guildfordcycads

What could I get away with planting now in a hot dry zone 10 Mediterranean climate? Would it be a waste of time and energy to try and plant any young fruit trees or support species?

There’s lots of natural building styles, and it seems many can be done in many places. Some are more suited for a region than others, and I feel this angle can sometimes be glossed over or compensated for with industrial inputs like stabilizers and additives.

I am interested in what methods are not only ideal for a region, but can be perpetuated in a low-energy, post-industrial future. So while everything from earthbags and hyperadobe, to strawbales, to earthships is interesting to me, I want to learn something that can be taught and passed down, and will still be being replicated 100 years from now. Or at least, a modern method with transference to a similar historical vernacular building technique.

With that in mind, here is the research I have done on natural building for my region. Hoping others can weigh in on it and add any corrections or their own thoughts.

First, looking at global climate zones. It seems the Southeast US is actually fairly unique as far as how extensive our Humid Subtropical zone is. This is due to the AMOC circulation, which is weakening, so we may actually become more temperate in a warming world, or it will even balance out. But I digress.

https://en.wikipedia.org/wiki/Humid_subtropical_climate#/media/File:Koppen_World_Map_Cwa_Cfa.png

https://amocscenarios.org/

Second, looking at what the indigenous were doing in our region. It seems we have an even split along the Piedmont, with Creek and Cherokee cultures doing wattle and daub with thatched roofs, and Powhatan culture doing rounded wood longhouses.

https://images.app.goo.gl/GRsXWMdyz63aA932A

Concerningly, this may track with the Coastal Plain to Piedmont transition, and may be telling about what soil type is available per method? Like, maybe the greater sand to clay ratio of the Atlantic Plain is what makes daubing possible? But it only seems like a partial and probably coincidental overlap, and I know that outside the Coastal Plain they were still doing wattle and daub, such as in the Appalachian mountains.

https://images.app.goo.gl/zCumeBNJPkQ1e3ka7

So lastly, taking all this into account, we can look at other cultures around the world for inspiration within the Cfa climate zone.

Assuming that wattle and daub with thatched roofing is a technique reflective of the nomadic or semi-nomadic lifestyles of the Creek and Cherokee peoples, and that a sedentary, fully settled populace would need to develop more permanent styles of natural building, I think the Hmong people of North Vietnam, and Hakka people of Southeast China, are both good candidates for what could be done in our region. The Hmong and Hakka both make extensive use of Rammed Earth for their natural buildings. Both build with similar materials, with examples that have lasted many hundreds of years, keeping cool in summer and warm in winter while surviving extreme weather events. They both use rammed earth walls, natural stone foundations (usually limestone?), structural timber, and clay tiles for roofing.

A tulou is usually a large, enclosed and fortified earth building, most commonly rectangular or circular in configuration, with very thick load-bearing rammed earth walls between three and five stories high and housing up to 800 people. Smaller interior buildings are often enclosed by these huge peripheral walls which can contain halls, storehouses, wells and living areas, the whole structure resembling a small fortified city.[3]

The fortified outer structures are formed by compacting earth, mixed with stone, bamboo, wood and other readily available materials to form walls up to 6 feet (1.8 m) thick. Branches, strips of wood and bamboo chips are often laid in the wall as additional reinforcement. The result is a well-lit, well-ventilated, windproof and earthquake-proof building that is warm in winter and cool in summer.[3] Tulous usually have only one main gate, guarded by 4–5-inch-thick (100–130 mm) wooden doors reinforced with an outer shell of iron plate. The top level of these earth buildings has gun holes for defensive purposes.

I think the Hmong “Trinh tuong” houses make the most sense for an individual or single family to emulate, but the Hakka’s Fujian Tulous are very interesting for any groups and may be the more common arrangement for future generations, given societal stresses from declining global energy returns and climate change causing a re-emphasis on communal and mutualistic living.

Hmong:

1. https://en.vietnamplus.vn/rammed-earth-houses-a-cultural-heritage-of-hmong-people-in-ha-giang-post312255.vnp

2. https://en.vietnamplus.vn/nung-ethnic-hamlet-attracts-tourists-with-traditional-rammed-earth-houses-post280290.vnp

3. https://en.vietnamplus.vn/rammed-earth-houses-unique-architectural-identity-of-ha-nhi-people-post188713.vnp

4. https://www.vietnam.vn/en/kien-truc-nha-trinh-tuong-mai-am-duong-cua-nguoi-dao-tien-o-cao-bang

5. https://en.wikipedia.org/wiki/Hmong_people#/media/File:HouseBuildingInNorthernVietnam.jpg

Hakka:

1. https://en.wikipedia.org/wiki/Fujian_tulou#Architecture

2. https://whc.unesco.org/en/list/1113/

3. https://www.chinahighlights.com/xiamen/attraction/tulou.htm

Here are some more in depth overviews of the Fujian Tulou traditional building techniques:

1. (PDF link in text) https://www.sciencedirect.com/science/article/pii/S2351978920307952

2. https://www.sensesatlas.com/fujian-tulou-the-hakka-walled-villages/

3. https://archeyes.com/fujian-tulou-the-resilient-and-communal-hakka-walled-villages/

4. https://www.mdpi.com/2075-5309/14/7/1915

Some ideas for alternatives:

1a) It seems the limestone foundation is to protect against flooding and water resting against the rammed earth walls, which is about the only thing that would degrade them, and could render them unstable quite quickly. With proper permaculture site design and drainage techniques, perhaps this risk could be mitigated and the rammed earth portion could extend down to the ground? A migrating people group can intentionally move next to a river or potential quarry site with lots of suitable stones, private landowners have less options.

1b) If not, or in addition to this, could one use wood ash in the firing process for low-fired clay bricks to make them waterproof, and use that as the foundation? I am pretty sure he essentially makes roman concrete or fly bricks here.

https://www.youtube.com/watch?v=DP0t2MmOMEA

https://www.youtube.com/watch?v=rG6nzrksbPQ

Or even: https://www.youtube.com/watch?v=9irICRnszOc

2) I wonder if bamboo could be used structurally in place of some of the internal timbers? Either group probably would have tried that if it was viable, but perhaps (without looking into range maps) they didn’t have access to the right species for construction. Even if the beams and columns would still need to be wood, I wonder if the rafters and purlins for the roof could be made of bamboo. From reading some old permies threads on it, it seems bamboo can be made (with a long soak in water) to be as or more rot resistant and strong when compared to oak. Pine seems to be the wood of choice for the Tulou at least, so this could maybe be an upgrade?

https://permies.com/t/56799/build-bamboo

3) Likewise, the Hmong “Trinh tuong” house pictures have examples of both thatched and clay tiled roofs that have essentially become living roofs, with moss growing on them. I’m imagining this adds to the insulation and increases resistance to weathering, though could be wrong and it lead to poor water shedding or otherwise be undesirable. Could this be intentionally cultivated, whether with moss or another species that gives an edible yield?

4) The above 4. Hmong section contains some of the apparent issues with their style of housing (that may just be lack of maintenance, hard to tell). I think the Tulou design, being open to the inside and with high windows for cross-ventilation, may address these. If one was building a single house, it’s possible you could replicate this with a ‘mini-Tulou’ that is made courtyard house style, with a thick perimeter wall, 2-4 internal buildings/rooms, and a large open-air middle.

https://en.wikipedia.org/wiki/Courtyard_house

5) Lastly, rammed earth is obviously quite labor intensive. For a village coming together, this is no big deal, but not so for an individual or small family (especially if wage labor takes up the majority of ones time). In terms of modern methods, what style would be best to replicate similar outcomes and some transferable skill learning as rammed earth? I am guessing hyperadobe here, and perhaps reclaimed sheet metal for the roof. Skillwise, one would still have to learn to make the forms and the tamping process for rammed earth, making and firing the clay tiles, and working with roundwood for the framing. But the outcome would at least be similar and give one an idea to go off of while slowly picking up the ‘real thing’ on the side, to be able to teach and pass to others.

Hopefully this is helpful to someone! Any thoughts are appreciated. 🙂