How Do I Improve the Security of My Home Locks in NZ?

Improving your home's lock security is one of the most cost-effective ways to protect your family and property. Whether you're in a draughty Wellington villa, an Auckland bungalow, or a Christchurch townhouse, the principles are the same: stronger locks, better installation, and a few smart habits go a long way. This guide walks you through what you can do yourself and when it's worth calling in a qualified locksmith.

Understand What You're Working With

Before spending money on upgrades, take stock of your existing locks. Many older NZ homes still have rim latches (the simple spring-loaded latch common on front doors) or basic deadbolts that offer minimal resistance to forced entry. Check each external door and window for:

• The lock grade — look for locks that meet or exceed AS/NZS 4145 (the Australian/New Zealand standard for locks). Quality locks will often state compliance on the packaging.
• Strike plate quality — a flimsy single-screw strike plate is one of the weakest points on any door.
• Door frame condition — a solid lock in a rotten or poorly fitted frame offers little protection.
• Key control — do you know how many copies of your keys are out there?

For independent guidance on home security standards, BRANZ publishes research and best-practice information relevant to NZ homes.

Upgrade to Quality Deadbolts

The single biggest improvement most homeowners can make is fitting a Grade 1 or Grade 2 deadbolt on every external door. A good deadbolt has a bolt throw of at least 25 mm and a hardened steel insert to resist sawing. Look for brands with AS/NZS 4145 compliance — reputable options are stocked at Bunnings and Mitre 10, or through a locksmith who can source commercial-grade hardware.

Key features to look for:

• Single or double cylinder (double cylinder requires a key from both sides — useful on doors with glass panels, but consider fire escape implications)
• Anti-pick, anti-drill, and anti-bump ratings
• Hardened steel bolt with anti-saw pins

Fitting a deadbolt is within most confident DIYers' abilities — you'll need a hole saw, chisel, and drill. However, if your door or frame needs modification, or if you're unsure about alignment, a locksmith will do the job quickly and correctly.

Reinforce Strike Plates and Door Frames

A heavy-duty strike plate secured with 75–100 mm screws that reach the wall stud (not just the door jamb) dramatically increases kick-in resistance. This is one of the cheapest and most effective upgrades you can make. Standard strike plates often come with short screws that only grip the thin jamb timber — replace these immediately.

For sliding doors and ranch sliders — common in NZ homes — fit a secondary lock or security bar in the track, and consider a key-lockable bolt to prevent lifting. Anti-lift blocks are inexpensive and easy to install.

Consider High-Security or Smart Locks

High-security cylinders (such as those with restricted keyways) mean keys cannot be copied at a regular key-cutting kiosk without authorisation. This is worth considering if you're renting out your property or have had keys go missing.

Smart locks are increasingly popular in NZ and offer features like:

• Keypad or app-based entry
• Audit trails (who entered and when)
• Temporary access codes for tradespeople or guests
• Integration with home security systems

If you're a landlord, be aware of your obligations under the Healthy Homes standards — while these focus primarily on heating, insulation, and ventilation, your general duty of care to tenants includes providing secure, functioning locks on all external doors and windows.

Don't Forget Windows and Internal Security

Locks on windows are often overlooked. Fit key-lockable sash stops or window locks to all accessible windows, particularly on ground floors. Louvre windows (common in older NZ homes) are notoriously easy to remove from outside — consider replacing them or fitting a security grille.

For a layered approach:

• Peepholes or video doorbells let you see who's at the door without opening it
• Security chains or door limiters add a secondary check
• Sensor lighting around entry points deters opportunistic burglars

Key Control and Rekeying

If you've recently moved into a new home, rekey or replace your locks as a first priority — you have no way of knowing how many keys the previous owners distributed. Rekeying (where a locksmith adjusts the lock cylinder to work with a new key) is generally more affordable than full lock replacement and is a job for a professional.

Similarly, if you've had a break-in, lost keys, or ended a tenancy, rekeying is strongly recommended.

When to Call a Professional

While many lock upgrades are DIY-friendly, call a qualified locksmith when:

• You need to rekey or replace locks after a break-in or lost keys
• You're installing a high-security or smart lock system
• Your door frame or door itself needs repair or reinforcement
• You're locked out of your home
• You want a full security audit of your property

Lock installation and security work is not restricted work under NZ law (unlike electrical or plumbing), so there's no licensing requirement for locksmiths — but experience and reputation matter. Look for a locksmith who is a member of the Master Locksmiths Association of Australasia (MLAA) or who comes with strong local reviews. You can find trusted local locksmiths on tradedirectory.co.nz.

A Quick Comparison: Lock Types

Sources & Further Reading

• BRANZ – Building Research
• Standards NZ – AS/NZS 4145 Lock Standards
• MBIE Building Performance – NZ Building Code
• Tenancy Services – Healthy Homes
• Bunnings – Door Security Hardware
• Mitre 10 – Locks & Security