Window Locks: Sash Locks, Child Safety and Egress

We may earn commission from links on this page. Lead-form submissions are forwarded to local inspector partners. How we research and review.

Window locks are easy to overlook. A small cam latch at the meeting rail of a double-hung window, a lever on a casement crank or a pin through a sliding sash rarely gets a second glance until it breaks, refuses to close or lets a window drift open. Yet the hardware on a window sits at the intersection of three different concerns: keeping intruders out, keeping young children from falling out, and making sure everyone inside can get out quickly in a fire. Those goals can pull in opposite directions, and the right setup depends on the room, the window type and who lives in the house. This guide explains common window locks and latches, how window stops and limiters work, what CPSC guidance says about child window falls, why emergency escape windows must stay easy to open, how older sashes affect locking, what inspectors check and what upgrades typically cost.

Part of our Structure & Exterior guide — start there for the full picture →

What Window Locks Actually Do

Most residential window locks are better described as latches. Their first job is to pull the sash tight against the frame and weatherstripping so the window seals against drafts, dust and noise. Their second job is to resist someone opening the window from outside. Very few standard window latches are designed to stop a determined intruder who is willing to break glass, but a latched window does resist casual prying and makes a quiet entry harder.

That dual purpose is why a window that will not latch is worth fixing even in a home where security is not a worry. An unlatched double-hung window often leaks air at the meeting rail, rattles in wind and lets the upper sash slide down over time. On the Front Range, where winter chinook winds and summer storms push hard on windows, a sash that is not pulled tight can whistle and leak noticeably.

Common types of window locks

• Cam or sash locks. The rotating latch mounted on the meeting rail of double-hung and single-hung windows. Turning the lever hooks a cam into a keeper on the other sash and draws the two rails together.
• Casement and awning locks. Lever-style locks, sometimes multi-point, that pull a crank-out sash tight against the frame. Larger casements may have locks at two or more points along the sash.
• Sliding window latches. Hook or thumb latches on horizontal sliders, often supplemented by a bar in the track or a pin through the frame.
• Keyed sash locks. Latches that need a key to open. These add security but raise escape concerns in bedrooms, discussed below.
• Pin or bolt locks. A pin drilled through both sashes of a double-hung window, or through a slider frame, that prevents movement until removed.
• Window stops and limiters. Devices that let a window open only a set distance, intended mainly for child safety and ventilation.

Window Locks and Child Fall Prevention

Window falls are one of the clearest cases where window hardware is a safety device rather than a convenience. In a 2026 release for National Window Safety Week, the U.S. Consumer Product Safety Commission reported that an estimated 5,600 children aged 12 and under were treated in emergency departments in 2024 after falling out of a window, and that about one in three of those cases required hospitalization. CPSC also said it was aware of at least 25 deaths among children 12 and under from window falls between 2021 and 2023, with 80 percent of those fatalities occurring between May and October.

The timing matters. Front Range households tend to open windows widely from late spring through early fall to take advantage of cool evenings, which is exactly when CPSC data shows the most fatal falls.

CPSC recommendations

CPSC’s window safety guidance includes these steps, which appear in both its “Preventing Window Falls” handout and the 2026 release:

• Install window guards to prevent children from falling out of windows. For windows on the 6th floor and below, use guards that adults and older children can open easily in case of fire.
• Install window stops so that windows open no more than 4 inches.
• Never depend on screens to keep children from falling out of windows.
• Whenever possible, open windows from the top rather than the bottom.
• Keep furniture away from windows to discourage children from climbing near them.

The point about screens deserves emphasis. A screen is designed to keep insects out, not to hold the weight of a leaning child, and many window falls involve a child pushing through a screen. A standard sash lock also does nothing once the window is open; it only matters when the window is closed and latched.

Window stops versus window guards

Window stops, sometimes sold as opening control devices or limiters, mount on the sash or frame and block the window from opening beyond a set distance, typically about 4 inches in line with the CPSC recommendation. Many have a release that an adult can operate so the window can open fully when needed. Window guards are bars or grilles installed across the lower part of the opening. Our guide to window guards covers types, spacing and the importance of quick-release mechanisms on any window that may be needed for escape.

