First of all, you should determine the height of your door track. A common mistake of many dog owners is that they only make an assumption or estimate on the measurement of the dog door. What they usually forget is calculating all the portions of it, from top to bottom, using a measuring device. Remember that adjustment ranges for every dog door.
Be particular with the design too. Check if the color of the framing is appropriate to the design of the dog door. An eye for detail and harmony can make or break your over-all interior. Most designers recommend the use of neutral colors like aluminum white and bronze as they can easily blend with other colors inside your house.
It also pays a lot if you inspect the materials used on your walls. Assess if they match the materials of the patio dog doors you want to purchase. If you think installing them will not coordinate with your patio, better not do so. For sure, you can find other alternative dog door options that will suit your preferences.
Determining the measurement of the door flap must also be done. Make sure that it is big enough so that your canine can easily pass through it. You must provide a huge amount of space to allow possible adjustments in the futre. Add at least an inch in every side of the minimum width.
As regards to flap dimensions, know the the flap height and rise. If the height of the flap is measured accurately, you will make the life of your dog easier as he will not to hunker down in order to pass through the patio pet door.