If you're locked out of the house, unlocking a locked window without breaking glass isn't an option, because it's virtually impossible. Unlocking windows is obviously doable when you're in the house, but several conditions may make it difficult. The lock could be painted shut or stuck in some other way, or you may simply not know how it works. Although the operation of most window locks is easy to understand, some can be confusing, and some require keys.

A Lock for Every Window

The type of lock on each of your windows depends on what type of window it is:

Double-Hung Sash Windows

Windows that slide up and down can have :

  • A sash lock consisting of a rotating cam on the top of the outer window frame that slides under a hook-shaped latch connected to the bottom frame of the inner window.
  • Barrel locks in addition to or instead of a sash lock -- the bolts fit through the window frame and into the jamb.
  • A pivot lock consisting of a pin that fits through holes in the top and bottom window frames and locks with a 90-degree rotation. The pin may have a keyed lock, but usually it just has a pancake-shaped handle that you can grip with your fingers.

When you can't open a lock on a sash window, it's often because the lock is coated with old paint. Chipping away the paint and lubricating the lock may restore operation. The windows may also have swelled, forcing the components of a sash lock together or wedging barrel locks into the jamb. Frequently, the windows are also painted shut. When this is the case, use a simple procedure to open the lock:

Step 1

Cut the paint seal holding the window together, using a utility knife.

Step 2

Wedge a putty knife between the window and the jamb and wiggle the window frame.

Step 3

Grasp the barrel, pivot key or sash lock cam with pliers and attempt to pull or turn it as you wiggle the window. After some effort, you should eventually be successful.

Horizontal Sliders

The sliding half of a vinyl or aluminum sliding window often has a hinged catch that locks onto the window frame. In addition, there may be sliding catch on the other side of the frame that locks into a depression in the bottom track. You have to release both catches for the window to open. Because they're spring-loaded and automatically lock when you close the window, it's common for people to release one catch and become frustrated because the window won't open.

A set of horizontal sliding windows might also have a pivot lock. If the pivot gets stuck, it's often because one of the windows has come off its track . Lift the window with one hand while you turn the pivot with the other to open the lock.

Casement Windows

A casement window swings horizontally on hinges, like a door, and it can have a barrel lock, a latch-and-hook lock or even a deadbolt. When you can't open a casement window lock, it's usually because you lost the key.