For many single-family homes, stops on upper-floor windows plus a habit of opening double-hung windows from the top are a practical combination. Parents should check that any device they buy can be released quickly by an adult without tools, especially in bedrooms.

Egress Windows Must Open Without Keys or Tools

Bedrooms and some basement living spaces need an emergency escape and rescue opening, usually a window, so occupants can get out and firefighters can get in. Residential building codes commonly require that these openings be operable from the inside without keys, tools or special knowledge. Requirements vary by code edition and local amendments, so confirm with the building department in your city or county, whether that is Denver, Aurora, Colorado Springs or a smaller Front Range jurisdiction.

That rule has practical consequences for window locks:

• Keyed sash locks on bedroom egress windows can defeat the purpose of the window if the key is not immediately at hand during a fire.
• Pin locks and track bars must be easy to remove in the dark and in a hurry; a pin that requires a screwdriver or a bar that is wedged tight is a problem.
• Window stops and guards on escape windows should have a release that an adult or older child can operate quickly.
• Painted-shut or nailed sashes, common in older homes, effectively remove the escape route.
• Security bars on basement windows need inside quick-release hardware if the room is used for sleeping.

The U.S. Fire Administration’s home fire escape planning guidance tells households to draw a map of the home that includes all doors and windows, find two ways out of every room, and make sure doors and windows are not blocked. It also notes that residents could have less than 2 minutes to escape a home fire once the smoke alarm sounds. A bedroom window that is locked with a missing key, painted shut or blocked by a stop that no one knows how to release may not be a usable second way out.

Basement bedrooms are a frequent issue in Front Range resales, where finished basements are common and the original windows may be small. If a basement window is too small or too high to serve as an escape route, adding a properly sized opening with a window well is the usual fix. Our guide to egress window installation cost explains sizing, window wells and typical budgets.

Balancing Security and Safety

The goal is a window that latches firmly against intruders, limits how far it opens when children are present, and still opens fully and quickly when someone needs to get out. A few approaches help reconcile those goals:

• Use sturdy, non-keyed latches on bedroom windows and rely on stops with adult-operable releases rather than keyed locks.
• Reserve keyed locks for windows that are not escape routes, such as some ground-floor windows in non-sleeping rooms, and keep keys near the window if used at all.
• Consider laminated or security film on glass that faces vulnerable areas, since many break-ins involve broken glass rather than a defeated latch.
• Add exterior lighting and trim landscaping near ground-floor windows so they are visible from the street.
• Practice opening every escape window, including releasing any stops or guards, as part of a household fire drill.

Window sensors on an alarm system add another layer without making windows harder to open from inside.

Old Sashes, Worn Hardware and Locks That Won’t Latch

A window lock can only work if the two parts line up. In older homes, latches often fail for reasons that have nothing to do with the lock itself:

• Sashes out of alignment. Settlement, worn balances or swollen wood can leave the meeting rails offset so the cam misses its keeper.
• Worn balances or broken cords. A sash that will not stay up, or that slides down on its own, leaves a gap at the meeting rail that the latch cannot close.
• Paint buildup. Layers of paint can lock sashes in place or prevent the latch from turning fully.
• Stripped screws. Latch screws in soft or decayed wood pull out, so the lock spins or lifts away under pressure.
• Brittle vinyl or broken plastic parts. Some older vinyl windows use plastic latches and keepers that crack with age and sun exposure, a common issue at Colorado’s high elevation and strong UV.

Sometimes replacing the latch is enough. In other cases the sash itself needs repair, new balances or replacement. Our guide to double-hung windows explains how balances, sashes and meeting rails work, and our guide to window sash replacement covers when a new sash or sash kit makes sense compared with replacing the whole window.

