How to Build a Dog Air-Lock Door

The air-lock concept is familiar to a wide range of institutions, from hospitals to prisons to NASA. It means using two doors to control access to an area by assuring that one of the doors is always closed. In your home, an air lock for dogs is both a security device and a thermal barrier.

Things You'll Need

  • 2 lockable dog doors of appropriate size
  • 2 sawhorses or other supports
  • saw
  • drill and bits
  • screwdriver
  • measuring tape
  • level
  • pencil

Instructions

    • 1

      Measure your dog. The door opening should be only as large as the dog needs to get through, usually 2 inches wider than the widest part of his body. Measure from the lowest point on his undercarriage to the floor, and mark the bottom edge of the door no higher so the dog can step through it without jumping.

    • 2

      Find a space in your home that has at least two doors, one that leads from that space to the outside and one that leads to the home interior. An attached garage with a door that leads to a closed kitchen, a laundry room or a mudroom makes a good candidate for an air lock.

    • 3

      Check to see if the doors between the garage and the exterior and between the garage and the house are made of wood, metal or plastic; dog doors can be installed in all of these. If you have sliding glass doors, you can use a snap-in dog-door section available from pet supply retailers. Find a dog door that best matches your dog's dimensions and is made for the type of household door you'll be installing it in. Instructions for installation, and tool required, vary among different retail dog doors.

    • 4

      Remove the household exterior door from its hinges and lay it across the sawhorses for support. Lay the template that comes with a prefabricated dog door on your door and follow the instructions provided to cut the hole and install the dog door. Be sure to install the house-side dog door with the lock inside the house for security purposes. Hang the exterior door on its hinges. Repeat the process on the other door.

    • 5

      Consider what amenities you may wish to add to the air lock itself to make it a refuge for your dog. Consider adding climate control. Otherwise, provide a well-padded crate or kennel to give your dog a warm place to curl up. Other creature comforts can include a bed, and a food dispenser. Since the dog needs water available at all times, the air lock should have water.