You may choose to add double pane windows to your home for their aesthetic finish or for additional daylight. The windows have a lock to keep out intruders who might see a double pane window as a weak link in a security system or an easy way to gain entry. While the locks do not stop intruders from breaking the windows, they do provide a deterrent to opportunist thieves who might simply try opening the window from the outside. Unlocking your double pane window lock enables you to open the window for extra ventilation during the summer.
Examine the type of lock fitted to your double pane window. Sash locks have two parts: the bolt and the blocking pin. When the window is locked, you cannot lift the bolt past the blocking pin.
Push the handle part of the sash lock on the lower portion of the window away from you with your thumb. The bolt will pivot out from beneath the top part of the lock.
Lift the lower portion of the window open or turn the handle and push the window open. Slide the window closed when you are ready to re-engage the lock. Pull the handle part of the sash lock on the lower portion of the window toward you; the bolt will pivot back beneath the top part of the lock.
Locate the key for your window lock; the window installer should have given it to you. The key is usually small with just a single pin pointing downward.
Insert your key into the lock; it will only fit one way. Turn the key until you feel the barrel of the lock pop outward. Open the window.
Pull the window closed and move the handle back into the closed position. Remove the key and push the barrel of the lock inward if you have a key lock. The window is now locked again.