We are in the middle of coop contruction and to make a secure door we can shut nightly for the chickens my husband installed an 8" pet door to get the chickens in and out of the run. This is our first time having chickens and 2 of our chickens our Buff Cochins. All of the chickens we have picked out are not tiny breeds and all will range in the 6.5-8 lb range. I didn't realize just how big the Cochins will get though. The book I just saw stated they get to be about 9-11ish lb for hens. Will to cochins fit through this door? My others are listed in my signature. I knew cochins were big birds when I picked them out I just thought they ranged in the 8lb range. I figure if they won't all won't be completely lost maybe I can find someone locally that would be willing to do a pullet exchange or something. Thanks.