So you want a super tight house, but you still want your pets to have access to the outdoors? What to do? Traditionally, you go to a big box home improvement store or a pet store and buy a pet door that is the equivalent of hacking a giant hole in your house. Kind of sad after you have spent months chasing down every minute hole in your house.
Now there is an alternative. An airtight pet door, made in the U.S.A. Freedom Pet Pass energy efficient pet doors.
http://energyefficientdogdoors.com
I just got mine in the mail today. It should be fun training the cats to use this thing, but I look forward to not having a super leaky hole in my door...