Build a $300 underground greenhouse for year-round gardening

[Serpo]

Build a $300 underground greenhouse for year-round gardening (Video)

http://media.treehugger.com/profiles/bio-2011-km.jpg.50x50_q100_crop-smart.jpg (http://www.treehugger.com/author/kimberley-mok/)
Kimberley Mok (http://www.treehugger.com/author/kimberley-mok/)
Design (http://www.treehugger.com/design/) / Green Architecture (http://www.treehugger.com/green-architecture/)
February 22, 2013


http://media.treehugger.com/assets/images/2013/02/walipini-2.jpg.492x0_q85_crop-smart.jpg
© Neo-farms (http://neo-farms.com/wp-content/uploads/2012/07/walipini-2.png)
Growers in colder climates often utilize various approaches to extend the growing season or to give their crops a boost, whether it's coldframes (http://www.treehugger.com/green-architecture/jenny-sabin-futuristic-greenhouse-uses-110-laser-cut-coldframes.html), hoop houses (http://www.treehugger.com/lawn-garden/build-your-own-mini-hoop-house-in-hours-video.html) or greenhouses.
Greenhouses are usually glazed structures, but are typically expensive to construct and heat throughout the winter. A much more affordable and effective alternative to glass greenhouses is the walipini (an Aymara Indian word for a "place of warmth"), also known as an underground or pit greenhouse. First developed over 20 years ago for the cold mountainous regions of South America, this method allows growers to maintain a productive garden year-round, even in the coldest of climates.
Here's a video tour of a walipini that even incorporates a bit of interior space for goats:
How a Walipini works and how to build one

http://media.treehugger.com/assets/images/2013/02/walipini3.jpg.492x0_q85_crop-smart.jpg
© Benson InstituteIt's a pretty intriguing set-up that combines the principles of passive solar heating with earth-sheltered building. But how to make one?From American sustainable agriculture non-profit Benson Institute comes this enlightening manual on how a walipini works, and how to build it:
The Walipini utilizes nature’s resources to provide a warm, stable, well-lit environment for year-round vegetable production. Locating the growing area 6’- 8’ underground and capturing and storing daytime solar radiation are the most important principles in building a successful Walipini.
The Walipini, in simplest terms, is a rectangular hole in the ground 6 ‛ to 8’ deep covered by plastic sheeting. The longest area of the rectangle faces the winter sun -- to the north in the Southern Hemisphere and to the south in the Northern Hemisphere. A thick wall of rammed earth at the back of the building and a much lower wall at the front provide the needed angle for the plastic sheet roof. This roof seals the hole, provides an insulating airspace between the two layers of plastic (a sheet on the top and another on the bottom of the roof/poles) and allows the sun's rays to penetrate creating a warm, stable environment for plant growth.

http://media.treehugger.com/assets/images/2013/02/walipini.jpeg.492x0_q85_crop-smart.jpg
SilverThunder (http://peswiki.com/index.php/User:SilverThunder)/via
This earth-sheltered greenhouse taps into the thermal mass (https://en.wikipedia.org/wiki/Thermal_mass) of the earth, so that much less energy is needed to heat up the walipini's interior than an aboveground greenhouse. Of course, there are precautions to take in waterproofing, drainage and ventilating the walipini, while aligning it properly to the sun -- which the manual covers in detail.
Best of all, according to the Benson Institute, their 20-foot by 74-foot walipni field model out in La Paz cost around $250 to $300 only, thanks to the use of free labour provided by owners and neighbours, and the use of cheaper materials like plastic ultraviolet (UV) protective sheeting and PVC piping.
Cheap but effective, the underground greenhouse is a great way for growers to produce food year-round in colder climates. More over at the Benson Institute (http://www.bensoninstitute.org/Publication/Manuals/Walipini.pdf) and the Pure Energy Systems Wiki (http://peswiki.com/index.php/Directory:Walipini_Underground_Greenhouses).


http://www.treehugger.com/green-architecture/build-underground-greenhouse-garden-year-round.html<a href="http://www.treehugger.com/green-architecture/build-underground-greenhouse-garden-year-round.html" target="_blank">
http://www.youtube.com/watch?v=qB8AE_H_YTc (http://www.treehugger.com/green-architecture/build-underground-greenhouse-garden-year-round.html)http://www.youtube.com/watch?v=qB8AE_H_YTc

[Awoke]

One decent Canadian snowfall and that pup tent would cave right in.

[Son-of-Liberty]

It's a good idea but like awoke said that design is not built for heavy snow. I saw TV show ears ago where a Chinese guy had modified a regular greenhouse, can't remember exactly what he did now. The just of the show was that he was growing tomatoes in Manitoba in the middle of winter and using no external heating. The guy said that is how they did it in China.

[Libertytree]

Seems like you could swap the wood on the slant for steel and the plastic for plexiglass.

[gunDriller]

One decent Canadian snowfall and that pup tent would cave right in.

i was thoughtless on this subject last year. i had a 16x20 'heavy duty' tarp tied in about 7 places. then it got just about an inch of wet snow.

my porch tarp brackets held. but the railing didn't. it ripped off. no big deal, now i can improve the design :)


but a lot of locations that get the snow, also have the sun at an angle, so the clear surface facing the sun can be slanted at 45 degrees and still get a lot of light energy but it takes a really deep snow.

[Serpo]

Yea well this is a basic concept which could be altered for different areas

[Libertytree]

This is one of the best basic designs I've seen and if built on higher ground with footers poured inside and out with a proper glass roof it could be very liveable, especially with a fire place.

[Son-of-Liberty]

I do like the basic idea behind the design. Very good for extremely cold climates.