Domakihub Install a Window Security Lock and Stop Break-ins
The right window lock is your first line of defence against the most common burglar entry point.
Reviewed by Domakihub home & decor pros · 2026-06-23 · 5 min read
Windows are the most frequently exploited entry point in residential break-ins across Greece, yet many apartment owners and holiday villa managers leave them secured by nothing more than a basic latch. The video above walks through a practical installation on a standard casement window, and this guide expands on those steps with advice tailored to the window types and property situations most common in Greek homes, rental villas, and boutique hotels. Whether you manage a single Athens flat or a portfolio of island properties, fitting a quality window lock takes under an hour and significantly raises the effort required for a would-be intruder.
Why Windows Are the Weakest Link in Most Greek Properties
Standard Greek apartment windows — particularly older aluminium sliding frames and single-glazed casements — are often fitted with manufacturer latches that were never designed to resist forced entry. A burglar can defeat a worn or poorly aligned latch in seconds using a simple screwdriver or credit card. Ground-floor windows and those accessible from a balcony or flat roof are especially high risk, which describes a large proportion of the holiday villa and apartment stock in popular tourist destinations.
Insurance assessors and local crime statistics consistently flag unsecured windows as a factor in opportunistic break-ins. Unlike a reinforced door, a window lock is an inexpensive, reversible upgrade that tenants, guests, and property managers can install without structural work — making it one of the highest-value security improvements available per euro spent.
Choosing the Right Lock for Your Window Type
The three window configurations you will encounter most often in Greek properties are sliding aluminium windows (common in post-1980 apartment blocks), outward-opening casement windows (typical in older village houses and island villas), and sash windows (rarer but found in neoclassical buildings in Athens and Thessaloniki). Each type demands a different locking mechanism. Sliding windows benefit from a key-operated bolt or a charlie bar that drops into the track to prevent the panel from moving. Casement windows pair well with a surface-mounted lockable handle or a wedge lock that clamps the frame. Sash windows are best secured with a dual-screw sash lock or a window stop that limits travel to a ventilation gap.
For holiday rentals and hotels, choose locks that guests can operate easily from inside without a key for fire-safety compliance, while still providing meaningful resistance from outside. Keyed locks make sense for unoccupied periods; thumb-turn or push-button variants work better when guests are in residence. Whichever you choose, pick a model with a solid steel bolt or bar rather than a zinc-alloy cam — the difference in forced-entry resistance is substantial.
How to Fit a Window Security Lock in 5 Steps
- 1
Gather your tools and choose your lock
Before you start, identify your window type and buy the appropriate lock — a keyed bolt for sliding aluminium frames, a lockable casement handle or wedge lock for outward-opening windows, or a dual-screw sash lock for sash windows. You will need a pencil, a tape measure, a cordless drill with the correct bit for your frame material (use a 3 mm pilot bit for aluminium), and a screwdriver. Lay everything out so you are not hunting for tools mid-installation.
- 2
Clean and inspect the frame
Wipe the mounting area with a dry cloth to remove dust, paint flakes, and any old adhesive. Open and close the window fully to check for warping, cracked seals, or misalignment — a distorted frame can prevent a lock from seating properly. If the frame is bowed or the existing latch no longer catches cleanly, realign or replace the latch strike plate before adding a secondary lock, otherwise the new hardware will be working against a flawed base.
- 3
Mark and drill pilot holes
Hold the lock body against the frame in the position specified by the manufacturer — typically 150–200 mm from the corner of the frame on a sliding window, or centred on the meeting rail of a casement. Mark the screw holes with a pencil. Drill shallow pilot holes (no deeper than two-thirds the screw length) to avoid cracking aluminium or splitting timber frames. For uPVC frames, use self-tapping screws and apply steady, even pressure rather than forcing the drill.
- 4
Mount the lock body and strike plate
Secure the lock body with the supplied screws, tightening until snug but not over-torqued — stripped holes in aluminium are difficult to repair. Close the window and use the lock body as a template to mark the position of the strike plate or bolt receiver on the opposing frame. Open the window again, drill the strike plate holes, and fix it in place. Test that the bolt or bar engages smoothly; file the strike plate opening by a fraction if the bolt drags.
- 5
Test, adjust, and document for guests or tenants
Lock and unlock the window at least five times from both sides to confirm smooth operation. Check that the window cannot be slid or pushed open beyond the lock's travel limit. For holiday rentals, photograph the installed lock and include brief written instructions in your guest welcome pack — guests who understand how to use a lock will actually use it. If you have installed keyed locks, keep one spare key labelled and stored securely off-site or in a managed key box.
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FAQ
- Will drilling into my aluminium window frame void the manufacturer warranty?
- For most residential aluminium frames in Greece, the original manufacturer warranty will have lapsed well before most owners consider adding secondary locks. If your windows are recently installed and still under warranty, check the warranty document or contact the supplier before drilling — some manufacturers offer clip-on or adhesive-mount lock options that do not require drilling and preserve the warranty.
- Can I fit a window lock that still allows ventilation overnight?
- Yes. Window restrictors and ventilation stays are designed specifically for this purpose. They allow the window to open 100–150 mm for airflow but prevent it from opening wide enough for a person to enter. These are particularly useful for bedrooms in holiday rentals where guests want fresh air at night without compromising security. Choose a model with a push-release override that allows full egress in an emergency.
- How many locks does a single window actually need?
- For most standard-size windows, one quality lock positioned at the centre of the opening sash is sufficient. Larger windows — over 1.2 metres wide — benefit from two locks placed at quarter points along the frame to prevent the frame from being flexed open in the middle. Ground-floor windows and those accessible from a communal balcony or terrace are higher risk and warrant two locks regardless of size.