I was chatting with my family online this evening and my sister mentioned an underground greenhouse. Intrigued, I followed the link she posted to an article at treehugger.
The Benson Institute developed the plans for the walipini or "place of warmth" as a way for families in La Paz, Bolivia, to garden throughout the year, despite the intensely cold mountain winters. The plans for the 20’ x 74’ greenhouse requires roughly $250-$300 in materials, assuming free labor and no need for heavy equipment. The Walipini manual indicates you'll want about 100 square feet of growing area to feed a person year round.
The basic walipini plans could be further enhanced to include subterranean heating and cooling, since there is already significant sub-floor work involved to ensure adequate drainage. The plans also mention the benefit of incorporating water barrels to store heat energy. In my research associated with this article, I learned (or re-learned?) that water holds four times as much heat energy per unit volume as concrete. So using water to store heat energy is more effective than a trombe wall. And if the water you are storing is also irrigating your plants and providing a habitat for fish, all the better!
By the way, my book on Aquaponic Gardening will be available in less than a month. Very exciting! And I just saw the cover for the first time:
Pretty and green!