Earthships: Sustainable off grid living

A dissertation submitted in fulfilment of the requirement

for the degree of
B.Arch
At
School of Architecture and Planning
By

Pragya Lakshmi
2016010348
Table of contents:

1) Abstract
2) Introduction
3) Earthship architecture concepts and principles
3.1 Construction with local and natural materials
3.2 Passive air conditioning
3.3 Energy Production (microgeneration)
3.4 Use of rainwater
3.5 Wastewater Treatment
3.6 Food production
4) Global Model, the Earthship Biotecture project
4.1 Typology, characterization and orientation
4.2Constructive elements
4.2.1Walls
4.2.2Floor and roof
4.3Passive air conditioning
4.3.1Heating
4.3.2Cooling
4.4Rainwater recovery system (SAAP)

5) Challenges
5.1 General weaknesses of Earthships
5.2 Construction
5.3 Maintainance
5.4 Thermal comfort

6) Improvement / optimization suggestions

7) Conclusions

8) Bibliographic references
Abstract
This work describes the investigation and analysis of the challenges of a unconventional
architecture, originated and developed in the USA by Michael Reynolds about 40 years ago,
known as Earthship , a concept that claims that there is no need to resort to active heating and
cooling systems.

This study intends to verify the viability of sustainability and efficient energy and environmental
impact of a residential building and ascertain whether, with this type of construction, it is
possible to guarantee thermal comfort with respect to individual needs.

The primary concern of doing this research is to discover the idea and standards behind the
structures and what could be the potential advantages and disadvantages of building such a
structure. Additionally, to give legitimate data about such structures, and how might it be a bit of
liberty to mankind in future. A survey is to be conducted to know the possibilities and
knowledge of people about the Earthships.
The possible challenges in an Earthship to be listed down in reference to Indian climatic
conditions. Challenges in building, maintaing and living in an Earthship. Global model of
Earthship is to be studied through the plans provided.

Keywords: Earthship , Challenges, Survey, Global model

Introduction
Due to the population growth of humanity, Man is confronted with the dilemma on how to live
sustainably on a finite planet. As a result of the increase in population, there is an excessive use
of energy from fossil sources that produces high emissions of greenhouse gases (GHG), which
causes changes in the planet and reduces its life span. In addition, energy prices have been
increasing in recent years and forecasts indicate that the will continue. In view of these impacts,
today's society in general is confronted with economic difficulties. This set of problems requires
resorting to sustainable solutions, with less environmental impact, less expensive and based on
renewable energies in order to reach a state of “sustainable development”. The “sustainable
development” was an oxymoron that resulted from countless interpretations that justified the
connection of both, “development” and “Sustainability”
According to the Brundtland Commission (1987), a development that guarantees needs of
present generations, without compromising the capacity of future generations satisfy yours, it is a
sustainable development.
This dissertation arises from an interest in the environment and in the future search for a
sustainable resource management, that is, “sustainable development”.
This study analyzes an unconventional architecture, already tested and used, that
started in the USA (United States of America) about 40 years ago, called earthship . This
technology was developed by the American architect Michael Reynolds based on 3 objectives:

1.Create a sustainable architecture;

2.Depend only on natural energy sources;
3.Have economic viability, and can be built by anyone.

An Earthship is an autonomous residential building, built with natural resources, wood and earth,
and recycling waste materials, tires, glass bottles and cans, becoming unique because it aims to
close cycles, with reduced waste production during the life of the building (use phase). "One
man's trash is another's gold."
These homes use passive ventilation systems based on phenomena such as natural convection to
heat and cool indoor spaces, incorporating a rainwater treatment and cleaning circuit that
supplies drinking water. Renewable energy sources are used using modern technology.
Earthship architecture concepts and principles
According to Earthship Biotecture, six principles must be followed:
1. Construction with wasted and natural materials;
2. Passive air conditioning;
3. Energy production;
4. Use of rainwater;
5. Waste water treatment;
6. Food production.

