Jim Shields mentioned the impossibility of maintaining an alpine house in central Indiana. I remember a book, written perhaps in the 1940s or 50s, about using a "pit greenhouse", dug into the earth, with steps leading down to a central aisle in which one stood. The "benches" were undug soil with the plants set on top, and a glass roof covered it all. There were probably openings for ventilation, but I don't remember the details. The insulating effect of the soil prevented overheating in summer as well as retaining heat in winter. The almost-at-ground-level glass would have been easy to shade in summer - I think I would just grow cucumbers or pole beans on the sunny side. There is a website that has a summary of solar greenhouse information since many of the books on the topic are out of print. http://attra.ncat.org/attra-pub/solar-gh.html Perhaps this would not be sufficient for an area that has hot humid summers. I attended a talk by an Eastern North American speaker who had an air-conditioned alpine house. -- Diane Whitehead Victoria, British Columbia, Canada maritime zone 8 cool mediterranean climate (dry summer, rainy winter - 68 cm annually) sandy soil