Andes: The Walipini is a half underground greenhouse with geothermal energy where it never becomes below 0 degrees [6] Bolivia, Walipini (pit greenhouse) in the high Andes, completely dug pit greenhouse, cross-section [4] Bolivia with the completely dug Walipini pit greenhouse, the view from the outside with the roof opening [15] PVC plastic sheet if very toxic. A transparent roof has tobe of polycarbonat sheets or of glass - with a hail protection. Plastic sheet contaminates the air with plasticizers and microplastics.

Literature
-- James McCullagh: The Solar Greenhouse Book - edition: Rodale press
-- Mike Oehlers: The Earth Sheltered Solar Greenhouse Book
-- Underground Greenhouse: https://insteading.com/blog/underground-greenhouse/

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The invention of approx. 2000: The first pit greenhouse from Bolivia "Walipini" ("Warm Place")

Latin "America": pit greenhouse underground, and on the surface (report from March 2, 2014)
(orig. Spanish: Un invernadero bajo tierra, o en una vieja cuadra)
https://agricultorfindesemana.wordpress.com/2014/02/un-invernadero-bajo-ierra-o--una-vieja-cuadra/

There are two solutions here, one time with a greenhouse dug into the soil completely, and also WITHOUT digging it's working. You just have to build thick earth walls. There are missing raised beds and trenches.

     
Pit greenhouse fully underground, cross section scheme [3] - Pit greenhouse on the surface with earth walls, cross section scheme [4]

Translation:

A few days ago I came across a very good article on the Internet (from ecoosfera.com) where a greenhouse was presented for plantation throughout the year.

The title was "Building a pit greenhouse for growing food all year round" (orig. Spanish: "construye un invernadero bajo tierra para crecer alimento todo el año"). Find the article under this title if you like.

If you think about it, then several advantages are possible with it:

• The earth walls are storing the heat and are releasing the heat into the room
• The cover is not much above the ground level and the winds have no influence on the small construction and on the roof
• In dry climates it is easier to manage such a building, and inside, not pouring is necesary because there is hardly any evaporation.

In addition, I also came up with the idea that this construction can also be used on existing walls if there are old ruins (in villages there are many small plots that have half-crushed houses). So you clear the debris (stones, bars and tiles), make a plastic roof with a wood structure over it and stack a few earth bags on the inner walls. Perhaps there is also a little bit of fertilizer in the ground if the property has served as a stable.

Both versions (the pit greenhouse and the greenhouse o the floor) seem to me to be great ideas for people who live on the countryside. The variations of the building options are in the photo.

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2002: The documentation of the Benson Institute about the Walipini in Bolivia - pdf link  (26 pages)  

Link of the Benson Institute in the Internet archive of 2013: https://web.archive.org/web/20130312233540/http://www.bensoninstitute.org/ (this works)
Here is the link for seing the documentation of the pit greenhouse in Bolivia in the high Andes pdf: link (works)

The documentation of the Benson Institue of 2002 about the Walipini in Bolivia [3]


Bolivia, Walipini (pit greenhouse) in the high Andes, cross-section with roof, walls, door, floor [4]

The walls in the completely sunk Walipini pit greenhouse are inclined
The walls in the cheap Walipini pit greenhouse from Bolivia stay without cladding, but they remain pure earth walls. That is why the earth walls are inclined to the outside so that the earth walls do not "drop" gradually. As a result, the walls have more surface and are storing more heat at the same time as when they were built in a strict 90 degree angle vertical way.

   
Bolivia: Walipini with inclined walls [5] - Example of a simple pit greenhouse in Latin "America" with inclined walls+pitched roof [6]

Since this cheap pit greenhouse house does not have a drainage, a layer of large stones and a layer of gravel was built on the ground, which was then covered with soil.

The gable roof of the second pit greenhouse gets its roof basement by gigantic clay bricks, which are also in an inclined position, exactly at the angle, how the gable roof is constructed.

