by Pratik Zaveri and Rachel Preston Prinz
One of the most difficult aspects of talking about the
Earthships is addressing issues around the data presented as supporting
evidence for the idea. The Earthship website and publications are a bit “fuzzy”
and we want to clarify what we can so our readers can have solid information
when making decisions regarding a potential Earthship home.
We call some of what happens in the Earthship books,
website, and philosophy a “One-Way View.” Without realizing it, the literature
points to reasons to use the model… that actually point to problems with the
model. We have touched on some of these already. Earthship Volume 1 and
the Earthship website both talk about indigenous materials being available
around the world and then go on to point out that shipping materials great
distances uses a lot energy and is therefore not sustainable. This statement,
while looking towards an ideal that we all really want to meet, fails to
address the economic and energetic inputs required to obtain and transport the
materials required to build an Earthship, as we identified in The Myth of “The
Most Economical Building Design in the World” section. It forgets that
Earthships require triple or quadruple the energetic inputs of a standard
building. It only sees what it wants to see – the ideal. This is a perfect
example of a “one-way view” and it is based on a concept called “cognitive
anchoring”. From Wikipedia:
“Anchoring or focalism is a cognitive bias that
describes the common human tendency to rely too heavily on the first piece of
information offered (the "anchor") when making decisions. During
decision-making, anchoring occurs when individuals use an initial piece of
information to make subsequent judgments. Once an anchor is set, other
judgments are made by adjusting away from that anchor, and there is a bias
toward interpreting other information around the anchor. For example, the
initial price offered for a used car sets the standard for the rest of the
negotiations, so that prices lower than the initial price seem more reasonable
even if they are still higher than what the car is really worth.”
The many issues of not depending on traditional systems
that the Earthship literature attempts to address are absolutely valid, as
every day we seem to get nearer to an economic and cultural collapse that
renders alternates not only ideal but necessary. However, the “better world”
the Earthship ideal promises cannot be delivered through ideals and wishful
thinking. It has to come from actions… and those actions need to be based on
good science and good design.
Underlying Science
Especially in Earthship Volume 1, solid science is used to understand the movement of the sun
and other natural processes. Yet, some of the most important details that could
help builders to make the design more successful are omitted. For instance,
soil is mentioned only briefly, stating the
Earthships “must be built on undisturbed earth”, and yet, to build them, we
disturb the earth. There is also no mention that thermal performance is degraded when the soil used in the berm is naturally wet, or that the Earthship needs
extra design consideration when the inner-earth temperature is lower than that of Taos. This inner-earth
temperature issue has led to critical issues in Earthships around the world.
Let’s look at this a little more deeply.
The Earthship website points out that the Earthship’s
technology is based on the sun, the earth, and the efforts of the people
themselves. That is sortof true. The passive solar
aspects of the design and the photovoltaics
use the sun. There is earth in the berm. People build the Earthships.
Earthships also use a huge number of solar panels, batteries full of toxic
acids, and countless manufactured goods, many of which have extremely high
embodied energy
equal to and even well beyond that of standard
buildings. As well, sophisticated engineering skills are required to design,
install, and maintain the Earthship so that the technologies can work.
So
the ideal is really based on simple natural AND complex manufactured processes.
Affordability and Do-ability
The ideal is that the Earthship is financially accessible
by the common person, but experience does not bear that out, as we have
illustrated previously in The Myth of “The Most Economical Building Design in
the World” section.
It is stated in the Earthship literature that the
Earthships are specifically designed with the intent of being built by
unskilled people. While the methods
of construction may not necessarily require skill, they most definitely require
ability. Pounding tires is not for
the faint of heart and building angled walls is really only work for a master carpenter. This
is one reason why you may really want to consider using Earthship Biotecture’s
teams to build your home if you can afford them - they are second to none in
these skills.
The Earthship books stress the importance of orientation towards the sun, but neglect that orientation
is only relevant when you live in a place with ample sunshine. Cloudy days,
which are not mentioned at all, can render the Earthship just another failed
building, as we will see in Chapter 2.
Earthship Volume 1 talks about facing the Earthship
north in Taos. How would a north-facing design even work? It would be a snow magnet and would hold ice and snow against the
house when it needs to be in the sun to melt! Sure, large north windows are not unusual in Taos… when the artists
arrived they wanted that pure north light so they built huge windows facing
north… but these were not used in Taos until the late 1800s, because in order
to pull off a completely nature-ignorant design, you needed a large wood stove to compensate for the cold north wind. The books do not address
this needed heat source. The book goes on to propose a roof garden, in an area with a 140 day growing
season, high winds, and tendency for drought. This is not the recipe I would
follow for a house in Taos. Evidently, they figured out not to do that as well,
because the Taos Earthships face south and there are no rooftop gardens that we
know of.