3.1 Construction with local and natural materials

An earthship must use indigenous materials, that is, from the local construction area, with
in order to reduce costs, not only for materials but also for transportation. In this type of
housing, the surrounding walls are built with layers of filled tires, with compacted earth, stacked
interchangeably. The tires form a wall extremely resistant and load. The mass of a tire filled with
compacted earth can reach around 150 kg. The card is used as a base / cover for
keep the soil inside the tire, and the aluminum cans and glass and / or PET bottles (Polyethylene
terephthalate) are used in the construction of interior walls or walls that not subject to load. These
walls are made using bottles and cans, alternated with a mortar of earth and cement, in order to
minimize the use of bricks, cement (or concrete) and achieve good thermal and acoustic
insulation.
In the particular case of glass bottles, after having previously been washed and cut, they are
two bases are joined to allow the passage of light. Glass bottles can be seen as thermal insulation
due to the generation of small air boxes on the walls and are used as a decorative element, similar
to the glass brick, allowing the creation of various designs.

3.2 Passive air conditioning

In winter, as the outside temperature always presents values below the conditions of comfort, it is
important to limit infiltrations, however, the renewal of air interior is a necessary measure to
maintain the interior health conditions of the buildings. Thus, a recommended minimum should
always be ensured through adequate natural, mechanical or hybrid ventilation systems.
The ventilation systems of buildings are intended to contribute to their natural heating and
cooling and are called passive systems. These systems maximize the capture of solar radiation in
the cold season, through gaps that are well-oriented and dimensioned glazing, being able to
associate massive elements, which provide storage and release of energy in the form of heat.

3.3 Energy Production (microgeneration)

Energy consumption in the residential sector varies considerably considering the country in
analysis and according to the habits of the occupants of the buildings.
An earthship is the result of conscious energy design and, by its nature, over time it will bring a
reduction in the electricity requirements for living.
This type of building is equipped with systems to produce its own energy electric and solar
thermal. Electricity is produced by photovoltaic panels and / or by small wind towers with wind
energy seen as a complement, essentially for days of low radiation.

3.4 Use of rainwater

The “sustainable development” of society depends on good management of natural resources and
particularly water resource management.
It was projected for 2030 that the increase in water demand will exceed 40% . The water is the
basis of life, as well as all productive activities from which man depends for your survival. Water
consumption is of high importance at the worldwide, following the observation that this resource,
which seemed inexhaustible, begins scarce, both in quantity and quality, due to increased needs.
Of the water on planet Earth, only about 3% is fresh water, being 2.06% in the polar and glacier
ice caps, resulting in 0.94% of fresh water distributed over lakes, rivers, groundwater and the
atmosphere
The water system of an earthship is a good example. The housing has a system rain and snow
water collection, optional and climate dependent, for consumption domestic. This concept
promotes a more efficient use of water by people and translates into:
• Savings in water consumption;
• Use of rainwater for irrigation and consumption;
• Reuse of gray water for flushing toilets.
The cover has a gentle slope to direct water to the gutters at
downstream, which route it through filtering elements of sand and leaves to the cisterns,
for storage, buried on the north side of the building.

3.5 Wastewater Treatment

All houses have two types of waste water, black water and gray water. Black waters are those
coming from toilets and require treatment before returned to land. The gray waters are the rest,
from washbasins, bathtubs, washes and similar uses. If care is taken to use ecological cleaning
and hygiene products this water can be with a suitable system returned to the land.

3.6 Food production

An earthship must connect with the Earth in order to provide an environment and
space to grow vegetables, fruit and other edible plants throughout the year. At
diets may tend to what is more easily produced in the environment than an earthship
possible, while food production capacities slowly evolve over time
meeting the occupants' wishes. Food production in this type of building is
mandatory if the inhabitants are to be independent. The concept of independence is
very relative in today's society due to overly defined habits, awareness of being
ability to adapt with an improvement perspective.
Global Model, the Earthship Biotecture project

4.1 Typology, characterization and orientation

The characteristics of the EGM are a long and narrow structure, typically one to three rooms
aligned with the east-west axis to maximize exposure to solar radiation, facing south in the
northern hemisphere, and is surrounded to the top by a shoulder of earth, or implanted in a
terrace, by the other three faces of the building.