Details about the roof construction of the completely dug Walipini pit greenhouse

The roof: plastic sheet in the roof section
The roof is a stable double wall polycarbonate construction, but the border regions of the roof are covered with a plastic sheet. This will not last so long, but work force in Bolivia is that cheat so this will not be a problem to replace the plastic sheet all 3 years.

Bolivia: Walipini (pit greenhouse) with rainwater safety system with roof plastic sheets on the floor [7]

The roof: the inclination of the transparent roof to the sun
The blueprint of the totally sunken Walipini greenhouse from Bolivia describes a precise angle of 39 degrees for the sun's position of the winter solstice for the roof. However, practice shows that these exact angles are not so important. But what is really important is the following:
-- The orientation of the inclined roof must be right: it must point to the winter sun and nto to the wrong direction, but an exact angle is not afforded
-- There must be enough earth mass: enough earth walls must be available in relation to the volume
-- The roof must be dense in winter times, also doors and windows
(see the report about the Walipini in Illinois built in 2017 and they needed 3 years until it was freeze free link).

Bolivia, walipini pit greenhouse in the high Andes, the roof has got a 90 degree angle with the winter solstice sun [8]

 
Bolivia, walipini pit greenhouse in the high Andes, summer and winter solstice, scheme [9]

The possibilities of ventilation in the totally sunken Walipini (pit greenhouse)

The completely sunk Walipini: The ventilation
There are various ways to install natural ventilation in a sunken Walipini. At the pit greenhouse from Bolivia, 2 doors crossway were installed.

Bolivia, walipini pit greenhouse in the high Andes, view from above on the salad beds with 2 doors [10]

Belüftung: von Tür zu Tür
Wenn das komplett versenkte Walipini-Grubentreibhaus über 2 Türen verfügt, kann zwischen den beiden Türen etwas Wind entstehen - aber nur falls Wind weht.

Bolivia, walipini pit greenhouse in the high Andes with a ventilation system with two doors in a crossed way [11]

Ventilation: 2 doors and a skylight
If a window is installed exactly between the two doors on a side wall in the roof area, the hot air escapes through the upper window in summer and there is constantly a little wind in the Walipini.

Bolivia: Walipini (pit greenhouse) with ventilation system with 2 doors crossway with air outlet on the upper roof edge [12]


Bolivia with the Walipini, the view from the outside with the roof air outlet [15]

Ventilation with 2 doors and a chimney outlet
A chimney air outlet can increase the draft because the walls of the chimney outlet remain cool in summer, but the air becomes warm.
(According to my opinion, this will not work because the hot air will be trapped at the roof and will not finde the entrance of the chimney).

Bolivia: Walipini (pit greenhouse) with ventilation system with a chemney air outlet (this won't work I think) [13a]

But the following construction could work well when hot air near the roof is racing through a chimney with an open door near the roof:

Bolivia: Walipini (pit greenhouse) with ventilation system with a chemney air outlet at the top of the roof (Modifikation von Michael Palomino) [13b]

Irrigation in the fully sunk Walipini pit greenhouse

Depending on the need, you can set up water barrels in the Walipini pit greenhouse which collect the rainwater for irrigation.

Bolivia, walipini pit greenhouse in the high Andes with rain water barrels and rain gutter system [14]

Unfortunately, the raised beds ("earth tables") are missing here. So you would not have to dig out the entire pit at all, but you could stop at half a height and then only dig the trenches.

Bolivia with the Walipini, the view from the outside with the roof air outlet [15]

This Walipini pit greenhouse from Bolivia is not only always warm, but is also protected from any wind and is therefore absolutely safe from storm.

Only mark it well with colored poles because when there is heavy snow one has to find it again removing the snow from the roof and from the entrances.

This means: this construction with the completely sunk pit greenhouse is only good
-- for regions with little snow fall or
-- being dug into a little slope (step) with a free entrance
-- attached to a dwelling house with an entrance from the dwelling house cellar
-- or you dig a big access with a long ramp which is also accessable during much snow, being marked with a big colored pole.

