If you are doing a 10 x 8 simply sheet metal you can get 10 ft pieces at Lowes, cover the back and 5 ft down each side and put wire around the rest. You can put nest boxes in the enclosed are and also put roosts in there. This works great, you do not have to have a fully enclosed house. This design keeps the wind from them. a 5 ft wide by 10 long and 48 inches high is a great size for these. as you can use 2x4x10 an dthe 48 inch height makes it easy using 24 inch wide wire and the sheet meta is like 10 ft long by 30 inches so cut 4 in half and you have your sides back and top covered.