Bat houses have their place but provide only temporary habitation for bats.
Bat houses are primarily used by bats on the hottest nights of summer. Overnight temperatures must be sufficiently warm to support this kind of roosting site. On cooler nights bats return to their primary hibernaculum.
It is worth noting that bats cannot winter in these structures as they cannot produce sufficient body heat to prevent freezing solid. Bats are extremely susceptible to hypothermia and death due to exposure!
Bat bugs and bat guano may also become an issue if a bat house is installed on a structure.
However, bat houses DO NOT keep bats from infesting near by structures. The only permanent solution is getting your home bat proofed by a NWCOA qualified technician!