The Earthships are legendary for being ultra-affordable and
doable by anyone, which is exactly what Mike Reynolds hoped they would be and
this ideal… this story… is what gets passed on from each generation to the
next. The issue is that the data does not fully support the noble idea that adopters
of this technology wanted to be true.
There is no way around this but to face it: Earthships are
one of the most expensive, most labor-intensive, most technologically
demanding, and time-consuming structures out there. They are also not as
sustainable as they are reported to be, which we will go into further detail
about throughout this chapter. The Earthships of today cost $225+ per square foot (PSF). This is confirmed
in a 2007 study by researchers Kruis and Heun, which found that the cost to build an off-grid Earthship at that
time averaged $162 PSF, a grid-tied Earthship averaged $107.50 PSF, and a
standard stick-frame home cost $97.75 PSF. Adding in 7 years of inflation
brings those numbers close to the $225 mark of today’s builds. Several
designer/builders have confirmed that their Earthships cost around $200 PSF.
This data belies the assertion that the Earthships “cost about the same as a
conventional home”, since a conventional home costs from 1/2 to 2/3 of that
depending on the techniques used.
The cost myth is further exacerbated by other means as
well. While tires, glass bottles, and aluminum cans may be “free”… the plans and permits,
excavation, tools, 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 systems… are not.
Plus, nearly every piece of an Earthship is custom-fabricated and therefore
comes with the delays of custom construction and often, a higher cost. If you
are a do-it-yourselfer, this can be OK, but if you are paying for labor and you
are on a budget… maybe not so much.
Reality Check: Base costs of an Earthship
When we ran the numbers on a Global Model 3 bedroom
Earthship, and then compared them to build budgets from our research, the base price for an
unfinished building was $179,000 in U.S. dollars.
Excavation $
20,000
Tools $ 5,000
Roofing $
35,000
Concrete & Rebar $
17,000
Front wall framing +
Windows $ 20,000
Cooling tubes $
5,000
Cisterns $ 7,000
Thermal wrap and poly
sheets $ 10,000
Systems Package $
60,000
$
179,000
While these base prices may seem high, and they are... many
homes need these items. Building a home costs money, no matter how you go about
it. Some homes cost more than
others. The off-grid Earthship is one such home.
The cost issue is even further exacerbated because “early
adopters” of any technology often pave the way for future builders. It can be quite
expensive for the early adopter to test an idea, as they have to become a
scientist: they first devise a theory – the design and plans – and then find
the funding to prove the system works. Even strawbale construction, which has been around for a very
long time, has only recently been accepted for use in seismic zones. This
approval only came once full scale structural testing of the system had proven it
to work. The change came from people taking a chance and building and then
testing the system to prove it could withstand the loads. The good news is, in
leading the charge for more sustainable and natural design, we improve the
chances for others to get to use what we prove works.
We offer these initial costs considerations here because
budgeting data for Earthships, overall, is pretty lacking or outright avoided,
which might explain why so many builds run over budget. These cost considerations are also why we decided to
cover building types in this book that are a bit more expensive and/or a bit
more “out there”. If you are going to spend this amount of money, you should
get exactly the kind of home you want.
So let’s address some of the cost aspects of the materials typical to Earthship
builds…
Land
One of the factors that people often miss when planning a
build is the cost of the
land. The Earthship has a huge footprint of up to 3,500 square feet including the berm (this high density per square foot ratio is
part of what makes it non-sustainable) which means you really need an acre to
place it on. Land can cost anywhere from $5,000 to $100,000 an acre depending
on where you build. To combat this, many have made the mistake of buying cheap
land for their building, but cheap land usually is not ideal for settlement. We
will cover why this is a bad investment and what makes an ideal build location
in Chapter 4.
