Bat Conservation International has a great site and free plans to build your own bat house. I downloaded the plans for the Four Chamber Nursery House and went to work. The plans are very simple to follow and are a great project for anyone with a table saw. The parts allow wiggle room to adjust measuring and construction errors. The project did take longer than I thought it would, mostly because scoring all the internal surfaces required time.
The idea of building a bat house has been stuck in my head since I visited Carlsbad Cavern a decade ago. Carlsbad Cavern has an amphitheater to watch the bats fly out of the cave each evening. It’s amazing how silent and peaceful the experience is. Bats are great to have around for reasons you can discover on sites such as batcon.org.
The plan assumes the maker intends on making two bat nurseries. I went with the plan and made two, the picture shows both. The nursery on the left does not have the front attached; the nursery on the right is complete without exterior paint. I am looking forward to completing both, painting, adding metal roofs and getting them attached to the house. Hopefully a bat family will find a new home.