Why Deadlocks Matter for Home Security

1. What is a deadlock?

A deadlock (often called a deadbolt) throws a solid metal bolt into the door frame when you turn the key or thumb turn. Unlike a spring-loaded latch on a handle, the bolt stays extended until you unlock it — it does not retract when pressure is released.

That fixed bolt is what makes a deadlock effective against many forced-entry attempts. The lock is "dead" until operated — hence the name.

2. Deadlocks vs standard latch locks

Most external doors have a latch in the handle set. When you close the door, the latch snaps into a strike plate — convenient, but offering limited resistance. Latches can often be slipped, manipulated, or forced, especially on older or poorly fitted doors.

A deadlock adds a separate, deeper bolt — typically 25 mm or more into the frame — that is not spring-loaded. A latch keeps the door closed in daily use; a deadlock secures it when you leave or at night.

3. Why deadlocks matter for burglary prevention

Burglaries are often opportunistic. Offenders choose targets that look quick and quiet to enter. Police guidance consistently highlights inadequate door locks as a factor in many residential break-ins.

A properly installed deadlock increases the time, noise, and effort to force a door. It does not make a home invulnerable — but it can deter an opportunist, cause abandonment of the attempt, or delay entry long enough for someone to notice.

4. Which doors should be considered?

Consider every door an intruder could reach from outside without passing another secured barrier:

• Front door — often targeted when other routes look harder.
• Rear and side doors — frequently less visible and sometimes weaker or older.
• Garage entry doors — treat the garage-to-home door like a main entry.
• Patio and external glass doors — may need deadlocks or multi-point locking; glass and frame type also matter.

5. Deadlocks and glass panels near doors

A deadlock protects the lock side, not glass beside it. Large panels, sidelights, or inserts within arm's reach let an offender break glass and reach inside to turn a thumb turn or handle — bypassing the bolt.

Consider keyed double-cylinder deadlocks (where local rules allow), security mesh or laminated glass on vulnerable panels, or relocating thumb turns away from glass reach. Always balance security with safe exit in an emergency.

6. Safety and emergency exit considerations

Security must not block safe escape. Building codes and fire-safety rules in many countries restrict how doors can be locked from the inside — particularly keyed locks on exit routes.

• Do not deadlock yourself inside without a secondary exit you can use quickly.
• Keep keys accessible to occupants — not visible through letterboxes or glass.
• Follow local regulations for rental properties, apartments, and shared buildings.
• Renters should check with landlords before changing locks.

7. Deadlocks are only one layer

Even the best deadlock does not stop every break-in. Windows, sliding doors, weak frames, poor lighting, and concealed rear access all matter. Alarms and CCTV deter and detect — but they do not physically stop entry if the door itself is weak.

8. How this relates to your Home Security Planning assessment

The free Home Security Planning assessment asks about lock types on each external door — whether a deadlock is fitted, door construction, and whether glass near the lock could be reached from outside. Those answers feed your Home Security Score and prioritised recommendations.

9. Frequently asked questions