Quote Originally Posted by emily_the_spoiled
Someone I know put a cat flap in the wall next to the door, but because it was letting in cold air they built a little porch attached to it. So basically Harry (the cat) walks through the flap and then through a small room and out the door. This helped cut down the drat and there was no need to put it in the window
I have a couple friends who have a cat/door door right in the wall!
One of my friends had a cat door installed in her door just this past spring and it is a double glazed door. It was like $100 more for the installation *if I remember correctly*. I do know that it wasn't a whole lot more.