How to make a safe window lock for double hung window

People have turned to installing alarm systems and ensuring all the doors are well fortified just in a bid to ensure home security. One thing that most people overlook though and that makes a good entry point for a burglar is the window. While window locks for double locks are a step to ensuring security, some can easily be removed from the outside by an intruder. Here is a guide on how to enhance the efficiency of your locks using an electric drill, quarter-inch-bit and file to ensure security with double hung windows.

Window Locks

Step 1

Buy 4-inch finishing nails from your local shops, which sell window locks Edinburgh wide. You need to have one for each window and some spares. Buy the same number of small bars or round magnets

Step 2

Cut the nails to length of about 2 7/8 inches using an electric drill and file the edges. You can request the hardware store to do it for you if you cannot do it yourself.


Cut a piece of masking tape and place it around the shank a quarter inch drill bit so that it can mark exactly 3 inches from the point and act as a guide to the depth of drilling

Step 4

Use your window locks and lock the window.

Step 5

At either the upper left or upper right of the lower sash, make a drill through the lower sash frame into the upper sash. Stop where the masking tape edge is just in contact with the wood. This will leave a hole that is 3 inches deep.

Step 6

Raise the lower sash so that it is about five inches above the sill.

Step 7

Place the bit into the hole that you just drilled and into the lower sash until it meets the wood on the upper sash at the new level. Then drill another hole into the upper sash at this point and stop at the 3 inch masking tape line on the bit again.

Step 8

Insert one of the cut off nails into the hole and push to a point that the head is below the surface of the wood and therefore, cannot be removed manually.


Having the nail in the quarter inch hole allows you to enjoy your ventilation while at the same time ensuring security by locking your windows. It also cannot be removed by an intruder from the outside. Use the magnet to pull out the nail and unlock the window. You can do the same when the window is fully closed for more security. For fire safety, attach at least a magnet for each window on the window frame locks out of sight from the other outside.

Window locks for double hung windows have a major drawback of being able to be disengaged manually from the outside by an intruder through an open area of the window. Following the above steps will help you ensure that your home security window locks cannot be removed from the outside.

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