Some common wooden birdhouse designs include nesting boxes for bluebirds, flickers, wrens, purple martins and woodpeckers, as well as designs for phoebes and robins, ducks and American kestrels. Most wooden birdhouse designs are enclosed, but platform and gazebo designs are suitable for birds that nest near the ground, on walls or on fence lines. Creative decorative designs for wooden birdhouses are also common.
Different wooden birdhouse designs accommodate the natural size and behavior of a specific species. For example, bluebird houses are simple rectangular boxes that are about 6 inches wide by 10 inches long, and they are about 8 inches in height. A round hole at the top of the box measures between 1 and 2 inches in diameter, and the roof protrudes slightly over the entrance. Bluebird houses are post-mounted in open country or semi-open grasslands for eastern bluebirds. Western and mountain bluebirds prefer semi-open country with some trees and shrubs.
Most birds only occupy a single compartment with a single entrance, and one of the most critical design details is that the size of the entrance hole is big enough for desired birds but too small for predators and unwanted species. Otherwise, wooden birdhouses may have a flat or pitched roof and varied compartment dimensions. Purple martins nest in colonies, so designs for purple martin houses include multiple entrances and they frequently feature several levels. Platform nesters, such as robins, phoebes and barn swallows, prefer designs that basically provide a shelf with an overhang for a roof. Tree swallows, wood ducks, screech owls, American kestrels and bluebirds enjoy houses carved out of wooden logs.
Creative decorative designs for wooden birdhouses often follow themes, such as cottages, fishing and boating, beach houses, floral houses or whimsical characters, in a wide variety of shapes and sizes.