The wind diagrams in the book show wind coming from one
direction, and it looks like it is usually assumed as from the south. The
problem is… the wind in Taos comes from the North in winter and West in summer.
Showing it coming from a direction it rarely does suggests that the ventilation will not work effectively. The research and commentaries from users indicates that
this is accurate - many Earthships have ventilation issues, especially those
where predominant winds come from less than ideal directions for the design.
For the greenhouse’s low awning windows to functionally draw air into the space and up
through the skylight there has to be some wind pushing into and
away from the building from the right directions to force enough draw.
Materials of Construction
The Earthship website’s Construction Materials page talks
about how for the vast majority of human existence, our homes were built of
found indigenous materials including stone, earth, sticks, and grasses. That
is true. But unlike tires, concrete, aluminum cans, and glass bottles… stone, earth, sticks, and
grasses have extremely low embodied energy, as they can be found at just
about any good potential building site. To add to that, the embodied
energy of concrete, which makes up roughly half of the building materials used
by volume in a modern Earthship’s construction, is staggering. (Refer to the Concrete section for more information.) Concrete is not
a by-product of our civilization. It is a mined product that rapes the
environment and diminishes our ability to breathe.
Indigenous is typically understood to refer to locally-sourced,
raw materials, or local peoples. Indigenous is the epitome of simplicity.
Tires, concrete, bottles, and cans are not simple, nor are they indigenous to
anyone’s site that we
know of. Shipping tires, concrete, cans, and bottles from wherever they
are to your build site uses energy and removes these materials from the
recycling stream. These misconceptions help to illustrate why Earthships are
not truly sustainable.
The literature talks about wood being less than ideal as a durable material
for building, as it is natural, lightweight, and porous, which will lead it to
decompose quickly. The people of Bavaria, who have lived in some of their
wooden houses for 400 years, may disagree with that. As would the builders of
the Hōryū-ji temple pagoda in Japan, which still stands after the wood was
felled in 594AD! That is nearly 1,500 years old! Wood can last a long time when
it is felled at the correct time, is the right species for its use, and is well
cared for over its life. And not all wood is light and porous. Generally, we
use heavy and dense deciduous hardwoods on the exterior of a building and evergreen
softwoods for interior framing. Plus, to be fair… Earthships use a boatload of
wood.
The literature goes on to complain that manufactured
materials dictate the way buildings are built, and then goes on to suggest that
the reverse should be true, implying that housing should dictate the nature of
materials. And yet the primary building block of an Earthship is the tire – a
highly manufactured material.
What the Earthship literature offers as a means of explaining
embodied energy is not a complete picture of what embodied
energy is. Embodied energy is the amount of energy it takes to take a raw
material, get it to a manufacturing site, manufacture the finished
product, and then get it to you. Embodied energy can be high – aluminum, a
common component of solar panel installations as well as an Earthship’s can
walls, contains an enormous amount
of embodied energy – it has to be mined, to the tune of 8 tons of ore per 1 ton
of usable material; shipped great distances for manufacturing; designed; then
takes a great deal of heat to produce a usable product – which also means a
great deal of fuel; then it must be shipped to a warehouse, to the supplier, and
then to the build site. Whether that aluminum is in a reused can or a brand new
window, it still had to have all of those processes applied to it. There IS
embodied energy in an Earthship. Just because we are reusing the embodied
energy required does not negate its existence. In fact, the reality here is
that reusing cans in walls
requires more materials to be mined and manufactured because the
first-generation cans are being removed from the recycling stream.
The literature also states that one of the main goals of
the Earthship ideal is to use materials that require little or no manufactured
energy. And yet, the building blocks
of Earthships… the tires, cans, bottles, concrete, wood framing and vigas, roofing, cooling tubes, insulation and thermal wrap, cisterns, interior finishes, glazing
for two walls of windows, shades, glass doors, appliances, and the mechanical and plumbing systems… have manufactured or embodied energy… and lots of it.
The literature makes the case that the Earthship is using
such simple materials that it makes sense for large-scale production for
low-impact living. Except, large scale production of the currently extremely
oversized Earthships is not sustainable.
Earthships have gigantic footprints, in terms of the amount of land required to build on, as well as square
footage, as well as embodied energy. They are also too expensive
to be viable for large scale development.
The literature goes on to discuss the ideal of not relying
on natural gas, but many Earthships at latitudes above and including Taos have
been retrofitted with propane or gas to stay warm enough in winter.
