IN Europe I am not aware of Tadarida teniotis (a cliff and tall building) using bat nest boxes. These should be installed quite high on tall buildings...
Did you know already the book: Bat House Builder’s Handbook written by Merlin D. Tuttle, Mark Kiser and Selena Kiser? http://www.batcon.org/pdfs/BHBuildersHdbk13_Online.pdf
In that project there is a lot of experience and findings... so, try and search, and ask also further. Succes!
In Portugal we had some success emulating a Tadarida teniotis roost. It was a small construction with concerte plates fixed on the walls, leaving small gaps in between. If you are using a bat box, my opinion is that it should be very large and positioned very high, maybe the minimum height is 7-8 m.
Thank you very much for the replies. I will look into The Bat Builder's Handbook, and forward all information to a colleague who is working directly with other bat conservation experts. We both live in Canada, and I was unable to find peer-reviewed articles on this subject for her.
As Dr. Arlettaz pointed out, as far as I know molossid bats of the species Tadarida teniotis don't use bat boxes. In the Canary Islands normally only two species are found in such refugia, Nyctalus leisleri and Pipistrellus maderensis. The refuges of T. teniotis in our islands are situated in crevices of cliffs and gorges.