Bluebird House Specifications

In North America there are three types of bluebird: Western Bluebirds, Eastern Bluebirds and Mountain Bluebirds. These delightful little birds use rotten trees or abandoned woodpecker holes to build their nests. When human activities caused the loss of these nesting sites, their population went into sharp decline. On top of that, House Sparrows and European Starlings compete with bluebirds for nesting places. Providing bluebirds with proper houses has helped their population bounce back, according to the Classic Collection of North American Birds website.

  1. Location

    • Bluebirds do best with open spaces with some trees available; this provides them with a clear view of the insects on the ground that they eat and places to perch. Put the birdhouse 4 to 6 feet up on a post. Orient the entrance so it faces the closest tree available and avoids direct sun exposure. Bluebirds are territorial, so don't put another bluebird house within 100 yards.

    Materials

    • Use 5/8-inch or 3/4-inch boards to construct the house; exterior grade plywood or cedar are best. Don't use treated lumber or interior grade wood. Rough surfaces on the wood help birds exit the house, so use hardware cloth pressed firmly against the wood or etch rough spots into smooth surfaces.

    Dimensions

    • The entrance hole should be 1 1/2 inches for Eastern or Western Bluebirds; for Mountain Bluebirds and where species overlap make it 1 9/16 inches. The distance from the bottom of the hole to the bottom of the box needs to be at least 7 inches. Eastern and Western birds require a floor size of 4 inches by 4 inches or bigger, while Mountain Bluebirds need at least 5 inches by 5 inches. Make the roof overhang 3 inches to offer shade and protection.

    Ventilation

    • Drill holes at an upward angle into the sides of the house to provide ventilation while keeping out rain. For hot areas, drill 1/2-inch holes, and in northern areas 1/4-inch.

    Drainage

    • To allow proper drainage within the box, drill 3/8-inch holes in the bottom corners. Another option is to cut off small parts of the corners of the bottom piece.

    Other Considerations

    • Build one panel of the house to open and close again snugly so the box can be cleaned. Houses can be built with nails, but screws are easier to use and replace. Perches attract predators and other birds, so don't include them.