The first couple bee houses I ever made were from two large plastic cans, one a large plastic Folgers can and the other a large Carnation non-dairy creamer can. I cut native cane into lengths and filled the plastic cans after drilling some drainage holes in the bottom side. The cane segments worked well but needed to be replaced. Also, in our hot and humid summers, they never held moisture. They were out year round and moisture never seemed to be an issue. They were overhead up under roof eaves and the opening oriented away from the normal direction of inclement weather.. It was only on the third year that I noticed cuckoo wasps camped out around two of them. Now I really worry about Houdini flies.
Below is another experiment. I took PVC scrap, got a cap for one end, and cut an overhang into the other. I filled these regular paper straws. The small one has only thinner straws while the larger one has a mix of two types. It looks like there have already been emergences this year. I'm going to cut them open in the next few days to inspect. Both size straws were used by insects. They were both about 12 feet off of the ground and under an overhang on the side of the house facing east (away from inclement weather).
Smaller unit:
Larger unit:
