In article ,
Jeff Thies wrote:

I'm putting in a new door, as well as residing/rebuilding that part
of the house, and I'm thinking of putting in the cat door in the wall
rather than the door.

I'd like to avoid some obvious problems, like water in the walls. So
either make a channel out of backer board or find about a 6" tube. Slope
it down toward the outside so it drains and has a bit of wind blocking.

Those are my ideas. I don't always have good ideas. Something else?
The commercial cat doors have not been holding up for me, but they get a
lot of use.

Jeff

Hmmm... or maybe make it a bit longer than necessary, and have 2 doors
to form a little 'airlock'? The upsloping 'tunnel' part could even run
parallel to the outside wall face... cats are nimble enough to make a 90
degree turn.

Just thinking out loud... I've never done or been involved in such a
project.

Good Luck!

Erik