Door Security ($0 — Just a Screwdriver)
Replace your deadbolt's short strike plate screws
This is the single highest-impact free change you can make. Most door kick-ins work because the door frame splits — not because the lock fails. The fix: remove your deadbolt strike plate and look at the screws. If they're 3/4-inch or 1-inch, replace them with 3-inch screws that go into the wall stud, not just the door frame. A 3-inch screw holds against 150+ lbs of kick force. A 1-inch screw doesn't. Screws are $2 at any hardware store.
Check your door hinges — are they on the exterior side?
Exterior doors should have hinges on the interior. If your hinges are on the outside (visible from the street), a burglar can knock out the hinge pins and remove the entire door — bypassing the lock entirely. If this applies to you, install security hinge bolts ($10 at a hardware store): metal pins that lock into the opposite side of the frame when the door is closed.
Secure your sliding door with a bar
Sliding glass doors have notoriously weak locking mechanisms. The simple fix: cut a wooden broom handle or a length of 2x2 lumber to fit the track. This prevents the door from being slid open even if the lock is defeated. Cost: $0 if you have an old broom, or $5 for a piece of lumber.
Lock your garage door — and fix the emergency release exploit
The garage door emergency release cord can be triggered from outside using a coat hanger inserted through the gap at the top of the door. The fix: add a zip tie through the hole in the emergency release lever — it still works with a sharp pull in a real emergency, but a coat hanger can't manipulate it. Cost: $0.
Window Security ($0–$5)
Pin your double-hung windows
Double-hung windows (the kind that slide up and down) can be pinned closed with a nail. Drill a downward-angled hole through the inner sash into (but not through) the outer sash. Insert a nail. To open the window, pull the nail out. To lock it: push the nail back in. This prevents the window from being opened from outside even if the latch is defeated. Drill bit and nails: under $2.
Add window stops to limit how far windows open
Even if you want to leave windows open for air, you don't want them to open wide enough for a person to climb through. Window stops ($3–5 each) let you ventilate while limiting opening to 4 inches. This also works for AC units — leave enough airflow, but not enough for entry.
Close your curtains and blinds at night
A burglar casing your home can't steal what they can't see. At night, from the street, a lit interior with open curtains shows exactly what you have and where it is. Pull your blinds after dark. This costs nothing and removes the window-shopping stage of most residential burglaries.
Deterrence and Visibility ($0 Behavior Changes)
Trim bushes and shrubs near doors and windows
Overgrown landscaping near entry points provides cover for a burglar to work unobserved for minutes at a time. Trim hedges near your front door, garage, and any ground-floor windows to below 3 feet. Cut back tree branches that overhang a second-floor window. This is the CPTED (Crime Prevention Through Environmental Design) principle of natural surveillance.
Install motion-sensor lights on all entry points
Motion-activated lights are one of the most effective deterrents in the criminology research. They're also cheap: $15–25 at any hardware store, easy to install in an existing bulb socket. Cover: front door, back door, garage, side gate. Any point where someone could approach unseen. The sudden light startles and exposes — and signals that the property is equipped and watched.
Don't post vacation photos until after you return
You're not paranoid — this is real. Burglars monitor social media. A geotagged photo from a resort 500 miles away with "five days in Cancun!" in the caption is a public announcement that your home is empty. Post vacation photos after you're home. If you must post live, don't include location data and avoid giving away the dates you're away.
Stop your mail and deliveries when you travel
A pile of mail and packages on the doorstep is the universal "nobody's home" signal. USPS mail hold is free at usps.com. Ask a neighbor to collect packages. Or use Amazon's package hold at a locker or delivery preference settings. An overflowing mailbox is one of the most reliable signs used by burglars to identify vacant homes.
Leave a car in the driveway when you travel
An empty driveway during the day (especially on a weekday) is a strong occupancy signal. If you're traveling and a neighbor can park in your driveway, ask them to. If you have two cars and are taking one to the airport, leave the other in the driveway. A car signals a body — no car often signals opportunity.
Use light timers inside the home
A smart plug ($8) or mechanical timer can turn on interior lights and a TV or radio on a schedule. This simulates occupancy patterns. Randomized timing is more convincing than constant-on. Set different rooms to turn on at different times in the evening. The goal is: to someone watching the street, the home appears occupied.
Social Security ($0 — Your Neighbors Are Your Best Alarm)
Introduce yourself to your immediate neighbors
Criminology research is consistent: neighbors who know each other are more likely to notice and report suspicious activity. You don't need a formal neighborhood watch — just a five-minute conversation with the people on each side and across the street. "Hi, I'm [name], if you ever see anything odd at my place feel free to reach out" is enough. Exchange numbers. This is the most underrated free security improvement on this list.
Tell a trusted neighbor when you'll be away
A neighbor who knows you're in Miami for a week can call police if your front door is open at 2am — a neighbor who doesn't know your travel patterns might assume it's fine. You don't have to tell them your full itinerary. "Hey, I'll be out of town until Thursday — keep an eye out?" is all that's needed.
Know which neighbors have cameras — and where they point
You may have better camera coverage than you think, or useful coverage gaps you should fill. A quick walk around your block tells you who has Ring doorbells, Arlo cameras, and other visible systems. In the event of a crime, footage from neighbors is often more useful than your own — different angle, further back, better coverage of the approach.
Quick Wins That Cost Under $30
Motion sensor porch light — $15–25
Replaces your existing exterior light fixture. Most burglaries happen at night; sudden illumination is a reliable deterrent. No electrician needed if you have an existing fixture.
Window/door alarm sensors — $6–12 each
Stick-on magnetic sensors that sound a 120dB alarm if the window or door opens. No monitoring, no subscription. Works as a simple alert. Brands: GE, Doberman.
Door wedge alarm — $8
Wedges under the door and sounds alarm if the door moves. Travels well (ideal for hotels), but works at home too. Especially good for back doors and rooms you sleep in.
Door reinforcement kit — $30–50
Replaces your entire door frame strike hardware with steel that anchors into the stud. Stops door kicks cold. Door Armor and Strikemaster II are the leading brands.
When you're ready for a monitored system
SimpliSafe adds 24/7 professional monitoring on top of everything above — no contract, starts at $19.99/mo.
Frequently Asked Questions
Are security system yard signs effective even without an actual system?
They have some deterrent effect, but less than a real system. A sophisticated burglar will notice the lack of actual sensors on windows and doors. A real system with real sensors is always better. However, a sign from a reputable company (ADT, SimpliSafe, Ring) does add some psychological deterrent, especially against opportunistic rather than targeted burglars.
Does a dog help deter burglars?
Yes, significantly. The UNC criminology study found dogs were one of the most frequently cited deterrents — both because of the noise and the unpredictability. Even a medium-sized dog that barks at strangers is a meaningful deterrent. However, dedicated burglars know that most dogs can be distracted with treats through a fence.
How many burglars case a home before breaking in?
The research varies, but most residential burglaries are opportunistic rather than pre-planned. The majority of residential burglars spent less than a minute deciding to target a specific home — they're looking for quick signals of vulnerability (no car, overgrown bushes, no lights, no visible cameras). This is why visible deterrents work.