Choose untreated exterior-grade wood such as cedar, cypress, or plywood
Cut the backboard, front panels, side spacers, bottom, and roof pieces to size
Make the box tall and narrow with internal chambers about 3/4 inch apart
Roughen the interior surfaces or add grooves for bats to grip
Assemble the pieces with exterior screws and waterproof glue
Seal all exterior seams with non-toxic caulk
Leave the interior unpainted
Paint or stain the exterior with dark, water-based, non-toxic paint
Attach a sloped roof to shed rain
Install a landing pad or extended bottom opening if desired
Mount the box 12 to 20 feet above the ground
Place it on a pole or building, not a tree
Face it south, southeast, or east for warmth
Ensure it gets several hours of direct sunlight
Keep the area below clear of branches and obstacles
Install multiple boxes if you want to attract more bats
Check that the box is secure and stable
Avoid using pesticides near the box
Inspect the box periodically for damage or pests