I whipped together a two story birdhouse for our garden out of scrap pine I had left over from a cabinet project I started and never finished. Before we moved to our new house about 6 months ago, we had a successful birdhouse on the back of our old house that my youngest son had made me for Father's Day a few years back.
He was sad that we had to leave it behind, but I explained to him that the birds would return again next year and their house would be gone. So, we left it behind in the hopes that the new owners would also leave it up there.
My son missed having the birds to watch so I made a new unit for our new house. But this time, I wanted to make two small houses out of one. We haven't had anything take up residence yet, but then, it took about a year for the last one to work out either. So, here's hoping.