Thanks so much for watching our progress and inquiring with questions. These help us to think thru this as well.
The actual pen sizes are as follows (now that we have the walls in: 3 of them are 5 1/3 foot by 9 ft. The smaller one is 5 1/3 ft X 8 ft. We kept a walkway in the front of all of the pens, so we can enter each one individually and walk through with a wheelbarrow for cleaning. The extra space at the garage door will be used to store supplies (bedding, etc). I think this setup will be nice because we can open the front doors and the garage door on nice days for ventilation as well.
We figured the space for each can hold about 5-6 birds per pen, based on about 8 sq ft per bird. Since araucana are a smaller large fowl breed, this should work out nice.
As for the floor, it is 3/4 inch plywood and built to hold a car. We do not plan to add anything and will use it as is. When we convert it back to a garage, we can always replace it if necessary.
Jody