How to Make an Insulated Pet Door

Measure the height and width of your cat or dog at its shoulders and at the base of the tail. Add four inches to each measurement to create a rectangular opening for the pet door to be installed.

Measure four inches above the bottom of the door using the measuring tape, and from that point, measure the height of the pet door opening you have calculated. Mark the height on the door with a pencil or chalk.

Extend the measuring tape to the required width for the pet door. Center the desired width measurement on the door and mark the left and right sides of the pet door with a pencil or chalk. Rule the lines for the height of the door and the width.

Saw the rectangular hole in the door carefully by following the rule lines created in Step 3. Smooth any roughness well with sandpaper.

Add a half inch to each side of the measurements taken for the pet door in Step 1. Mark these new measurements on the vinyl with chalk and rule the lines.

Cut the vinyl and hold it up to the opening in the door. Hold it from the top and push it back and forth to determine if it will swing through the opening in the door in both directions. Trim as needed so that the flap covers the door from the outside, but can still swing when pushed.

Measure and trim the insulation sheet using the vinyl flap for the door as a guide. Glue the two sheets together, pressing firmly. Let dry thoroughly. Trim any uneven edges.

Place the metal strip against the door in the desired position to secure the top edge of the pet flap in place. Put the spirit level on it to make sure the strip is level. Draw a rule line across the door.

Mark the holes to be drilled on the door by marking the holes in the metal strip with chalk. Drill the holes with the drill bit which matches the diameter of the screws you will use to mount the metal strip.

Mark the holes to be drilled in the insulated flap with chalk. Make sure the holes are positioned correctly to match the holes in the door so that the flap will hang correctly over the door opening. Drill the holes.

Screw the pet flap in place one hole at a time using the metal strip, screw, and screwdriver to secure the flap to the door.