The south-facing facade incorporates a greenhouse that functions as a corridor and houses a
garden made up of botanical cells used to grow and treat gray waters, which after passing
through the cells, are used for flushing toilets.
The greenhouse is glazed in practically the entire area, with double glazing, with a inclination of
approximately 70º, which should vary according to the latitude and climate of in order to
optimize gains by solar radiation in winter.

4.2 Constructive elements

Next, the elements used in the construction of an EGM are described.

4.2.1 Walls
As previously mentioned, the EGM is erected on a structural wall, in a “u” shape, made with
several alternating horizontal lines of tires filled with compacted earth. At the in the case of
larger typologies, buttresses are added to strengthen the structure of the wall and withstand
possible efforts due to the large mass of compacted soil on the face outside. The greenhouse is
separated from the housing area by a wall glazed with double glazing, and incorporates tilting
windows above the doors that allow ventilation of spaces.

(a) Tire wall of an earthship under construction (b) Interior wall

4.2.2 Floor and roof

The floor is the non-insulated thermal mass, typically stone slabs, tiles, cement or earth. In some
models, wood is applied in certain areas.
The roof has a wooden structure, strongly insulated, with a finishing in lacquered ribbed plate.

Coverage of an EGM

4.3 Passive air conditioning

The increase in energy costs, coupled with the increase in energy demand and a greater
awareness of the concept of energy efficiency in buildings encouraged their construction with
insulation in the surroundings.
In older designs, skylights positioned at the rear of each space for light and fresh air, however,
newer models use buried tubes through the ground shoulder to provide ventilation and heating or
passive cooling. Ventilation intensity can be controlled by operation covers, at the ends of the
ventilation tubes inside the spaces, and is provided by natural convection, generated by the
exhaustion of hot air by the roof of the through operable ventilation skylights.
The thermal mass of the walls and floor stores excess heat and behave like a thermal attenuator,
transferring heat from the ground, relatively stable, inside the building in winter, and outside in
summer.

4.3.1 Heating
Before proceeding with the description and analysis of the passive heating system, let us focus on
the concept of thermal inertia. A building's thermal inertia is its ability to resist temperature
variations inside, due to the predisposition of the building in storing heat in the building elements
and is dependent on the speed accumulation and the amount of heat accumulated in the
building. This property is taken into account some consideration in terms of contributing to the
thermal behavior of the dwelling winter and summer. In winter, it allows the use of solar gains
and in summer absorbs excess heat.
A large thermal mass allows the building to store the absorbed energy for longer periods of time,
that is, the building has a high thermal inertia.
This feature provides an attenuation of the outside temperature extremes and in turn, more stable
interior conditions of thermal comfort, as well as a reduction in the building's cooling or heating
needs. This effect is illustrated in Figure below:

Damping the interior temperature.

Passive heating systems, aearthship incorporates a direct win system, an indirect win system and
a isolated gain system. In the direct gain system of an earthship , the spaces to be heated have
glazing dimensioned in order to allow the maximum incidence of solar radiation in the spaces
and their surrounding thermal masses.
The indirect gain system works in conjunction with the isolated gain system
which, in this type of construction, incorporates a greenhouse that allows a high uptake of
solar radiation and heat storage that is transferred by natural convection through
tilting doors and windows of the spaces. Not with much impact, but with some weight
in the heating of the building, is the use of spaces and metabolic activity of
occupants, as well as electrical equipment.

4.3.2 Cooling
According to the EB ( Earthship Biotecture ) concept , the cooling and intake of new air
it is made, without noise, from pipes buried in the North facade. This technique ventilation
system works as a Geothermal Ventilation System (SVG) . This process is driven by exhaust
skylights in the greenhouse roof, without the aid of mechanical elements. The side panel of the
skylights facing the sun is metallic and without insulation, to absorb and release heat, which
induces an increase in air temperature, stimulating the “chimney effect” caused by the
temperature and pressure gradient between the interior and exterior. This effect is sufficient to
promote the entry and circulation of fresh air in the dwelling. Natural ventilation, if well
dimensioned and applied, can facilitate the air healthiness, as well as thermal comfort and well-
being of the occupants, with a lower energy consumption.
Thermal mass. However, it can have implications for thermal comfort by encouraging loss of
heat by convection and evaporation in the occupants.
Adaptive heating and cooling

