A slice of summer year round.
For those of us who live in cooler parts of the world, a reprieve from harsh winters can be much needed. But rather than travel hundreds of miles for a brief few days of warmth and sunlight, what if we could build a little semi-tropical room of our own? What would you do with a toasty studio or place for your underground band to play? Enter: the walipini.
According to the Inspiration Green website it's “Called a walipini in South America (from the Aymara Indian language, meaning "place of warmth").” - See more here. Some sources say these structures are typically 50 to 60 degrees Fahrenheit or warmer even in the dead of winter.
The walipini is essentially a greenhouse sunk six to eight feet into the earth (depending on water table) with a side or roof at a ninety degree angle to the sun. It employs plastic or glass windows using passive solar rays to heat the interior. It is recommended to use rock or even barrels of water as a sort of thermal battery to continue warming the room through the cool of the night. Some folks are even using a rocket mass heater which burns anything and can store thermal energy for 12 to 24 hours. More on those here.
You may be thinking this sounds expensive. I does not have to be at all. In fact a small walipini could be dug out and built in a weekend with a few strong helpers and the right supplies. The earth is really the bulk of the structure. At Treehugger.com they seem to have put one together for under $300! http://www.treehugger.com/green-architecture/build-underground-greenhouse-garden-year-round.html
There are many uses, the most common growing food supplies in harsher climes. Using this design we can eek out a few more weeks or even months of fresh from the garden foods. Rather than harvesting twenty tomato plants and canning or trashing excess, why not plant four and simply harvest fresh tomatoes longer?Alternatively, this space can be used as a winter retreat. In this part of the world, hot summer days only last a few months of the year. This could be a sunny solution to dreary winter months. Build a sunken patio or sun room for winter fun. Run a rocket mass heater for a little extra temperature boost and we could even have those citrus and avacado plants we've always wanted. The acoustics must be spectacular for playing or listening to music!