https://jsfiddle.net/lierorgan1/owqxbpgr/ Installing a cat flap might seem intimidating however it's actually quite easy to do by following the correct instructions. First, decide how high you want the cat flap to be (on average the belly height). Note this on the door and then use the template included as a reference to drill. If you have a young kitten, prop the door slightly open and gradually encourage it to go through. Reward the kitten as it goes through. Measure the Door A cat flap allows your pet to enter and exit your home at any time. This will keep your cat healthy since it will ensure it gets enough exercise and be able to go back inside if it gets trapped in the elements during bad weather. This can reduce the time you have to let your cat go in and out and make your home safer by letting you know when it's gone. It is essential to ensure that the cat flap is set up properly to stop your pet from being pushed through or escaping through it by other animals (e.g. dogs). It is essential to measure the height of your pet's belly as well as the doorway of your house so that you can ensure that the flap is at the proper height. If your cat is a little larger or shorter than the normal, you can adjust the flap's position by moving it up or down by a tiny amount. Next, use a spirit-level to mark the center of the door. This is where you will install the flap. With the markings as a guide, take the jigsaw and cut the shape of the flap inside the door. Once you have cut out the area, sand the edges of the door to smooth the surfaces. Then drill any fixing holes required. The process of installing the cat flap isn't as difficult as you may believe and it shouldn't take more than two hours to finish the entire process from beginning to the end. However, the process could be slightly more complicated if you need to fit it inside a uPVC or composite door as these doors come in a wide range of thicknesses that can affect the way the holes are cut and the type of door