Tires
An average Earthship requires about 900 tires for its back wall. But those tires are most
likely not located on your building site. Or within 10 miles of your
building site. Because, most likely, you are going to be “out there” where it
is still okay to do experimental architecture. To get the tires to your site,
you will need to make time to go select them out of a tire dump, which can take
20 hours or more, and then transport them the however many miles between the
dump and your land. One option would be to get them all in one load
on an 18-wheeler, which can carry 800 tires. But there are road access issues
to address, rental and fuel costs, and driver hire issues with that. So, let’s
look at a more practical option… you can get up to 50 tires piled and tied into
the bed of a standard pickup truck and get it done in 16 loads. (Have you
budgeted to sell your fuel-efficient hybrid and get a pickup truck?) How much
mpg does the truck get? What is that cost per load? Times 16 loads? According to the EPA
report, “Scrap Tires: Handbook on Recycling Applications and Management for the
U.S. and Mexico” from December 2010, the cost of transporting one tire in an
average 25 mile haul (12.5 miles each way) is nearly $0.50. Multiply that by
900 tires and we have a fuel cost of $450 for tires.
A horse trailer would be another
great option for this work. Know someone who has one you can borrow?
There is a lot of debate on whether the tires are a good idea or not because of potential
off-gassing of dangerous chemicals. To learn more about
this debate, see Tires and the Off-gassing Issue and Chapter 2.
Cans
The average number of uncrushed soda and beer cans used in an Earthship is 10,000. You can drink
all that yourselves, but it comes at a price - buying the drinks - which you
may well do for a two year build using volunteers. But you can get creative
too! One of the most ingenious ways we have heard of is from a renowned
Earthship build in Canada. Manitoba Earthship Project partnered with the
Winnipeg Folk Festival to collect the cans from the recycling bins at the
festival! That garnered them more 12,000 cans in one week. However you get the
cans, if you do not get them delivered, you need to get them to the site. If you pack them well, you
can get 4,000 cans in the bed of a pickup truck. That is three loads, for
planning purposes. Then, you want to budget time and water for washing them out
so the house does not reek of beer and soda or attract pests.
Glass Bottles
You will need 2,000 bottles to make the standard 1,000
bottle bricks for the beautiful bottle walls. Those easily fit in one
truckload if you pack them tightly and organized like a honeycomb. More likely,
however, you will do it in several less organized truckloads as you are able to
go to the recycle center and sort them. Predict three loads minimum for that.
Plan 2 hours for sorting and bagging per load. You will want to plan for enough
water and cleaning time to get these cleaned up as well. An easy way of getting
all the bottles you need in one day might be to partner with a local wine
festival and take all their empties. You might not get the colors you want, but
you will get a lot of bottles quickly. Like with the cans, the number of loads and gas
required to bring them back to your site will depend on the vehicle used and distance
traveled.
Cement and Concrete
We did a takeoff off of plans for a Global Model Earthship
to help budget for cement and concrete costs. Contrary to popular belief, concrete
makes up the majority of the materials used in the build. Here is the overview
of how much concrete might be needed: (Please note that haul numbers do not
include sand or aggregate.)
Hidden Costs
One thing we noticed in the research – mileage and time is not included in the
budgets for most builds. Now add volunteer’s driving time and mileage, plus the
mileage for family and friends who help, inspectors, and near daily trips to
the hardware store or into town for more water. Fuel costs and time involved
are real hidden costs that can make or break a project. When added to the cost of feeding, watering, and insuring volunteers, these hidden costs can
derail a build.
Additional costs to plan in advance
for:
- Propane costs for cooking, clothes drying, space heating, and on-demand water heating.
- Backup water supply.
- Backup power supply.
- Re-mudding the earth plaster each year.
- Re-staining or oiling the exterior wood each year.
- Periodic septic cleanouts.
- Periodic cistern cleanouts.
- PV battery banks should be replaced every 15 years.
- PV panels should be replaced every 25 years.
Emotional Costs
One of the negative factors that came up repeatedly in our
research is the
emotional cost of
building an Earthship. A build can negatively impact a person’s: sense of
privacy, financial stress, employment, physical state,
happiness, and sense of comfort and safety. A build can also have an impact on
a person’s relationships with people in general, and their relationship with
their spouse in particular. This is something to consider for those who might
want to build a home inspired by the Earthship model, especially for those who
may be especially sensitive to these energies and emotions.
There is more to discuss
about the affordability equation and it deals with more of
the legends around the Earthships.