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A further development of the simple pit greenhouse from Bolivia can be seen here:

2002 appr.: Plan of a pit greenhouse with earth fill on the back wall (article from 2016 appr.)

This plan of a buried Walipini pit cabin with an inclined roof is noticed that the earth walls are twice built, which is actually not needed. The earth bags on the ground wall are superfluous. Here, however, was bricked up with slag, that doesn't really need. But apparently it was the goal of keeping the greenhouse "without earth smell" and even the earth bags are plastered on this plan.
There is luxury with this plan: The earth walls are doubled which is basically not necessary. The earth bags on the walls are not needed. But scoria walls were poured, this is basically not needed. But it seems that the goal was to have a "dust free" greenhouse here and even the earth bags are plastered.

  
Plan of a completely sunk pit greenhouse "without earth smell" [16]
http://alt158.blogspot.com/2014/02/invernadero-bajo-tierra-walipini.html

What is striking with this plan is the following:
-- at the bootom of the door there is a ventilation entry
-- up near the roof there is a ventilation outlet
-- even the floor is plastered with scoria which is really WRONG because the plants growing downwards are blocked.

But the text about this walipini plan is very rich of news because 1) here is indicated that the word "walipini" means "warm place", and 2) here the Benson Institute is mentioned with it's documentation of the Bolivia walipini from 2002. Nowadays (2022) you just have to search a little bit in the Internet archives for finding the old web site of the Benson Institute (link), then you go to the "publications" (link), then you go to the "manuals" (link), and  there is the link to the pdf about the Bolivian walipini ("Walipini Construction (Underground Greenhouse)") Link). Well I have installed this documentation here for you again so you can open it directly here: link (26 pages).


The commenting text of the web site about the plan of the pit greenhouse (translation):

<The Walipinis are a great alternative - efficient and economical - for producing food throughout the year, even in freezy places.

Usually it takes some type of greenhouse for food production in frost areas and for extending certain seasons for longer plantation. The problem with this is that the greenhouses are very expensive with their construction and become even more expensive in winter with heating. A very simple and effective alternative is the Walipini (a word from the Amaymara [Aymara?]-Hindu language which means "a warm place", also known as a pit greenhouse.

It was first developed 20 years ago, for the high frost areas of the mountains in South "America". This method allows the farmers to have a productive garden all year round, even with frost during the cold season.

The incredible of the Walipini is that the principles of warming by the sun can be combined with the earth wall architecture. And the construction is very simple.

In simple words, the Walipini is a rectangular pit that is dug into the ground with a depth of 2 to 3 meters, covered with a plastic tarpaulin. The largest area is the winter sun (in the southern hemisphere to the north, in the northern hemisphere towards the south). A thick, pressed earth wall serves as the back wall, and the wall at the front side [with the window front] is much smaller. This results in the right angle for the plastic roof. This roof now closes the pit and now offers a closed airspace with two plastic sheets. At the same time, the sun rays can pass the plastic roof and thus provoke a constant warm space for plant growth.

The Internet is full of instructions on how to build one, and it is undoubtedly one of the most efficient and most economical buildings for an all-year food production. According to the Benson Institute (which have a guide - link), the costs [in Bolivia] for one one is only between $ 250 and $ 300 dollars.>

(The original link is today (2022) unfortunately dead: http://www.bensoninstitute.org/Publication/Manuals/Walipini.pdf)

Agricultural cultivation during 365 days a year with NO heating: the roof is inclined towards the sun, sunk with all 4 sides   -- The invention of approx. 2000: The first pit greenhouse from Bolivia "Walipini" ("Warm Place")  Latin "America": pit greenhouse underground, and on the surface (report from March 2, 2014) -- 2002: The documentation of the Benson Institute about the Walipini in Bolivia - pdf link  (26 pages)    -- The walls in the completely sunk Walipini pit greenhouse are inclined -- Details about the roof construction of the completely dug Walipini pit greenhouse  The roof: plastic sheet in the roof section -- The roof: the inclination of the transparent roof to the sun -- The possibilities of ventilation in the totally sunken Walipini (pit greenhouse)  The completely sunk Walipini: The ventilation -- Belüftung: von Tür zu Tür -- Ventilation: 2 doors and a skylight -- Ventilation with 2 doors and a chimney outlet -- Irrigation in the fully sunk Walipini pit greenhouse -- A further development of the simple pit greenhouse from Bolivia can be seen here:  2002 appr.: Plan of a pit greenhouse with earth fill on the back wall (article from 2016 appr.)

