If you want to set up a bat house, you can buy them from some retailers or build them yourself (Setting up a bat house).
Classic (or BCI)
This model, initially developed by Bat Conservation International (BCI), is one of the most commonly used in North America. It has a rectangular shape, an open bottom and one or many lateral chamber(s). Made with plywood, this model is cheap and easy to build. Dimensions: medium size. Single chamber classic Four chambers classic
(from Brittingham & Williams 2000)Four chambers classic, pole mounting
Similar to the classic model, but with frontal chambers. Build from the well-tested design from the Nature Vincent Wildlife Trust Conservation center in England, this model is similar to the classic model, but with frontal chambers. Dimensions: medium size.