4.4 Rainwater recovery system (SAAP)

Rain comes from the condensation of water vapor in the atmosphere that forms drops that, due to
the gravitational force, precipitate until the terrestrial soil. In certain rain passes through
pollutants in the air and on the surfaces where it falls, dragging them with you. Until there is a
chemical analysis of the water to determine its potability, it should be considered non-potable
and used only for purposes such as flushing flushing, washing, cleaning and watering. For
consumption, water must be filtered, boiled or properly treated. Adequate storage must be
ventilated and closed reservoirs to prevent the entry of insects.
Usually, water consumption comes from using showers, flushing toilets, taps, washing machines
or dishwashers and losses. A bath can be immersion or shower, the first being less used and not
sustainable. In an immersion bath 200 liters of water can easily be spent.
The flow rate of a conventional shower can vary between 12 to 20 liters per minute.
In a residence there are at least three to five taps divided between the kitchen and toilet
facilities. Water consumption at taps varies with flow, frequency and time of use, the last two
being difficult to quantify and vary from a few seconds to several minutes. There are taps on the
market with aerators that insert air into the fluid and allow flow rates between 2.8 and 6 liters per
minute.
Currently, domestic washing machines have water consumption lower than previous models,
with consumption between 35 and 200 liters per wash.
In an earthship, water consumption must be moderate and controlled and implies a sequential
treatment in different processes:

1. At the exit of the cistern and through a pump, the water is directed to the
water management, where it is filtered to be used for drinking, bathing and cleaning;
2. The gray water from point 1 is directed to a grease filter and
particles and then to an inner botanical cell 1 ;
3. The recycled gray water, point 2, goes through a peat filter to a tank,
where it will start from, through a carbon filter, to be used in flushing cisterns;
4. The black waters are directed to a proper septic system (solar), from where it leaves
to irrigate an outdoor botanical cell.

(a) Scheme of energy systems (b) Water management module

The system must integrate safety valves in order to direct waste water directly to the septic tank
which in case of overflow must be prepared to redirect wastewater to the municipality's sewers.
 Gray water reuse scheme

General weaknesses of earthships

Earthships require extraordinary periods of time, patience and physical work
to be built. For example, filling a tire with dirt requires about
of three earth handcarts, be well compressed with the aid of a sledgehammer, which
it can take an average of 2 hours and requires intense physical effort.
Some testimonials from earthship users report several problems:

• Moisture due to the use of damp earth when filling tires, which
seemed to facilitate compaction, but ended up blocking moisture inside the
walls and rotting the wood of the roof structure.
• Overheating in the summer which has been resolved by placing devices
exterior shading on the windows of the south facade and roof skylights.
• Improper smells caused by excess fats from the sink kitchens, where the solution was to remove
this component from the water system gray. The Earthships use grease filters, but the occupants
of reports suggest need for frequent cleaning, opting for its removal from the system.
• Lack of insulation on the pavement that contributed to the occurrence of temperatures
inland during the winter and caused the infiltration of humidity which generated the
molds and rotting elements inside the building.
• Humidity problems due to thermal bridges in the greenhouse, poor ventilation and
non-existent humidity control, mainly on humid and cloudy days
Improvement / optimization suggestions

Conclusion
BIBLIOGRAPHIC REFERENCES:

Earthship: Your First Steps: I Want One Michael E. Reynolds

https://www.earthshipglobal.com/
https://www.youtube.com/watch?v=TlntQ9EgOxg
https://www.arch2o.com/earthship-homes-michael-reynolds/
https://architizer.com/blog/inspiration/collections/the-benefits-of-living-
in-an-earthship-home/
http://www3.cec.org/islandora-
gb/en/islandora/object/greenbuilding%3A140
https://www.scientificamerican.com/article/earth-talks-earthship/
https://cshub.mit.edu/sites/default/files/documents/ThermalMassBenefit_v10_13_09
20.pdf
https://urbannext.net/earthship-biotecture/
https://www.builditsolar.com/Projects/SolarHomes/Earthship/Visit/WaterSystem.ht
m
http://lp.hscl.ufl.edu/login?url=http://search.ebscohost.com/login.aspx?direct=true&
AuthType=ip,uid&db=awh&AN=112092922&site=eds-live.