Routine maintenance for window locks

Window hardware lasts longer with a little attention once or twice a year. Clean dust and grit out of sash tracks and slider channels, since debris makes sashes stick and puts strain on latches. A dry lubricant or a product recommended by the window manufacturer on moving latch parts and tracks keeps them operating smoothly; oily products can attract dust. Tighten loose latch and keeper screws, and if a screw spins in its hole, a longer screw or a filled and re-drilled hole may hold better. Check that weatherstripping is intact, because a compressed or torn seal can keep a latch from reaching its keeper. Spring and fall, when windows are opened and closed for the season, are convenient times to run through every window in the house.

Lead paint caution on older windows

Windows in homes built before 1978 may have lead-based paint on sashes, sills and stops, and friction surfaces like window channels can generate paint dust. Scraping paint to free a stuck sash or sanding around a latch in an older home is work that calls for lead-safe practices. EPA’s Renovation, Repair and Painting Rule requires that anyone paid to perform work that disturbs painted surfaces in homes built before 1978 be certified, and EPA notes that old paint on surfaces subject to constant friction, like window sills, can produce hazardous chips and dust.

What Home Inspectors Check

The ASHI Standard of Practice requires inspectors to inspect a representative number of doors and windows, and it defines a representative number for multiple similar interior components such as windows as one component per room. In practice, inspectors often open and close many windows, check that latches engage, and note sashes that will not stay open, glass that is broken or fogged, and windows that are painted or nailed shut.

Typical window findings related to locks and operation include:

• Missing, broken or non-engaging sash locks.
• Sashes that will not open, or that drop when raised.
• Bedroom windows that appear too small or too high to serve as escape openings.
• Keyed locks or security bars without quick-release on sleeping-room windows.
• Damaged screens, weatherstripping or hardware.

Inspectors do not typically measure every window against current code requirements, and the ASHI standard does not require inspecting window treatments or the seals between panes. A bedroom window that looks marginal is usually flagged for further evaluation rather than declared non-compliant. Buyers who plan to use a basement room as a bedroom should ask about the windows specifically, since a finished room listed as a bedroom without a workable escape opening may raise questions about permits, appraisal and safety. Sellers sometimes describe such rooms as bedrooms in listings even when the window is small, so it is worth checking before relying on the bedroom count.

Window Lock Costs

Costs vary by window type, brand and whether the issue is the lock or the sash. As rough 2026 guidance, offered as general ranges:

• Replacement sash lock or casement latch: often a modest parts cost per window from hardware stores or the window manufacturer; matching discontinued hardware may cost more and take time.
• Window stops or limiters: commonly inexpensive per window for simple aftermarket devices, more for manufacturer-installed opening control devices.
• Handyman installation: often a minimum service charge plus a per-window rate for several locks or stops in one visit.
• Sash repair, balance replacement or freeing painted-shut windows: typically more, and lead-safe practices add cost in pre-1978 homes.
• Full window replacement: substantially more, and usually justified by rot, failed seals, efficiency or egress problems rather than by a lock alone.

When replacing locks, check the window manufacturer’s name and model, often etched on the glass or printed on a label in the frame. Using the correct replacement hardware keeps the latch aligned with its keeper and preserves any warranty.

A Simple Window Lock Checklist

• Every window latches fully, and the sash is pulled tight when locked.
• Upper-floor windows in children’s rooms have stops limiting the opening to about 4 inches, with adult-operable releases.
• No bedroom escape window depends on a key, a tool or knowledge only one person has.
• Furniture is moved away from windows in children’s rooms.
• Every household member knows how to open the bedroom windows and release any stops or guards.
• Painted-shut, broken or nailed windows are repaired.

Our main guide to hiring a home inspector explains what an inspection covers, and the structure and exterior section covers windows, siding, roofs and related components.

References

• CPSC Urges Families to Protect Children During National Window Safety Week — U.S. Consumer Product Safety Commission
• Preventing Window Falls (Publication 5124) — U.S. Consumer Product Safety Commission
• Home Fire Escape Plans — U.S. Fire Administration
• Lead Renovation, Repair and Painting Program — U.S. Environmental Protection Agency
• ASHI Standard of Practice for Home Inspections — American Society of Home Inspectors

Buying an older Front Range home with painted-shut sashes or small basement bedroom windows? Get in touch and we can connect you with a local inspector who checks windows, egress and the rest of the house.