Earth-formed : Earth-sheltered Building
provision of living quarters for oneself and one's family demands more
time and effort than perhaps any other necessity of life. This new
of construction can provide more than just shelter. Clean water, fresh
produce, cost-free warmth and cooling, and increasingly important
protection from extreme natural and social disruptions are possible
contributions of its design. Persons strong in body can
manually hand-build their own homes with minimal instruction, and with much less expenditure
of energy and materials than required by standard construction.
The Liberty Home method uses structurally optimized arched and domed shapes formed by sculpting the earth on location, then pouring or shooting concrete over the form, casting a relatively thin monolithic shell. The earthen forms can be carved either by hand or with equipment depending on circumstances and size. Little or no wooden, metal, or expensive inflatable membrane form-work is required. All pouring and/or shot-crete work is performed safely on the exterior of the form, not from underneath as some thin-shell concrete methods require. Working with gravity, not against it is safer, faster, easier and less costly.
Creating an easily placed insulating and moisture-proofing umbrella over, and extending beyond the perimeter of the entire structure, eliminates the need for insulation of all walls, ceilings, and floors. This is avoided since the natural dynamics of this method take great advantage of absorption of heat through the walls in summertime, and storing it in the protected huge earthen bank surrounding the structure. In the wintertime the btu's then move back through the walls and into the cooler living spaces. This happens spontaneously, and at no cost and maintenance year after year.
In the summer time, the
direction of the heat flow naturally reverses. This insulating
umbrella concept allows for non-uniform,
irregular, free-form design without the limitations is design usually required for
insulation from moisture and heat.
This greenhouse's bell-shape aerodynamically aids air circulation and convection into the house when desired. The latest models are designed to actually generate some electricity from the convection of warm air, gaining in velocity as it rises through the decreasing volume under the the bell-shaped glazing. The central windowed "goblet" serves several functions, including water distillation, water-heating, variable hued lighting, humidity regulation and use of other low-tech, natural principles.
A Liberty Home (and other-use structures) are formed in the earth, using mounded and sculpted earth as a reverse mold as illustrated in this animation. Shot-crete or poured Portland cement mix is applied over the earthen hemi-spherical mound. After setting and curing of the concrete, the soil is removed from under the reinforced shell and placed on top of it. More earth is then bermed over the structure. Then the shelter and surrounding earth bank is covered with an umbrella comprised of several alternating layers of insulation and polyethylene sheeting, extending beyond the perimeter of the structure 20'. The insulating, water-shedding, 'umbrella' itself is then covered with more earth sufficient to adequately support growth of vegetation for ground-cover.
If heavy equipment is not available or affordable, it is feasible that the entire form can be hand-sculpted with only a shovel and other hand tools. It is surprising how much dirt can be moved by one healthy person in a short period of time. .. or even by an aging, out-of-shape codger such as myself. The reverse mold for my 20' diameter model was created in only twelve hours of hand-digging with a spade. A design including several such intersecting domes instead of a single, larger diameter dome, still makes hand-digging of multiple-roomed structures possible.
A small 'Bob-Cat' type back-hoe/front-end loader or excavator, a powered conveyor belt, or for larger buildings, larger earth moving equipment, obviously can get the job done much quicker and with less muscle power.
Many circumstances in the near future will prove labor-intensive activity of positive benefit, rather than a burden. Otherwise unemployed persons can build their own homes...and help others build theirs. There are few localities with soil structure or water-table issues where provisions cannot be worked around to allow such a structure to be built. Earth formed, sheltered buildings can be constructed completely above ground by mounding earth (and other) materials for use as a form, and then bermed over with earth. They can be designed to be built partially below grade and partially above ... or completely underground.
The greatest negative now is the requirement for Portland Cement and iron reinforcement materials such as rebar and welded wire mesh. These materials are costly in terms of the environment and the huge CO2 emissions involved in manufacturing and transportation. Someday soon, hopefully both of these materials too can be replaced with structurally safe, and less environmentally harmful and local materials.
Considering the low maintenance and incredible life-span of these structures, the environmental costs amortized over the long-term are probably less, even now, than those for standard construction methods and materials. Until other ways are perfected to support the weight of the soil, to the author, a real necessity for the days ahead, using concrete may be the only safe way to build underground or earth bermed structures.
(09/2008) I am presently hopeful about the recent developments in passing CO2 from the atmosphere and power plant smoke stacks, through sea water to produce a calcium magnesium cement, similar to the biological creation of shells and corals. The day may soon arrive when building with concrete structures will be used to sequester excess carbon we have already placed in the air by burning fossil fuels. My reservations are turning into excitement again. If the concrete already being produced can be made as hard as clam shells perhaps we can do without the rebar altogether. Now that would be great, would it not?
And the second material, iron, used for reinforcement, now appears to be surpassed in many ways by the production and sale of basalt (lava) products, many times lighter and stronger than iron. This makes building domes a whole lot easier and faster, with no deterioration of the shell by rust or different coefficients of expansion and contraction between concrete and the reinforcement.
Earth-forming can be used to create buildings of any size and most any purpose. The method particularly lends itself to inexpensive storm shelters and emergency protection from many catastrophic circumstances, including nuclear blast and fall out. (Three feet of earth will reduce the amount of gamma radiation 1000 times over an unprotected area.) This and other benefits result from berming the finished shell with bermed earth.
The buildings can be built underground, undetectable to passers-by. Entire communities can be designed, with environment friendly structures for shops, common areas, emergency shelters, workshops, and storage facilities. The structures can be well lighted, and ventilated ... artistically designed , satisfying and pleasing to the eye, and made to blend harmoniously with the environment. 'Underground' does not necessarily mean cave-like. From root-cellars, saunas, special livestock shelters, from plain-domed shapes to free-form sculpted rooms ... shopping malls? churches? all earth-formed and earth-sheltered at lowest cost available.
"Dirt-cheap" housing, healthful, comfortable, and aesthetically pleasing should be a reality for anyone who needs and desires it. Gifts from the Creator: Earth, the Sun and all the laws of nature, available for the responsible use and taking. All other creatures seem to have accomplished this. Why can't we humans?
Being earth sheltered, storms can blow, temperature records broken, earthquakes can shake, fires rage. This may be the safest place to sleep and live in the chaotic days ahead, not just for emergency shelter. With the use of simple, age-proven principles, there may still be life left to carry on, and still standing structures to use in the new start.
My first hand-dug, earth-sculpted
'form' for a 20' dia room took only
12-hours to dig
SketchUp model of a Liberty House design I am working on
Thanks for your interest Gerald Brittell