Use the proper materials. Wood is the best material for birdhouses. Other materials (like metal or plastic) may not insulate the nest enough, so eggs or young could become chilled in cold weather or overheated in warm, sunny weather. Use rough_cut wood slabs, tree sections, or 3ǚ_inch plywood. Never use creosote_treated wood as creosote may kill the eggs or chicks.
Birdhouses should be placed in fall or winter, if possible. Swallows may use nest boxes set out during late May or early June, but owls, chickadees, and woodpeckers begin looking for nest sites during February, March and April. Always face the birdhouse so the entrance is protected from prevailing winds. Kestrel nest boxes should be placed at the edge of a forest area or on a post in an open area 12┰ feet above the ground.