Types of Window Locks

Types of Window Locks

Whether you’re choosing new locks for an existing window or deciding on locks for your replacement windows it’s good to have an idea of what options you may encounter. Generally, the options depend on the window’s style of operation, window locks also vary aesthetically. Read on for an overview of standard residential window locks. 

Standard Locks For Your Home’s Windows

Lock options vary by window vendor but generally, in the United States, you’ll see locks like those listed below. There are many other options available including “smart locks” that work with your security system. 

Locks for Hung Windows 

Single-hung and double-hung windows typically have auto-lock or sash latch hardware. The material available for the window and the profile depends on the manufacturer’s design. In the examples below are locking hardware options from Milgard’s Essence Series. Milgard offers a SmartTouch® lock (auto-lock) and a Spoon lock (sash latch).

Locks for Milgard Essence Double-Hung Window. SmartTouch® (Top) & Spoon Lock (Bottom). Image Credit: Milgard

Locks for Sliding Windows

Sliding windows are very similar to hung windows except they operate horizontally instead of vertically. Window companies generally use the same types of locks for hung and sliding windows. The image below is from Milgard’s Essence Horizontal Slider Window, as you can see it’s the same options as are available for the double-hung window except in a different finish. 

Locks for Milgard Essence Horizontal Slider Window. SmartTouch® (Top) & Spoon Lock (Bottom). Image Credit: Milgard

Locks for Casement Windows

Casement windows have locks and sometimes they have swivel operators. Swivel operators push and pull the hinged sash into an open and closed position. When the window is closed it can be locked into place with the handle lock located on the side of the window. The lock on casement windows provides a tight seal. 

Locks for Awning Windows

Like casement windows, awning windows have an operator and a sash lock. Awning windows actually have two locks, one on either side of the window because they are hinged along the top instead of the side. 

Picture Windows Don’t Have Locks

As a reminder, picture windows are stationary and because of that, they don’t open. While this allows for more energy efficiency and glass space that maximizes the view, that also means these windows do not need any locks on them. 

Can Locks Be Changed Aftermarket?

There are plenty of locks that are installed aftermarket. These locks help boost window security and keep your home safe. The most common reason for locks being changed aftermarket is so that lock can serve as a secondary source of security; locks can be changed with a complete switch aftermarket, but you need to do your research to make sure the replacement lock is a good fit for your window type. Also, consider whether the aftermarket lock will void any existing warranties on your window. 

ANSI Lock Ratings

Much like other window parts, the different lock types also differ in their quality. The American National Standards Institute has a specific grading system they use to figure out how strong your locks are. They are: 

Grade 1 – The highest grade of ANSI’s lock ratings, Grade 1 considered the safest locks that offer the most security. Of course, the flip side to this is that along with the most security is the fact that these locks are also the most expensive. 

Grade 2 – This middle level, Grade 2 locks offer a more standard level of security and are much more commonly used by homeowners. 

Grade 3 – The cheapest option for window locks, Grade 3 locks are the simplest locks available and are more commonly used in combination with a more secure lock. 

How Much Do Aftermarket Window Locks Cost?

Depending on the window type and the lock that it requires, window locks can be relatively inexpensive, ranging anywhere from $5-$30 per lock. Of course, the more locks you need the more you’ll pay, so it’s easier to purchase higher-quality locks if you don’t have as many to buy. Window locks are also usually self-installed, so your purchases run the risk of choosing an incorrect lock or not installing it properly. 

Additional Security Measures

Some homeowners appreciate additional security measures. Below are three options available at your local home improvement store. We recommend working with the vendor of your window to see what options they have before shopping elsewhere especially if your window comes with a warranty. Making changes to windows can sometimes void any existing warranties. 

  • Keyed Locks
  • Sliding Window Locks
  • Dowels

Keyed locks

Often used in combination with window latches, keyed locks are typically locks that are found on the side of a window and require a key to unlock. Though it’s more commonly used on hung windows, these locks can also appear on sliding windows as well. 

Sliding Window Locks

Typically used with a level or thumbscrew, sliding window locks are placed in the track of a sliding window to prevent it from opening. There is a potential for this lock to have a key for added security, but it’s not necessary for use. 


A very simple way to lock a sliding window is by putting a dowel that is made to fit between the sliding window and the jamb of the window by laying it in the track of the window for security. This is a good suggestion for windows that are only open periodically. 

There is more to selecting window locks than meets the eye, and it starts with knowing the types of window locks and where they fit in your home. With proper research and consultation, choosing window locks should be one of the easier upgrades you make to your home. Still, please be sure to talk to a professional before your purchase to ensure you’re making the best decision for your windows. 


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