Photo sources

[1] Pit greenhouse completely underground, cross section, scheme:
https://agricultorfindesemana.wordpress.com/2014/03/02/un-invernadero-bajo-tierra-o-en-una-vieja-cuadra/

[2] Pit greenhouse on the surface with thick earth walls, cross section, scheme:
https://agricultorfindesemana.wordpress.com/2014/03/02/un-invernadero-bajo-tierra-o-en-una-vieja-cuadra/

[4,5, 7-14] Documentation pdf of 2002 about the Walipini pit greenhouse in Bolivia:
Link of the Benson Institute in the Internet archives of 2013: https://web.archive.org/web/20130312233540/http://www.bensoninstitute.org/ (läuft)

[6] Walipini pit greenhouse with earth walls and pitched roof where it's never 0 degree Celsius:
-- www.facebook.com/gmofreeusa - www.gmofreeusa.org
-- im Jahre 2022: https://www.facebook.com/rosanna.silvestro.39 - am 26.10.2021:
https://www.facebook.com/photo/?fbid=10223905585580190&set=basw.AbqJQL3yzyc0kuSGL6WmZs0mKKajgnBWepQn6kL9tAbYAYKyWrRGBg89P4wHaB_CZ3tJC3V3ELdRZPsGtuvTtAE2ldHs3UEdd4gJd8urcp
PyvWcSp7bNpiceyM3a2cI58Qt2SRHUl-Z5zAS-i0NSiazlEHyjYkDJTi8TPWpRBG7jOQ&opaqueCursor=AbpADL5TnM5zOYbZ6THfcfjkQ1RmYYZG9n1JAJXJBjUQDt4Am6jwEFAE4tP-toeEIvRV9ezLG4ZhjCpIehn50NLdCVfoHy-2GDt9yOH-9Bh2-smIa9FGkQhrsM61nEdXY1IQQ-j4fSArdj6HBFIR4vzM_knohK0kSXRlZRquBij8DdtXGCfvA40uMOd7VcqNbF21ezty0eGDle8pfx4x_d9H6zHDqMtevDDyVp8GDfV5u9sO7igzEtuQEFb5RHGqRHpQrL_NvLjJP-qsgdR2YDexVkTEb0hSQNNK7yWutBuVwy-PV1m3job6rMdh4phgDPujXtt9Zlq6a2ob1bP6Y-_K2P9pmMWXhIbY3VKB6W2z0w--3sO0CYJx79sjcRbhJeUTj5BUvRB5Yyk-2W8SUMvZobNC7z0eZmJbxBxTnPn6oMh1KcejJSTtDNOohCVCNNalofqU9fuin0OxnkXg5F9BQrOIu-6jCwu2V3QoG26Ykoq4fSt5ONKZAtETFzu8P2-Nd19e-2oYJFv0_ZH4dL7OGM8p5A1626LccUltNBQ-P--HR7WJg3XRl-t8zYgqQBQ6JpjQduRAy5DIJnVTXOLD8a1kog2_0RWEYxY7VrEUvjMBoYp_IknbZD9xGDIosF4VICHG_YGVtozZJtxMFFkoKyA9yuuNR9g
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F50yqKlXwuHx8XY8C20Fstrtw2UJkZx2Lsaf0At8TPo4RIUoTsEMuHP1JRmp7f3sCI5Rez1VqV-T95NZ44kbyMjQGrXBVk7tN16hV2tRR311qx4pbxpMgwpdPPUw

[16] Plan of a completely sunk pit greenhouse: http://alt158.blogspot.com/2014/02/invernadero-bajo-tierra-walipini.html

             

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