Digital lock installation in Singapore: door types, fit & what to check
A digital lock is one of the best small upgrades for an HDB or condo — no more fumbling for keys. But not every lock fits every door. Here's what to check before buying, and what a proper installation involves.
Royston Chan5 min readDigital locks have gone from luxury to standard on Singapore front doors — keyless entry, PIN codes, fingerprint, and app access for when the helper or your in-laws arrive. It's one of the most popular jobs our digital lock installation service handles. But the most common mistake is buying the lock before checking it fits the door. Here's the order to do it in.
Check the door first
- Door thickness: most digital locks fit a range (often ~38–55mm). Measure yours before buying.
- Material: HDB fire-rated main doors, timber doors and metal gates all mount differently. Tell the installer what you have.
- Existing lock type: the new lock usually replaces the existing mortise; the cut-out may need adjusting.
Mortise vs rim locks
Two broad types: mortise locks fit into a slot cut into the door edge (cleaner, stronger, the common choice for main doors), and rim locks mount on the surface of the inside face (often used on metal gates). Which one suits depends on your door — a good installer will tell you on sight, the same way they would when mounting a TV on the wall and reading what's behind the surface before drilling.
| Feature | Mortise lock | Rim lock |
|---|---|---|
| How it mounts | Fits into a slot cut into the door edge | Mounts on the surface of the inside face |
| Typical use | Main doors | Metal gates |
| Strengths | Cleaner, stronger | Simpler to mount on a gate |
HDB fire-door rules
HDB main doors are fire-rated, and there are rules about modifying them. A proper installation works within those — the right lock, mounted correctly, without compromising the door's integrity. This is a big reason to use someone who installs these regularly rather than a generic handyman, and it's the same care you want for any HDB main-door job like fitting a curtain rail near a fire-rated wall.
What a clean install involves
- Removing the old lock and checking the cut-out alignment.
- Adjusting the mortise pocket and drilling for the spindle/cables to the exact template.
- Mounting the front and back panels flush, aligned and not over-tightened.
- Fitting batteries, pairing the app, and registering PINs/fingerprints.
- Testing auto-lock, manual override and the mechanical key backup.
The takeaway
Measure the door thickness and know your door type before you buy, and use an installer familiar with HDB fire doors. If you're kitting out a new flat, it's worth booking the lock alongside other small jobs like furniture assembly on the same visit, and reading our guide to TV wall mounting in Singapore if that's on your list too. Bought a lock already, or want a recommendation that fits your door? Our handyman team installs digital locks on HDB and condo doors — WhatsApp us a photo of your door and the lock model and we'll confirm the fit.
Frequently asked questions
- Can you install a digital lock on an HDB fire-rated main door?
- Yes. HDB main doors are fire-rated and there are rules about modifying them, so a proper installation works within those — the right lock, mounted correctly, without compromising the door's integrity. This is why it's best to use an installer who fits these regularly rather than a generic handyman.
- What door thickness do digital locks fit?
- Most digital locks fit a range, often around 38 to 55mm, but it varies by model. Measure your door's thickness before buying so you know the lock will fit. Also note your door material — fire-rated main doors, timber doors and metal gates all mount differently.
- What's the difference between a mortise and a rim digital lock?
- A mortise lock fits into a slot cut into the door edge — cleaner, stronger, and the common choice for main doors. A rim lock mounts on the surface of the inside face and is often used on metal gates. Which one suits depends on your door, and a good installer can tell on sight.
- What does a proper digital lock installation involve?
- Removing the old lock, checking the cut-out alignment, adjusting the mortise pocket and drilling to the template, mounting the front and back panels flush and not over-tightened, fitting batteries, pairing the app, registering PINs and fingerprints, then testing auto-lock, manual override and the mechanical key backup.
- Should I buy the digital lock before or after checking my door?
- Check the door first. The most common mistake is buying the lock before confirming it fits. Measure the door thickness, know your door type and material, and note the existing lock, since the new lock usually replaces the existing mortise and the cut-out may need adjusting.