Close that big door and use only when cleaning maybe.
Use the smaller door for the main door.
Either single perches as I pictured or shelfs will work.
Pigeons like things to be as dry as a popcorn fart, so if ya know it gonna rain...close the windows.
Fix the holes in the floor...
Keeping squirrels and cats out is going to be a task, this is why I say to place the entrance/exit up as high as possible.
Also all perches should be up as high as possible, but far enough down from the ceiling as to allow them room to land on the perch, squirrels wont bother your birds (that much) but you still do not want them in there, your birds may eat there poop and become sick thinking its a seed...hey it happens...best to keep all rodents out.....
If a stray cat gets in, the birds will have a fighting chance to get out, if you place the entrance up high and the perches also....
Good Luck
Arty

Maybe you don't want to free fly, then take that big door and cut a window in it, and frame the rest of the deck I see , you can use chicken coop wire fencing to enclose.
Then you wouldn't need to cut a hole for them to come and go from.
Just an Idea...


Frame in with 2 by 2's, and ad perches in that area to for the birds to perch and enjoy the outdoors and sunshine.

Thanx for the nice drawing! I will figure it all out.
Abigail is starting to follow me around a little ..... when she is up on the roof ledge and I walk away she follows along the roof with me! I love this bird! I was pulling weeds today and she was up on the canopy.....I was below her in view....well, when I looked up she was laying like a duck with her head looking down where I was, half asleep! She is tooooo cute! I just hope she flies on my head one day.....she is funny when I go out the side door she stretches her neck to see if it is me! If it is my boyfriend she takes off. She must watch from a tree because 5 min. after he goes back in the house she comes back! She is just tooooo sweet! I am so
glad she found me and I am glad I found the nicest person in the whole entire Pigeon/Dove world! ARTY!

Thanx again for all your help!

Geeee, Thanks for the kind words.
Abi has found a true friend when happening upon you, as well as all of us here on ParrotChatter.
I pray your relationship grows.

Arty

You got that right Donna.