Lowes sells fancy plywood that has grooves to interlock, it is thick stuff. But the groves are not thick and they get damaged easily by the forklifts in the store. Our lowes leaves the damaged ones on the shelf but when asked, they will sell them for $10 each instead of the almost $30. Then there are the piles of 2 x 4 x 8 #2 wood pieces that are just under $3 each. If you have a way to cut the plywood, you can make some cheap doghouse style chicken coops that have a door opening into your 8 x 8 area. If you make a 4*4 sleeping area only coop to connect to the 8 x 8 pen it should house 5 chickens. It would take 3 pieces of plywood, a pair of hinges, less than 6 of the #2 2x4x8 wood, and a cheap milk crate or free bucket for a nest. $30 for the plywood, $20 for the 2x4x8 wood, $10 or less for hinges and a latch. Less than $75 total including tax. Cheap but it would be only a night time coop it would not really house them during the day if they did not want to go out and play in the snow