi-Fi signal at the door.
A smart lock can also join the rest of the house. With a compatible model, a video intercom can open it from the monitor or your phone. A smart home system can also run a scene when it opens, such as turning on the hall lights. Settle the link before you buy, because the lock and the system must support each other.
Smart lock codes for guests, workers and holiday homes
The biggest gain over a key is control over who can get in. Give each person their own fingerprint, code or card, and the log shows who opened the door and when. On many smart locks, a cleaner who comes twice a week can have a code that works only on those days. A guest for a weekend can have one that ends when they leave. Nobody needs to hand back a key, and nobody keeps a copy.
For a holiday home, or a flat you let to short-stay guests, this is the main reason to fit one. Each booking can get a new code that starts at check-in and stops at check-out, sent from the app before the guest arrives. Some models create these codes in the app while the lock is offline; others need it online through Wi-Fi or a bridge.
Access has to be removed as carefully as it is given. When a worker leaves, delete their code, fingerprint and card on their last day, and review the list of users every few months. Avoid one shared code for everyone, because then the log cannot tell you who opened the door. Tell the household that the lock keeps a log.
How safe is a smart door lock?
A smart lock is as strong as the lock underneath it. The electronics decide who may open the door, while the bolt, the lock body and the key cylinder decide how hard it is to force. The cylinder for the backup key matters as much as the keypad, so ask about it too. Then set it up well: change the default admin code, turn on auto-lock, let it sound an alarm after several wrong attempts, and keep its firmware current.
Protect the app as you would a bank account, with a strong password and two-step sign-in, because whoever holds the account holds the keys. Fingerprints are usually stored as a pattern of points, not as a picture. Ask whether the model keeps them in the lock or in the cloud, and who can see the log.
Keeping intruders out is only half the job; the people inside must be able to get out. From inside, the door must open in one movement, with the handle or a thumb-turn, without a code, a key or power. That is how everyone gets out quickly in a fire, including children and older family members. Avoid any setting that locks the inside handle, and test the door at handover with the batteries taken out.
What decides the price of a smart door lock
Smart door locks have no single price, because the door and the features set most of it. The first cost is the lock itself: one that fits over the existing lock usually costs less than a full replacement, and a camera, a screen or face recognition adds to it. The door comes next. A wooden door with a standard cut-out is the simplest job, while a metal, aluminium or glass door may need a body made for it, new holes or an adapter plate.
The number of doors comes next, since a front door, a back door and a gate can share one app. Then comes the connection: a Wi-Fi bridge, or a link to an intercom or a smart home system. Fitting and setup make up the rest: aligning the bolt with the frame, testing the inside handle, and enrolling every user. Compare quotes on the same lock type, the same doors and the same functions.
We look at the doors first, from photos or a visit, to see what each one is made of and how it is locked today. We then choose the lock and the setup with you, and quote one fixed price for that scope before any door is drilled.
- 01List the doors and who uses themThe front door, the back door and the gate, and everyone who uses them.
- 02Check each doorWhat it is made of, how thick it is and how it is locked today.
- 03Choose how each person opens itFingerprints for the family, codes for workers and guests, a key as backup.
- 04Decide how the lock connectsBluetooth at the door, or Wi-Fi or a bridge for control from abroad.
- 05Fit the lock and test the inside handleThe bolt meets the frame cleanly, and the door opens from inside without power.
- 06Enrol the users and keep the key safeOne code or fingerprint for each person, and the backup key with someone you trust.