From Collin's dad's solar geodesic greenhouse, through a greenhouse built from soda bottles, to a simple DIY hoop house, we're not shot on self-built grow spaces here on TreeHugger. but the Permaculture Research Institute of Australia has a very detailed post and time-lapse slideshow by Rob Avis about how he built a passive-solar greenhouse in Calgary. Interestingly, he says, the European model of greenhouse was designed for low levels of mostly diffuse light in winter. Calgary is, according to Avis, better suited to a passive solar structure that maximizes direct sunlight from the South, while preventing heat loss through heavy insulation on the North side. How does it work? We don't know because he is yet to grow anything. But it sure looks good.