Bluebird houses are ideally built between 4 and 6 feet above the ground, according to HowStuffWorks. The house should be attached to a mounting pole with a baffle to keep animals from climbing up and disturbing the nest.
The ideal bluebird house is about 5 inches square and between 8 and 12 inches tall. The opening to the nesting area should be only 1 1/2 inches wide to keep out possible predators. Bluebirds prefer openings that are high on the wall to allow them to enter the nesting area well above the actual nest.
Bluebirds are attracted to houses that are located in open woodlands or on the border between forest and meadow. Bluebirds build nests near foraging spots with plenty of trees or other perching areas available.