This is a birdhouse for small birds such as wrens and chickadees.  I followed Audubon recommendations for hole size, hole location, hole diameter, nesting depth, drainage, and ventilation.  No perch is used since they aren't required by the inhabitants and can allow larger birds to raid the nest. I suggest "priming" the house with a few nesting materials (which might promptly be pushed out by the birds).  The design was well received by a pair of wrens who are actively using it.  The bottom can be removed via 4 small screws to clean out the nest each season.

Modified on 5-10-24 due to feedback about a gap that can occur in the print.  Thickened area at hanging hole.  Thanks for feedback!