The Woodpecker Birdhouse has a curved heavy-gauge copper roof which is treated to give the appearance of timeworn copper - something called patina. The birdhouse is constructed using long-lasting poly-wood. It will not require painting and will not rot or peel. To clean the compartment simply unscrew the finial and remove the copper roof. The dimensions are: 25 inches high x 12 inches wide. The hole = 1.5 inch diameter. A 4-inch x 4-inch post mount is included so it can be mounted on your 4 x 4 (actual size = 3.5-inches x 3.5-inches) wooden post. The roof has been given three coats of clear lacquer to preserve its antique look