Chicken Nest Box Help

[GWilson1229]

Hello, I am building some nest boxes for my girls. I am curious which would be better. I am using scrap wood to get ideas so it is not permanent yet. Curious if I should double stack the walls and back, or if one 2x4 around would be fine. I like the design of the single myself.

 

[nuthatched]

Chickens like privacy, I'd definitely do tall walls