installing small cat flap through interior wall
We are putting a second floor on our house (all new construction) and would like to have a "cat tunnel" through the bedroom wall to the laundry room, where her litter box will be.
All the cat doors I can find online are designed to be installed through a door, and are not deep enough for a wall. There are a couple of larger doors (meant for small dogs and/or cats) that can be installed with an additional "wall extension" kit, but we really don't want something that big. Also, they're meant for exterior use and have a lot of weatherproofing that we don't need.
I'm wondering if the contractor can build a tunnel through the wall and install a cat flap just on one side -- do you think that would be possible? Any better solution that you can think of? I haven't talked to him about it yet because I have no idea how reasonable that is and didn't want to sound like an idiot.