A door lock is a security device, but it is also something you use several times a day. A lock that jams, a digital lock that drains batteries because the bolt is misaligned, or a handle that works loose — these are daily irritations that often indicate an installation problem rather than a faulty product.

In Singapore, homeowners increasingly choose digital locks for the convenience of keyless entry, especially for rental units and homes with children or elderly parents. But digital locks are not automatically better, and not every door is suitable. This guide compares digital and mortise locks and explains what determines a successful installation.

Digital Locks: Convenience and Trade-Offs

A digital lock replaces the mechanical key with a keypad, fingerprint reader, card reader or smartphone app. Most models retain a mechanical key override for emergency access.

Advantages:

• No need to carry or hide a key.
• Access can be granted temporarily to contractors, cleaners or guests.
• Some models log entries and exits, useful for rental units.
• Convenient for elderly family members who may struggle with keys.

Considerations:

• Requires batteries; a failing battery without warning can lock you out if the override is not accessible.
• Electronic components are sensitive to moisture and impact.
• Installation is less forgiving — the lock body must align precisely with the door and frame.
• Higher upfront cost than a mechanical lock.
• Cybersecurity matters for app-connected models; default passwords must be changed.

Mortise Locks: Proven and Repairable

A mortise lock sits inside a pocket cut into the door edge. It is the standard lock in most Singapore homes and remains the most common choice for good reason.

Advantages:

• Mechanical, with no batteries or electronics to fail.
• Robust and well understood by locksmiths and handymen.
• Easy to repair or replace individual components.
• Lower cost.

Considerations:

• Requires carrying a key.
• Key management becomes an issue for rental units.
• Lock changes are needed when tenants change, unless a restricted-key system is used.

Does Your Door Suit a Digital Lock?

Not every door does. Key factors include:

• Door thickness. Digital locks have a specified thickness range. Too thin and the lock body will not fit; too thick and the spindle may not engage correctly.
• Existing bore holes. Many digital locks require specific hole positions. An existing mortise cut-out may or may not be adaptable.
• Door material and condition. Hollow-core doors may need reinforcement. A door that is already splitting at the lock area is a poor candidate.
• Frame condition. The strike plate must align with the bolt. A shifted or damaged frame will prevent any lock from working reliably.
• Shelter and exposure. A lock on an exposed gate or door receives rain and sun. Not all digital locks are rated for outdoor use.

A reputable installer will check these before drilling. If a particular model will not fit well, it is better to advise a different model than to force the installation.

Why Alignment Matters More Than the Lock

Most lock problems are alignment problems. If the door has dropped on its hinges, swollen from moisture, or the frame has shifted, the bolt will not seat cleanly in the strike plate. The lock then needs force to close, the motor works harder, batteries drain faster, and eventually something fails.

This is why a professional installation starts with the door, not the lock. Hinges are checked and tightened, the door is adjusted if it is scraping or sagging, and the strike plate is positioned so the bolt engages fully. Only then is the lock fitted.

Installation Costs in Singapore

Labour for a straightforward mortise lock or knob replacement is typically modest and can often be completed within an hour. Digital lock installation with setup generally takes 1 to 2 hours, longer if the door requires adjustment or new holes. If you supply your own lock, expect a fixed labour rate; if the installer supplies it, the lock cost is added. Always confirm whether old lock removal and disposal are included.

Common Installation Mistakes

• Drilling the door before checking the lock's required hole positions and door thickness.
• Fitting a digital lock to a door that is already misaligned, so the bolt drags.
• Using short screws that do not reach the door's reinforcing material.
• Leaving the mechanical key override inaccessible or untested.
• Not changing the default master password on an app-connected lock.
• Ignoring weather exposure on an outdoor gate.

Frequently Asked Questions

Can a digital lock be installed on an existing HDB door?

Usually yes, provided the door thickness and existing holes are suitable or can be adapted. The door and frame should be checked first.

What happens if a digital lock's battery dies?

Most models give a low-battery warning and retain a mechanical key override or emergency power terminal. Test the override at installation and keep the key accessible outside the home.

Why does my door not close properly after a new lock was fitted?

Most commonly the lock or strike plate is misaligned, or the door has moved since installation. A lock cannot compensate for a door that no longer sits square in its frame.

Can you repair a split door frame?

In many cases yes — split frames can be repaired and stripped fixing points rebuilt. If the damage is severe, a reliable long-term repair may not be possible, and this will be explained before work begins.

For door lock installation, digital lock fitting and door alignment in Singapore, contact AIM Global Engineering PTE LTD at +65 9081 8494. We check the door before the lock. BCA and ACRA registered (UEN 202211612M).