Suggestions for 100-200 bird coop

[Percheron chick]

I do not have a link and cannot readily find it on a search, but one member here has/had coops with droppings pits under the roosts.

The pits were covered with 2x4 wire to keep the chickens out and they opened at the back of the coop so that the manure could be readily shoveled away.

I have something like this. (Came with the house). I have a bench structure made from 1x2 under the roosts with wide spacing between the boards. Run a rake over the top and any stuck on poop falls to the ground. Access is from the front covered in wire to keep them out. I throw a thin layer of bedding down to keep the poop from freezing to the concert floor. Only scoop it out about 4 times a year. Works well.