Window Lock Guide

Windows are easy entry points for intruders if you do not know how to secure them properly. In this guide, you’ll learn everything you need to know about locking your windows.


It’s no secret that doors and windows are the most accessible and easy points of entry for burglary. In our experience, securing your points of entry is one of the most critical measures you can take to protect your home and family from burglars and thieves. That’s why it’s extremely important to make sure your doors and windows are safely secured and firmly in place.

Installing Vivint Window Sensor

Installing the Vivint Window Sensor

If you want to prevent theft, you should always close your blinds or block visibility into your windows. Burglars will use any information they can gather to determine whether or not your house is a good target. If they can see into your house, they can not only identify items worth stealing, but they might also learn about the layout of your home and the behaviors, habits, and patterns of your family.

Pro Tip: Don’t give criminals even one inch to work with — they will always take a mile.

In addition to covering your windows, you should also keep them locked and unavailable for entry. That said, even though windows are a prime access point, they are typically not the first point of entry that a burglar will attempt. Most of the time, an intruder will try to enter through an unlocked door. So we recommend always checking your doors and windows to make sure they are locked. To learn about the burglars’ mindset, check out our tips and tricks to keep burglars from breaking-in.

Are All Window Locks Safe?

Unfortunately, the truth is that all window locks are not safe. We’ve seen a lot of windows with cheap or weak locks that simply keep the window closed to ensure the home’s energy efficiency. In older homes, you may find window locks that are actually designed for a different type of window. There are, however, some windows that have adequate locks and hardware.

Cheap window locks are also a bad idea. The adage “You get what you pay for” applies here. Cheap window locks are often made of cheap aluminum or plated copper and are easy to bend or break. It’s always best to spend a little bit extra on sturdier hardware that you know will stand up to the task.

Types of Windows

When you decide that it is time to replace or update the locks on your windows, you’ll want to first determine what types of windows you have so you can buy the right type of locks. This might seem obvious, but like we said, we’ve seen plenty of mismatched windows and locks, making the window more vulnerable to break-ins. Here’s a quick look at a few different styles of windows.

Sliding Windows

Sliding windows are easy to use and quite simple to open and close. That being said, they need to be securely locked to keep the house safe. Most sliding windows use a lever or a thumbscrew to engage or disengage their locking mechanism. Also, note that sliding windows are the norm in most modern neighborhoods and homes.

Casement Windows

Casement windows stand apart from other windows because they are opened and closed with a crank. You’ll find these in many older homes. Casement windows can be adjusted so that the crank can only be opened to a certain point. This rigid, manual means of opening and closing make casement windows one of the safer styles of windows. They can have various styles of locks installed or built into them.

FYI: To ensure that a casement window doesn’t become a fire hazard, the crank mechanism must be set properly so that the biggest person in your family can climb out of the window should a fire break out in your home.

Double-Hung Windows

Double-hung windows are one of the most common styles of windows found in houses on the market today. They are opened from the bottom and slid upwards. Some styles can also be opened from the top. Older double-hung windows often lack adequate locks, however. Modern locks and/or latches should be installed on your double-hung windows to make them less prone to break-ins.

Types of Locks for Your Windows

Each style of window will have a specific style of lock that will work best. It’s worth repeating that you should always take care to find and install the right locks or latches onto the specific styles of windows in your home. Here is a list of the different styles of locks that you will need to choose from.

Sash Locks

Sash locks are commonly intended for use on double-hung windows. They are made up of two pieces. There is a crescent-shaped piece that turns to enter or exit a housing piece that looks similar. Since they are made of metal and there is a relatively large area of contact for the two pieces of the latch, these are fairly safe and work great to secure your double-hung windows.

Keyed Locks

Keyed locks can be installed onto multiple styles of window. They are an extremely secure option and require a key to unlock them. They are usually installed onto the bottom of the window and secured to the frame. Keyed locks are an excellent deterrent as they are very difficult to break in through.

Window Bars

Window bars are extremely effective. Even if the glass is broken, an intruder will still have a hard time removing the bars to fit through the window itself. However, window bars should always be installed by a professional. If they are installed incorrectly, they could possibly damage the exterior wall or be ineffective to keep burglars out.

One of the downsides to window bars is that they can actually decrease the value of your home. People often assume that the presence of window bars means that the neighborhood is unsafe.

Did You Know: Another reason why it’s vitally important to have a professional install your window bars is that, in some cases, they may become a fire hazard if they don’t open from the inside when seconds matter most.

Window Latches

Window latches are probably the most aesthetically pleasing option when it comes to securing your windows. Vinyl windows often use a latch that looks and operates much like a window sash. Casement windows, however, often utilize a folding window latch. The folding latch is simply folded down to lock the window.

SimpliSafe - Equipment

SimpliSafe – Equipment

Home Security Systems

Although not technically a lock, a home security system with window entry sensors can be another layer of protection for your windows. They work by sounding an alarm and alerting the owner when the system senses that a window has been opened. This is most commonly accomplished with magnetic contact sensors. The sensors remain close together, nearly touching, while the window is closed. And when the window is opened, the magnetic sensors break contact and the alarm is tripped. If you want to learn more and find a system that works for you, check out our list of the best home security systems available.

Why Are Window Locks So Important?

Window locks are important because windows can be an easy way for a burglar to enter your home. After realizing that your door is locked, most burglars will head straight for the windows. And let’s be honest, even for inexperienced burglars, entering an unlocked or poorly locked window can take mere seconds. However, a locked window can take quite some time to open from the outside, if it can be opened at all.

Why Would a Burglar Not Just Break the Window?

A lot of people wonder about this. The answer is quite simple. Breaking a well-constructed window is surprisingly hard work. If the burglar succeeds in breaking the window, he or she will probably sustain some pretty serious lacerations from the sharp glass. The biggest reason that a smart burglar will not break a window (especially a large one) is that the noise from a broken window will surely alert the neighbors. However, it’s important to remember that smash and grabs still happen!

Vivint Glass Break Sensor

Vivint Glass Break Sensor

Pro Tip: When purchasing a home security system, look for glass-break sensors. These little sensors are mounted near windows and are capable of detecting the high-frequency noise of shattering glass and sounding the siren. We’ve found that Vivint has one of the best glass-break sensors on the market. You can read our in-depth Vivint review here.

Don our Vivint Installation Technician, Installing the Vivint Glass Break Sensor

Don, our Vivint Installation Technician, Installing the Vivint Glass Break Sensor

Fire Escapes

Something to keep in mind while protecting your home is the placement of a fire escape ladder. Some people leave their fire escape ladders hanging from their windows. This is an invitation for burglary. Not only can a fire escape ladder be used to reach an upper-level window, but it can also be used to pry open a window or a door. So while it’s critically important to have a fire escape ladder, just be sure to keep it rolled up and put away while you are not home. For more information on fire safety, have a look at our Residential Fire Prevention and Safety Guide. It could save a life!

Final Words on Windows

We hope this window lock guide has helped you to grasp the importance of windows and window locks and how they work. Remember, when you are replacing your window locks, pay close attention to the type of windows that you have and which locks will work the best for your style of windows. Keep a light on and your curtains drawn while you are away so that your house does not appear vacant and so that would-be burglars cannot see inside your windows.

You should always take maximum precautions when it comes to protecting your home. Your windows and doors should be secured and you should possibly consider getting a home security system that has window entry sensors if you do not have one already. They are a great extra layer of security for your home and often come with plenty of great features.