The importance of not relying on modern food systems is discussed, yet the food growing
system as designed most often cannot provide the quantity of food that makes
self-reliance possible. What is offered is an extraordinarily expensive system
that cannot provide in grocery savings what it adds in cost.
Systems
The literature speaks to the common house using “monstrous
systems” and states that the modern house cannot function without systems. Reynolds
likened the standard home and its large systems to being a patient in ICU being
“plugged in” at a hospital: If the lines were cut, then what?
Yet, nothing is ever mentioned of the standard systems used
in an Earthship, which deplete resources, cost a great deal at outset, are prohibitively
complex to maintain and repair, and still do not work when something goes wrong.
All of this costs money and resources. To compound that, backup heat and power
are required in nearly every build because most Earthships do not work as
intended. Systems are a reality for the vast majority of owners.
The literature goes on to discuss the Earthship in relation
to a car, addressing the very real concern that reliance on cars
is part of what is wrong with sustainability
in our world. Yet, Earthships are often located out in the distant expanses and
do not work as intended, forcing users to depend on a car far more than the
average homeowner – to get materials, water, groceries, gas, to get the kids to
school - and, because they are “out there” where it is legal to build experiments,
oftentimes owners must travel further distances to do these things. My grocery
store is 2 miles from my home. I travel four miles total to get down to the
store and back. Greater World is 15 or so miles from the grocery store. That is
30 miles total. Even if we both only need a carton of milk, my cost
and time investment is dramatically lower.
Multiply that mileage times 40 trips to the store a year.
Now
multiple it by the number of trips into town you must make to get supplies, get
water, take the kids back and forth to school…
Saving the Rainforests and Oxygen
The literature notes that when we cut down the rainforests,
we cut off our own oxygen supply. This is such an important issue and that fact
cannot be argued. The first book goes on to imply that Earthships are minimizing
the impact on deforestation to resolve this issue. However, Earthships use huge
amounts of wood, which results in forests being cut down. Is
this ideal really being met here?
Earthships also use as much or more concrete as that used
in a traditionally constructed home. Concrete uses oxygen to cure over its life and it gets
that oxygen from the air we breathe. The manufacture of the Portland cement used
in concrete contributes to between 5 and 10% of the world’s greenhouse gases.
So,
in principle the Earthships are saving the rainforests, while in practice they are
making them work harder.
Impacts on the Water System
The literature addresses the issues of the global water
supply and its impact on the ecosystems that affect fish. This concern is justified,
as we continue to poison our oceans with untold numbers of toxins. Yet, the leeching of the tires and the septic systems in an Earthship build has the
potential to affect the health of the aquifers from which we all drink. A
common admonishment in the professional and academic tire research is that the places we store tires are supposed
to be isolated from any contact with the water supply via sealed EPDM pond liners.
The commonly held belief that Earthships are comfortable is
supported by the Earthship literature stating that the temperature ranges from
65-76 degrees with no backup heating or cooling. This is just not accurate,
as we have described in the Myth of Thermal Comfort section.
The Thermal Mass section of the Earthship website states
that a lightly-built house (presumably one without earth-sheltering) “obviously” takes more
energy to heat and cool. Only, that is not accurate. A light house with good
insulation and located in the right climate needs less heating and cooling than an Earthship.
Landscape
Landscaping is critical to great design, for important
tasks like turning winds into breezes; turning sunlight into food energy and shade; and for minimizing the
reflection of the sun off the ground. Yet, the only hints of how to address
landscape that are provided in the literature are
effectively “do not puncture the roof”, “slope the berm away from the building”, and “do not plant
trees within 20 feet of the tire wall”. But this
makes the building more dependent on systems to perform and offers no advice on
how to make these ideas work.
It is suggested that locating the building on a sloping
site can keep
water from the inside, but there is no guidance on proper site design for this.
In fact, the Hut designs create major water ponding issues right at the front
door. Positive drainage - the design of a site to shed water away from the
building - is a challenging thing to do even for an architect or designer with lots of experience. We
have spent days designing a site for positive drainage before. See our
Landscape chapter for tips and tricks to resolve these issues.
There is a section about harnessing the power of natural
springs, but no mention is made about how springs can become rivers with
rainfall, or how water tables rise and fall though the moon’s cycles. These are
all manageable with good design.
Earthquakes
The Earthship website
talks about the Earthships in regard to Earthquakes. This section specifically
addresses horizontal movement, and suggests using “rubbery” and resilient
materials for building rather than brittle materials like concrete because they
crack.
