Patio doggy doors are by far the easiest type to install.  As a matter of fact, I wouldn’t even call it an installation since it can be done and undone at will, and is no more difficult than opening and closing your sliding glass door.

This type of door is less a door and more a panel that fits into your existing door.  It is designed to sit snugly in the slider track, and mate with bother slider and the door frame on the wall.  These generally are generally good fits and are only marginally worse insulators than your actual sliding glass door.

And, the best part is that when you’re going away on vacation or even for the afternoon you can simply take them out and stand them up in a corner for later use.

The argument against this type of door is that it is quite a bit more expensive than the standard door or window versions. The reason being, of course, is that they’re quite a bit bigger and have a lot of glass or plexi-glass in them. By their very design, they’re required to be large so they can fill the space in the patio door from top to bottom. It wouldn’t make much sense to have a huge open gap, functionally or practically.

How much more expensive? Well, that can vary from manufacturer to manufacturer. You could pay as much as $700 for one of these panels or as little as $150. It all depends on the materials and the make, and double-paned glass is going to push the price quite a bit further towards the high side. The benefit there, of course, is that the insulation is better so you don’t lose as much heat through the panes in the winter. If you life in a part of the country with long or harsh winters, it’s something to consider.