Thanks! The reason I'm thinking of 3 boxes is I may want to let a hen raise a clutch of eggs. If I do that, then I still have a nestbox +1 for the other hens. The change in materials probably won't be significant-- unless the extra box pushes me to an extra sheet of plywood.
Here's a great article on broodies: https://www.backyardchickens.com/ar...rst-turkey-strut-to-weaning-the-chicks.76878/
I was thinking this exact thing! With a mobile coop. you can possibly make "flaps" that fold down for the move to new spot, but when placed they can be opened up, and propped. Due to wind, they need to be secured somehow. But SHADE is very important
Here's a good way to make a safe, adjustable prop for top-hinged windows: https://www.backyardchickens.com/articles/window-support-for-top-hinged-windows.74810/