Build a birdhouse for purple martins that has several compartments. The minimum size of each compartment is 6 inches square, but 7-inch by 12-inch compartments attract more birds. The opening to each apartment should be a 2-inch to 2 1/4-inch opening that is 1 inch above the floor.
Once the birdhouse is complete, paint it white to attract the most birds. White birdhouses reflect heat, allow males to show off their plumage and highlight the dark openings into the house.
Place the birdhouse on a telescoping pole near the house, but away from wires, trees or shrubs. Martins have evolved to favor locations near humans because there are fewer predators there. However, shrubs or vines growing around the support pole, wires and trees allow squirrels and other predators to jump into the apartment and rob the nest. The telescoping pole allows the landlord to lower the birdhouse to evict competing species that drive off the purple martins. Do not be afraid to lower the birdhouse temporarily, even if martins are nesting in it. The process does not cause them to relocate.
If the birdhouse is new, open it about four weeks after the first scouts appear in the area. This reduces the chance of competing species nesting in the house but is early enough that most of the martins are in the process of migration, increasing the chances of nesting birds.