Window locks are fittings that stop a window being opened from outside, and many also limit how far it opens from inside. For Sydney homes, the right choice depends on the window type: keyed latches suit sash and casement windows, while sliding aluminium windows need a different lock.
This guide covers the main types, which windows need which lock, safety and escape rules, and pricing. It builds on our types of door locks guide.
Key points
- Match the lock to the window type; a lock that suits a casement will not fit a sliding window.
- Keyed locks add security but must never block your escape in a fire, so keep keys close.
- Child-safety restrictors and security locks do different jobs, and many homes need both.
- Locksmith call-outs follow Sydney rates, so ask for an itemised quote and the NSW Class 2C licence number.
Window locks by window type
Start by identifying how your window opens, because that decides which lock fits.
| Window type | Common window locks | What to check |
|---|---|---|
| Sliding aluminium | Keyed latch, pin lock or sash stop | Frame thickness, whether the track is worn and whether the sash lifts out of its channel when locked |
| Casement (winder or stay) | Keyed stay lock or lockable winder | Hinge condition and stay alignment |
| Double-hung or sash | Sash lock or keyed sash fastener | Timber condition in older Sydney homes |
| Awning | Lockable stay or restrictor | Corrosion near the coast |
| Louvre | Louvre clamp or replacement with fixed glazing | Loose or missing blades |
| Bifold or stacker | Multipoint or keyed track lock | Alignment of the leaves and whether the top and bottom tracks are straight and clean |
Catches on older aluminium frames often wear loose, and a worn one can look locked while it moves freely.
Types of window locks explained
Most homes use one or more of these designs.
- Keyed locks: a key must turn before the window moves, which suits ground-floor and back windows facing a lane or fence.
- Thumb-turn latches: these hold the sash closed but offer little resistance, so treat them as a basic fix rather than real security.
- Window restrictors: a stay or cable limits the opening so ventilation continues, which also helps protect children from falls.
- Pin or bolt locks: a pin through the frame stops the sash sliding, and many installers use them as a low-cost second lock.
- Sash stops: a screw-in stop prevents a sliding window from opening beyond a set width while still allowing airflow.
- Security screens: a screen over the window adds a physical barrier, and screen doors have their own hardware; see screen door locks.
Window locks for safety, children and escape
A secure window must still be safe, and the two goals sometimes pull in opposite directions.
- Bedroom escape: keep a way out of every bedroom that opens easily from inside in an emergency, and check NCC exit and egress guidance for your home.
- Keyed locks inside: keep the key in a known spot near the window, never in a drawer in another room.
- Child safety: restrictors reduce fall risk on upper floors, and strata and rental properties often have obligations here, so ask your manager.
- Do not rely on fly screens: a screen does not stop a child falling, so fit a proper restrictor.
- Test regularly: open and close each window and lock once a season, and fix any lock that sticks, slips or feels loose in the frame.
- Get licensed advice: a Class 2C locksmith can recommend locks that balance security with safe escape for your home.
Window locks for sliding windows and doors
Sliding aluminium frames are common across Sydney and need a lock designed for their track.
- Check the factory latch: the original catch on many sliding windows is a simple hook that gives little protection on its own.
- Add a keyed second lock: fitted at the meeting stile, it stops the window lifting or sliding when the first latch is weak.
- Look at the track: worn or bent tracks let sashes lift out, which defeats any lock, so repair them first.
- Treat sliding doors the same way: they need an extra lock or bar, covered in our sliding door locks guide.
- Use one key where possible: a locksmith can key several locks alike, so you carry fewer keys.
- Check the frame fixings: a lock screwed into thin aluminium can tear out, so ask for the right fixings for your frame.
Window locks cost in Sydney
Fitting costs depend on the lock, the window type and the number of windows, and locksmith call-out prices follow these Sydney rates (October 2026, including GST).
| Job | Price range | Typical |
|---|---|---|
| Window lock supply and fitting | Quoted individually (indicative — get itemised quotes) | Varies by window and lock |
| Rekey, per lock | $52–$140 | $75 |
| Replace a single basic lock | $140–$400 | $255 |
| Deadbolt installation (nearby door) | $170–$460 | $290 |
| Extra standard key cut | $6–$34 | $14 |
- Fit several windows in one visit: grouping them avoids repeated travel charges.
- Book in business hours: after-hours, weekend and public-holiday call-outs carry a surcharge that varies by locksmith.
- Ask for matching keys: having every window lock keyed alike saves later key costs and makes it easier to open windows quickly in an emergency.
- Check door security too: windows are only half the picture, so see security door locks.
Common mistakes to avoid
- Locking every window with no escape plan: keep keys or thumb-turns reachable so anyone can leave during a fire.
- Using a cheap latch alone: thumb-turn catches slow nobody down, so pair them with a keyed lock on ground-floor windows.
- Ignoring the frame: a lock cannot hold in a rotten or flexing frame, so repair the frame as well.
- Forgetting garages and sheds: small windows there often have no lock at all; read garage and roller door locks.
- Skipping approval in rentals: tenants need written consent from the landlord or agent before fitting window locks.
Window locks FAQs
Do window locks stop break-ins?
Keyed locks make forced entry slower and noisier, which deters most opportunists. They work best with a sound frame, good fixings and secure doors. A basic thumb-turn latch alone gives little protection, so add a keyed lock to ground-floor and hidden windows.
What are the best window locks for sliding windows?
For most sliding aluminium windows, a keyed second lock at the meeting stile plus a sash stop gives good value. The right model depends on your frame, so ask a locksmith to check the track and fixings. Pricing is quoted individually (indicative — get itemised quotes).
Can I fit window locks myself?
Many are simple to fit, but the wrong fixing can damage thin aluminium or leave a gap. Renters need written consent first. A licensed locksmith can match locks to each frame, key them alike and check that bedroom escape stays safe.
Are window locks legal in a rental?
You can fit them only with the landlord or agent’s written consent, and you must give them a working key. Strata schemes may also have rules for windows on common property. Check your lease or ask the strata manager before you buy.
Next step: secure your windows with a licensed locksmith
If you are unsure which suit your frames, we can inspect each window and quote the options. TQN Locksmith’s licensed Sydney team gives you an itemised price before work starts. See the wider overview in types of door locks, then book a licensed locksmith.
