19 years ago I built a Monica's chicken house. It's 4'x8' I used metal roofing and hardware cloth wire. The wood was not pressure treated so after about ten years the bottom got a bit saggy. I am in the process of repairing it. It is a sturdy build. It has served me well as a grow out pen.
The one thing that I have since changed is the height. It's fine for a child to access, but not an adult. Also the area under the little house is not accessible in case you need to retrieve a sick bird.
I have completed the rebuild/remodel and posted pictures. https://www.backyardchickens.com/articles/monicas-house-rebuild.79222/