Home Security Information Series
Type: Knowledge-base article Reading time: 5 min

Important Information

General information

This information is provided as general home security guidance only.

It is not personalised security advice, legal advice or insurance advice.

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Home Security Planning produces independent guidance using publicly available research, official guidance and practical home security principles.

Content is not sponsored by product manufacturers.

No guarantee

No security measure can eliminate the risk of burglary or other crime.

Recommendations may reduce risk but cannot guarantee prevention.

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Where crime statistics are discussed, they are drawn from publicly available official police/government data.

Home Security Planning presents and interprets that data for clarity. Reporting methods, geography and publication schedules differ between jurisdictions, and missing figures are never treated as zero.

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Local requirements

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Official guidance, standards and datasets may change; always prefer the latest official source for figures and requirements.

Why Deadlocks Matter for Home Security

External doors are among the most common burglary entry points. A deadlock is a practical, widely recommended layer of physical security — best when you understand what it does, where it helps, and what it cannot do alone.

Key recommendations

  • Fit a quality deadlock on every external door an intruder can reach — including garage-to-home doors.
  • Check glass near locks: sidelights within arm's reach can bypass a thumb turn.
  • Keep emergency exit safe — follow local fire-safety rules and keep keys accessible to occupants.
  • Combine deadlocks with lighting, visibility, and detection; locks alone are not enough.

Who should read this guide?

  • Homeowners reviewing door security
  • Renters considering security upgrades
  • People comparing lock options
  • Anyone completing a home security assessment

Supporting information

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.

Standard Latch Lock

Standard latch lock Spring-loaded latch in a door edge with a shallow strike plate Standard Latch Lock Spring latch Shallow hold · auto-retracts
  • Automatically latches closed
  • Can sometimes be bypassed more easily
  • Common on many residential doors

Deadlock

Deadlock Fixed metal bolt extending deep into the door frame Deadlock Fixed bolt key Deep throw · stays locked until turned
  • Requires key or thumb turn operation
  • Additional resistance to forced entry
  • Common recommendation for external doors
A latch keeps the door closed for everyday use; a deadlock adds a separate bolt that remains extended until you unlock it.

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:

External door entry points on a typical home Diagram of a house from above showing front, rear, side, and internal garage access doors External door entry points Garage Front door Rear door Side door Garage access Street / front of property ↓
Intruders may try any reachable external door — not only the front. Garage-to-house doors deserve the same lock consideration as main entries.
  • 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.

Glass panel adjacent to lock Door with sidelight glass within arm reach of thumb turn Glass adjacent to lock Glass Arm's reach Broken glass may allow reach-through
Lock beyond glass reach Solid door section between lock and any glass panel Lock beyond glass reach Solid Glass Deadbolt still effective if glass is distant
Deadlocks protect the bolt — not glass beside it. Sidelights or panels within reach of the lock may allow bypass unless glass is hardened or the lock cannot be turned from inside without a key (where permitted).

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.

Home security layers Stacked diagram showing deadlocks, door reinforcement, lighting, CCTV, alarm, and perimeter security as complementary layers Security works in layers Perimeter security Alarm CCTV Lighting Door reinforcement Deadlocks ↑ ↑ ↑ ↑ ↑ base No single measure prevents burglary. Security works best in layers.
Deadlocks strengthen physical entry points. They complement — but do not replace — lighting, visibility, alarms, and perimeter measures.

8. How this relates to your Home Security Planning assessment

When you complete the Home Security Planning assessment, lock type on each external door is recorded — including deadlocks, door construction, and whether glass near the lock could be reached from outside. That detail shapes your Home Security Score and where door hardware appears in your suggested action list.

FAQ

Are deadlocks worth installing?

For many homes, yes — especially where external doors rely on a latch alone. A quality deadlock adds meaningful forced-entry resistance at modest cost. Value depends on door type, frame condition, and whether glass near the lock could be reached from outside.

Should every external door have a deadlock?

Front, rear, and side entry doors are strong candidates, as are garage doors connecting to the home. Not every door needs identical hardware, but any door an intruder could target from outside deserves proper locking.

Are deadlocks safe in an emergency?

They can be when used correctly. Deadlocks secure a property when you are away or asleep — not for blocking exit while you move around the home. You should always be able to leave quickly in a fire or medical emergency. Follow manufacturer guidance and local fire-safety rules.

Can renters install deadlocks?

Sometimes, but often only with permission. Rental laws vary by country and state. You may need landlord approval before changing locks or drilling into doors and frames. Check your lease and local tenancy rules first.

Do deadlocks replace alarms or CCTV?

No. Deadlocks address physical entry resistance. Alarms and CCTV support detection, deterrence, and evidence — different layers. A balanced approach combines strong locks with lighting, visibility, and monitoring where appropriate.

Sources

This guide draws on widely published burglary prevention advice. It is not a substitute for manufacturer instructions, local building rules, or professional security advice.

  • Police residential burglary prevention and home security guidance
  • Crime prevention agency advice on deadlocks and external door locks
  • Fire and emergency services guidance on safe egress when deadlocks are fitted
  • Residential tenancy guidance on lock changes and landlord approval

Review your property in context

Review your door locks and entry points in context — the free assessment returns a Home Security Score, ordered next steps, and a PDF summary you can keep. No sign-up needed.

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Compare common security options

If you are considering this type of security upgrade, you may want to compare examples, features and installation requirements before deciding what suits your home.

Home Security Planning does not recommend specific brands, models or sellers.

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