Depending on the species of bird you want to keep i.e layers or broiler, the following specifications should apply, layers floor space 2sqft per bird, broilers 1 sqft per bird. Orientation should be east-west, solid wall all round should be 3ft high, remaining portion covered with wire mesh. (provide adjustable curtain where applicable. Highest point from the floor should be 8ft. Roofing material depend on your region. Concrete floor the best for easy cleaning.