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How to Secure Basement Windows and Window Wells

By Guardian Angel DIY · Updated October 27, 2026 · 9 min read

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Basement windows are easy to forget. They sit low, they are often old, and they are hidden behind shrubs or sunk into a window well where no neighbor can see them. For the same reasons, they are attractive to anyone looking for a quiet way in. At the same time, a basement window may be an escape route for a finished bedroom, so security must never get in the way of getting out. This guide shows how to secure basement windows and window wells while keeping them safe in a fire.

Why basement windows are targeted

Four features make basement windows a favorite of people looking for an unseen way in.

• They are out of sight. Many sit at the back or side of the house, below a deck or behind plants, where no neighbor or passer-by can see someone working.
• They are easy to reach. They are at or near ground level, so no ladder is needed.
• They are often neglected. The latches are old, the frames may be rotted by damp, and the window may not have been opened in years.
• They are not always protected. Alarms, lights and cameras tend to cover the doors, leaving the basement dark and unwatched.

Not every basement window is large enough for a person to enter. A small hopper window may be too narrow to climb through, though glass breaks easily and a thin window can still be used to reach a latch or a door. Treat any window that a person could fit through, or that gives access to the inside, as a priority.

Step 1: Take inventory (20 minutes)

Walk around the house and the basement and make a short list. For each window, note:

1. Size. Could a person fit through it?
2. Type. Is it a sliding, hopper, casement or double-hung window, or glass block?
3. Latch. Does it lock, and does the lock work?
4. Frame. Is there rot, cracking or soft wood?
5. Well. Does it have a window well, a cover and a ladder?
6. Purpose. Is it the escape window for a bedroom or a finished room?
7. View. Can it be seen from the street, or from a neighbor's window?

Those last two items decide how you secure it. A window that is a required exit can be made harder to enter, but it must remain easy to open from inside.

The escape rule

Building codes in most places require bedrooms, including those in finished basements, to have at least one window or door that opens from the inside without a key, a tool or special knowledge, and that is large enough for a person to climb through. The window well outside such a window must also be big enough to let people out, and deep wells often need a permanent ladder or steps. Requirements vary by location and by the age of the house, so check your local code.

For security this means one simple rule: on any window that is an exit, use only devices that anyone can release by hand in seconds. Never use a keyed lock, a screwed-shut window, fixed bars or a cover that needs a key or a tool. Practice opening each escape window, and have everyone in the house do the same in the dark.

Fix 1: Fix the latch and the frame

Begin with the basics. Open and close each window, lubricate the track and replace broken latches. If the frame is rotted or soft, repair or replace it first, because a lock screwed into soft wood holds nothing. For double-hung basement windows, our guide to securing windows explains how to replace weak latches and add a pin. Sliding and hopper windows are covered next.

Fix 2: Add a lock suited to the window type ($10 to $13 for four)

Many basement windows are horizontal sliders, which often have a weak factory latch. An add-on lock fits on the track or frame and prevents the window from opening, or limits how far it can go. Most install without drilling, and a four-pack can cover a whole basement. Fit varies by frame, so measure first. On an escape window, choose a lock that releases quickly by hand.

Fix 3: Strengthen the glass ($65 to $75 per roll)

Basement windows are low and often hidden, so they are the best candidates for security film. A clear film applied inside the glass does not make it unbreakable, but it holds the pieces together, which slows entry and adds noise. It is a good fit for any window that is at ground level, out of sight or beside a door. One roll covers roughly one large window or several small ones, so choose the most exposed windows first.

Clean the glass thoroughly, apply the film with the solution and a squeegee, trim the edges carefully, and allow time to cure. Most mistakes come from dirt and rushed trimming.

Fix 4: Cover and manage the window wells

A window well is a sunken space that lets light and air reach a basement window below grade. It also creates a hidden pit where someone can work unseen, and it collects leaves, debris and water. A cover helps in several ways. It keeps out debris, rain and animals, and it makes it harder for someone to stand in the well and work on the window.

• Choose a cover that can be opened from inside. A clear polycarbonate cover or a grate must lift or release without a key or tool if the window is an exit.
• Lock only what you can unlock quickly from inside. A cover that clips shut from the inside is fine. A padlock on the outside may trap a person in a fire, and it may be restricted by code.
• Keep the well clear. Remove leaves and debris so that the window can open, and so water does not collect.
• Keep the ladder in place. If the well is deep, a ladder or steps may be required, and it must be usable.
• Watch drainage. A well that floods will damage the window and the frame.

Fix 5: Be careful with bars

Security bars can make a window much harder to enter, but they are a trap on any window that is an exit. If you use bars on a window that people may need to use for escape, they must have a quick-release mechanism that opens from inside without a key, and many places restrict their use on sleeping rooms. A safer plan is to use bars only on a small, non-exit window, and to rely on film, locks and covers for the rest. Check your local code first, and never weld or screw a bar permanently over an escape window.

Fix 6: Light, sight lines and an alert

• Add a motion light over the area where wells and windows sit, so anyone working there is lit. Our lighting guide explains which type to use.
• Trim shrubs so that a person cannot hide beside a window or in a well.
• Use a window chime. A battery-powered sensor on each basement window sounds when it opens. A multi-pack is about $15 and needs no wiring or subscription.
• Cover glass from inside with a curtain or blind, so no one can see what is in the room.
• Secure the basement door, especially a walk-out or bulkhead. Use our guide to reinforcing a door.

What it costs: a simple plan

Common mistakes to avoid

• Forgetting the basement. It is the least-protected part of many homes.
• Blocking an escape window. Safety comes first.
• Padlocking a well cover. It can trap people in a fire.
• Fixing locks on rotted frames. Repair the wood first.
• Leaving wells full of debris. A clogged well hides a person and floods the window.
• Skipping the door. A walk-out basement door needs the same protection as the front door.

If you rent

Many basement apartments rely on small windows. Use removable locks and wedges, film that peels off cleanly, chimes and curtains. Ask your landlord about latches, covers, wells and egress. A missing or painted-shut escape window is a safety problem to put in writing.

Frequently asked questions