Interesting at the very least. At 2 3/4" depth and assuming the front and back are both made of the same approximately 3/4" material the roof is made of, the single crevice would be 1 1/4". A bit too wide for virtually all species of bats in North America.
One possible bit of good news is that if the "recycled poly-lumber" it is made of is as slick as other such material I am familiar with (Trex, Veranda, Nexwood...) it *may* be too slick for wasps to attach nests to. The 100% recycled plastic houses (no added saw dust) that were discussed here six or eight years ago were, according to those who tested them, virtually immune to wasps since they could not attach nests. Search this forum for the the word "Rubicon" to find this past discussion.
No idea if mixed wood / plastic composite materials are quite as resistant but someone here should know... Oh, while they do not AFAIK sell a bat house made of recycled plastic, but Woodlink's Going Green line of bird feeders and houses is 100% plastic (90% recycled) and is quite likely the same base material as the Rubicon. My local 'Bird watcher supply' has a variety of these feeders so I have seen the material in person.
BTW Markcuda, where did you find the big picture of the house you posted? It is both larger and higher resolution than the one on the page you linked to. Inquiring minds want to know
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William
