I’d imagine you’ve seen a variety of greenhouse designs, including the traditional hoop house styles, but have you ever seen a Walipini? It’s purposely designed like this to more efficiently transfer heat in the winter, reduce heat in the summer, and even water the grow beds too. Of course, there’s some math involved, but nothing most of us can’t handle. He starts to talk about the idea at the 2:30 mark using a helpful diagram and then later tours us through his own Walipini several minutes in. Personally, I wonder if it’s worth the effort, at least when compared to a hoop house, but it could work out well in the right circumstances.