Windows are the most neglected entry point in residential security — and burglars know it. The front door gets the deadbolt, the camera, the attention. The side window with the broken latch gets nothing. If you want to know how to secure windows from burglars properly, you need to understand which vulnerabilities actually get exploited and fix those first.
I’ve done post-break-in security assessments on homes where the front door had a commercial-grade deadbolt and the entry point was a first-floor window with a plastic latch that flexed open in under three seconds. Here’s how to not be that house.
Why Window Security Is Consistently Overlooked
Most residential windows ship with latches that are designed to keep the window closed, not to resist forced entry. They’re typically thin zinc alloy or plastic, they engage with about a quarter-inch of contact surface, and they flex under moderate lateral force. A screwdriver slipped into the gap can pop the vast majority of residential window latches without breaking anything — which means no noise and no obvious evidence of forced entry until you check.
The FBI’s Uniform Crime Reports consistently show that windows account for approximately 23% of home burglary entry points. That’s nearly one in four break-ins. Yet most homeowners never do anything about window security beyond closing the latch.
The Window Pin Method (Free, Takes 5 Minutes per Window)
This is the fix I install on every house I consult on, including my own. Drill a downward-angled hole (about 30 degrees downward) through the inner window sash and partway into the outer sash. Drop a hardened steel pin, a cut-down carriage bolt, or even a large nail into the hole. The window physically cannot be opened while the pin is in place — no amount of latch manipulation matters.
To open the window from inside, you pull the pin out, open the window, replace the pin to hold it at the height you want. It takes two seconds. The materials cost under $5 for your entire house. This is the most underused security upgrade in residential security.
Works on: double-hung windows (most common residential type). For sliding windows, a different version applies — see below.
How to Secure Sliding Windows and Patio Doors
Sliding windows can be lifted out of their tracks from outside if the track isn’t properly blocked. The fix: cut a wooden dowel or a piece of broomstick to fit in the track, blocking the window from sliding open. For patio doors, the same principle applies — a Charlie bar (a hinged bar that drops into the track) or a cut-down wooden rod prevents the door from sliding regardless of whether the lock is defeated.
For sliding windows, also check whether the window can be lifted up and out of the track from outside. Many can. Anti-lift blocks — small plastic or metal devices that screw into the track — prevent this. They’re about $5 at any hardware store.
Window Security Film: What It Does and Doesn’t Do
Security window film is 3M Safety Series or similar products — thick polyester film applied directly to the glass. It doesn’t prevent glass from breaking, but it holds the shards together after impact, making it much harder to reach through and open a latch. A standard window break takes less than three seconds. A window with security film applied correctly can take 30–60 seconds or more to breach, which is usually long enough that an intruder moves on.
The 3M Safety Series 8-mil film runs about $2–4 per square foot installed professionally, or you can DIY it for around $1–2/sq ft in material costs. For ground-floor windows in higher-risk areas, it’s a meaningful upgrade. For a second-floor window that requires a ladder to reach, it’s probably not worth the investment.
One thing film doesn’t address: a burglar who breaks a window on purpose knowing the film is there, with the time to work through it. Film is a deterrent against opportunistic smash-and-grab, not a barrier against a determined attacker with time.
Window Sensors: The Cheapest Electronic Layer
A window sensor is a two-piece magnetic contact sensor — one piece mounts on the frame, the other on the sash. When the window opens and separates the magnets, the alarm triggers. They cost $10–25 per window as standalone units, or they come bundled with most security systems.
Window sensors are one of the highest-value components in a home security system. They’re cheap, reliable, and catch break-ins at the moment of entry rather than after the fact. If you’re building a DIY security system, prioritize sensors on ground-floor and basement windows over cameras on those same windows — the sensor triggers an alarm in real time, the camera just records what happened.
Glass break sensors are a complement, not a replacement. They detect the acoustic frequency of shattering glass and trigger an alarm even if someone breaks the glass without opening the window. Worth adding to rooms with large windows or where window sensors alone wouldn’t catch glass-breaking entry.
Landscaping and Visibility: The Often-Skipped Layer
Dense shrubs planted under or adjacent to windows give burglars concealment to work. A study by the University of North Carolina criminology department found that concealment near entry points is one of the top factors burglars consider when selecting targets — the same research that showed cameras deter opportunistic crime.
Trim shrubs to a maximum of 3 feet below ground-floor windows. If you want plants for aesthetics and security simultaneously, thorny varieties work well — roses, pyracantha, or hawthorn along the foundation make climbing through a window a painful proposition.
Window Bars and Grilles: When They Make Sense
Window bars are the most physically secure option but come with serious trade-offs. Fixed bars prevent emergency egress — a fire code violation in many jurisdictions and a genuine safety hazard. If you’re going to use bars, use swing-away or quick-release designs that allow egress in an emergency.
Bars make the most sense on basement windows and in high-risk urban areas where forced entry attempts are genuinely more frequent. For most suburban homeowners, the combination of window pins, sensors, and security film is a better solution — it achieves strong deterrence without the aesthetics and egress issues that come with bars.
A Practical Window Security Checklist
| Fix | Cost | Difficulty | Impact |
|---|---|---|---|
| Window pins (double-hung) | Under $5 total | Easy (30 min for whole house) | High |
| Track block (sliding windows/doors) | Free–$5 | Easy | High |
| Anti-lift blocks (sliding windows) | $5–15 | Easy | Medium |
| Window sensors (alarm system) | $10–25/window | Easy–Medium | High |
| Security film (ground floor) | $1–4/sq ft | Medium | Medium |
| Trim foundation shrubs | Free–$50 | Easy | Medium |
| Glass break sensors | $20–40/room | Easy | Medium |
| Swing-away window bars (basement) | $80–200/window | Hard (professional install) | Very High |
Start at the top of this list. Window pins cost nothing and take an afternoon. Sensors get you real-time detection. Film and bars are for higher-risk situations or specific problem windows.
Window security doesn’t require an expensive overhaul. The basic security checklist for any home addresses windows as part of a broader set of fundamentals — and in that context, the window pin and a $15 sensor are usually the right starting point before you invest in film or bars.
Window Security for Renters and Apartments
Renters face a real constraint: you cannot drill into window frames or install permanent hardware without landlord permission. But you are not out of options.
Window track blockers. A cut wooden dowel in a sliding window track requires no drilling and no damage. When you move out, you take it with you. This is also the most effective sliding window security fix for renters — and it costs nothing.
Portable window sensors. Battery-powered window and door sensors from SimpliSafe, Ring Alarm, or Wyze stick on with adhesive and remove cleanly. They trigger an alarm if a window is opened unexpectedly and work equally well in apartments as houses.
Security film. Window security film is adhesive and can usually be removed, though removal is labor-intensive. Check your lease. In most cases, landlords allow it because it does not damage the glass — it just bonds to the surface.
For ground-floor apartment windows facing alleys or high-traffic areas, the combination of a track blocker, a portable sensor, and security film gives you most of the protection of permanent hardware without requiring a single screw.
Frequently Asked Questions
What is the cheapest way to secure windows?
Window pins (a nail or bolt drilled through the inner sash into the outer sash) cost under $5 for your entire house and prevent double-hung windows from being opened from outside. For sliding windows, a cut wooden dowel in the track costs nothing. These two fixes take an afternoon and cover the most common window entry methods.
Do window alarms actually work?
Yes — as an alert layer. Window sensors do not physically stop entry, but they trigger an immediate alarm when a window is opened, which alerts you and, if connected to a monitored system, dispatches a response. Combined with physical barriers like window pins, sensors form a two-layer approach: the pin slows entry, the sensor alerts if entry is attempted.