So, a little Earthquake 101 here: an earthquake’s source, or epicenter, is
always located along a geologic fault line. A well-known example is the San
Andreas Fault in California. The fault line occurs where two tectonic plates meet.
The plates are moving at different rates and different directions, basically
grinding against each other along the fault line. But the fault line is not
perfectly smooth, so the line ‘holds’ the plates from sliding against each
other. When the forces along the fault line become greater than the ability of
a part of the fault line to resist them … boom! The energy is released
explosively as an earthquake. The energy is released as waves through the
earth, very much like a wave in the ocean. When the waves reach the surface of
the earth, where your Earthship might be perched much like a ship on the sea,
your Earthship (or any structure) is tossed horizontally and vertically. We generally think of
buildings as static – they don’t move about. When the earth moves beneath it, a
building resists the movement. This is called inertia – put a salt shaker on a
napkin and yank the napkin away – the bottom of the shaker is attached to the
napkin and has to follow. But the rest of the shaker tries to stay where it
was, and the shaker topples. The same thing happens to our buildings.
Earthquake-resistant buildings (anyone that tells you a
building is earthquake-proof is uninformed or
misleading) are generally both strong and resilient. Strong enough not to
shatter under the earthquake forces, and resilient enough to “give” a little without
breaking. It is a little counterintuitive, but it is that resiliency that
usually helps buildings survive smaller earthquakes with little damage, and in a big earthquake,
resiliency allows a building to bend rather than break, to tilt rather than
topple, so people inside can get out.
The Earthship’s interior walls and the buttresses for the back tire wall are
concrete. So the brittle material argument is moot. As to the insinuation of
the “rubbery” quality of the tires… once they are packed with
earth, the wall acts more like concrete than rubber. So this is moot too.
Walls
The Earthship books cover using wood for framing, but offer no clarification on the
size or types of wood to use, or when it should be harvested.
The website suggests that the aluminum can walls are very strong. However, the strength of the walls is not achieved by the
aluminum, but by the cement that holds the cans together. While aluminum itself is strong, in
this application, it has a smooth surface. There is no way the bond between
cement and metal is stronger than that of, say… porous bricks, to which the
cement can bind at the pore level… and hence it is not as easy to build a truly
strong wall by this means. Also, the way the walls are built requires you to
crush the can a little, decreasing the amount of space that is taken up by the can,
and requiring more cement.
Roof
The roof design from Earthship Volume 1 is not well
designed and uses a huge number of resources. Plus, roof framing should really
follow the pitch of the roof for the best structural performance. Gutters should have a minimum slope so they work.
Earth floors are recommended, but earth floors only work in some climates and they do not
always work for passive solar design, which needs to be modified for the
installation type and climate. Many Earthships now use
flagstone or brick flooring.
Awning windows at the base of the greenhouse against the ground can get buried in snow and cannot provide adequate ventilation unless they are cleared at every snowfall.
That is a maintenance nightmare in cold climates, where some of our
respondents noted that they had to remove snow as many as three times a day to
insure adequate ventilation. There are some design issues with the standard
skylight details too. They must be opened and closed by
the occupant in order to regulate ventilation and solar heating.
If left closed all day they can cause overheating, but if accidentally left
open on cold nights they can vent too much heat. Both windows and skylights are
also notorious for condensation problems. This often contributes to rot and
mold issues.
Maintenance
There is just no way around it: Maintenance-wise, Earthships
are on par with any naturally-built building, if not more so. Day-to-day maintenance on an Earthship can easily be double or triple
that of a traditionally-built building. Earthship systems also require
specialized repairmen that charge a lot for their knowledge and are sometimes
difficult to locate.
Pets and Kids
Your pets may not understand that the planters
are not their personal litter box or
entertainment center. Or that the cistern, if left open to the
building, is not their swimming pool or bathtub. Sometimes, kids may be equally
susceptible. (I know I would have been.)
Pests
In the video From the
Ground Up, there is a moment where we see someone using earth to plaster
the wall and you can see bugs milling about in the plaster. That does not stop
once the plaster dries. In fact, now the bugs have awesome places to build
colonies - in the tires. You might as well prepare yourself early…
centipedes, jerusalem crickets, moths, spiders, snakes, rats, mice… they will
all be your friends in an Earthship. That is totally okay for some people. For
others, it is a terrifying nightmare.
The books, especially Earthship Volume 1, are woefully
out of date. Some of the products offered, like the Dynasphere wind turbine, are investments in less than ideal
technology (see our Wind Power section for an explanation why). There are other
places to look for more up-to-date solutions, and the majority of them are free
online.
