Existing Housing Solutions
College of Engineering and Computer Science
ASSIGNMENT COVER SHEET
THIS SHEET SHOULD BE ATTACHED TO THE FRONT OF YOUR ASSIGNMENT WHEN IT IS SUBMITTED.
STUDENT ID NUMBER: U5036850
Title: Existing Housing Solutions
Team Name: The A Team
Team Number: 22113
Prac Group 5
COURSE NAME: Discovering Engineering
COURSE CODE: ENGN1211
DUE DATE: 02/04/11 (Extention Granted)
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• No part of this work has been copied from any other person’s work except where due acknowledgement is made
in the text; and
• No part of this work has been written by any other person except where such collaboration has been
the course lecturer concerned; and
• No part of this work has been submitted for assessment in another course in this or another part of the University
except where authorized by the lecturer(s) concerned.
Student Signature: James Mitchell Date: 02/04/11
School of Engineering
U5036850
By James Mitchell
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authorised by
Existing Housing Solutions U5036850
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Introduction
The purpose of this assignment is to discuss possible solutions to the housing crises in the small community of
Devikulam in Tamil Nadu, India. I am going to present information involving a few different solutions using
basic building techniques and methods of construction.
The simplest methods used in building houses will probably turn out to be the best. Tamil Nadu is a poor region
of India, and so the majority of the work should be able to be carried of by the local villages, if not all of it.
This in turn will ensure that they will be able to maintain any structures built, long into the future. This also
applies to the materials, which should be available locally. To ensure the structures can be built and maintained
the necessary materials must be available to do so.
The A-Team
The information I will present is a sub-set of a larger project that I am involved in. I am part of a team, known
as The A-Team and we have decided to try and solve the building crisis in Tamil Nadu, India..
Our task is to work out a way to build cheap sustainable houses so that the local villagers can build, repair and
carry out, any ongoing maintainance required to the structures. Local building supplies will be the best materials
to be used, due to their availability and the price of obtaining them.
These houses need to protect the villages from all elements of the local weather, while also contributing to
improving the local community of Devikulam and possibly surrounding communities.
Once the local community of Devikulam has been shown new ways of building and build new structures of
their own, that will improve their lives. They will then be able to pass that knowledge on to surrounding areas,#p#分頁標題#e#
thus the possibilities for helping poor communities in India then becomes limitless. The better the idea, the more
people that will benefit from it in the future.
“Give a man a fish and you feed him for a day. Teach a man to fish and you feed him for a lifetime.” (Lao Tzu.
Tao Te Ching. 6th Century B.C.)
Housing solutions
My research topic is to find existing housing solutions that can than be incorporated by my team with their
findings, so that we can offer the best possible solution.
Environmentally friendly houses have been built for the majority of human history, although in recent times
people have started to master this art. There are many cheap, affordable houses that can be built from basic
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materials. Although for the specific project in mind, we want these materials to be local , thus being easily
obtained and that are easy to handle and build with. Their a few different types of housing structures that could
work for this particular situation. The best ones would be easily made, with as little skilled labour as possible.
Some of the possible solutions would include building with the following resources as the main building
material for each structure: Straw Bales, Rammed Earth or EarthBags . These are all cheap, easily obtained
materials that should be available in the local area.
Straw Bale Houses
A technique for building homes that was born in the USA out of desperation is the Straw Bale house. These
houses are extremely well insulated from the cold and heat. They are easily made, with not a lot of skill
involved for the majority of the work. The only unusual tool required is a Straw Bale needle used to tie bales
together, which is cheap to have made.
The 1st step is creating the base of the the house. This can be done in different ways depending on the climate.
The main feature of this though is to support the structure of the house while also keeping the bales off the
ground, so they stay dry.
There are 2 main types of Straw Bale Houses: Post and Beam or Load Bearing Houses
The Post and Beam method is a modern way of building Straw Bale houses. The house is built and supported
with wooden Beams and Posts and the straw bales are then placed around these for insulation.
A Load Bearing House is the traditional Straw Bale house, where the weight of the structure is held up by the
straw bales themselves. This would be a good approach to take in Devikulam due to the fact that the walls can
be very quickly erected once the base of the house is in place. Local villagers would be able to stack the the
bales themselves due to the lack of skill needed, and this would save a lot of time and money. The method is
simply to stack the bales around the house and tie them down from top to bottom, with each proceeding row to#p#分頁標題#e#
be half a bale further along than the one before. This is done to add strength to the house and prevent cracking
in the same way that brick houses are built. There are many different types of straw that can be used to make
straw bales. These can be wheat straw, rice straw, pine straw and bailey straw. This gives a lot of different
options to obtain the materials essential for building these structures.
Existing Housing Solutions
Straw Bale homes are extremely durable with some hou
In Nebraska, U.S.A. 70 Straw Bale homes were built between 1896
and most of them in excellent condition, with the straw still of the same quality as recently h
The energy efficiency of Straw bale homes is extremely good. Straw bale walls have an R
this is about 2- 3 times the rating of a very well insulated conventional home.
Figure 1. A Load Bearing Straw Bale House
Straw bale homes are very resiliant to rain, and can be protected very well with wide roofs if needed. If they do
get wet, they dry out quite easily, as long as a
climates, Plasters such as lime or Earth should be used to allow this.
However, their can be problems if the straw bales have moisture levels of above 20% for long periods of time.
Straw Bale Homes are a lot more fire retardant
that can be taken though is to add borax to the plaster. This makes it more fire retardant, acts a rodent repellant
and as a fungicide. Although in the building process the structure is vulnerable to fire. A clean work site is
essential and people have to be conscious of things that could create a spark and start a fire. No smoking on site,
would have to be strictly imposed.
Earth Ramm
houses that were built in the 1800's still standing.
1896-1945, of these at least 13 of them still exist
(http://www.dulley.com/docs/f750.htm
plaster is used that allows the bales to breath. In wet or humid
than conventional houses built out of wood. An extra measure
uilding Rammed Houses
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ses harvested straw.
R-rating of R35 to R50
htm)
Existing Housing Solutions
As early as the 1st century A.D. there is a written record of these types of structures being built by the Romans.
Parts of the Great wall of China were made in 2000 B.C. using this type of method that have survived to the
present day. Earth Rammed houses have been used all over the world, with structures lasting hundreds of years,
if not thousands. They are unarguably, extremely strong, sound structures that protect from all the elements of
the weather. The thermal advantages of using earth st
the building cool in the winter. An added advantage of earth structures is that they will survive in termite
invested areas, such as Western Australia.
Figure 2: An Earth Rammed house
(http://www.contractortalk.com/f3/job
Buildings made by the Earth Rammed process are extremel#p#分頁標題#e#
there are many methods of constructing them. Earth ramming tools can be used to build structures quickly,
aided by front loading tractors that can be used to collect soil quickly and efficiently.
However the cheaper methods of building Earth Rammed houses are of course the traditional methods. They
can be compacted by hand, using two boards on either side of the wall and compacting earth inside them. The
frame work once built can by used over and over a
expensive to make, but are labour intensive. Although this can be very good for poor villages, that don't have a
lot of money, but do have the people who can work together to build houses for each other.
Once a small work force has been briefly trained in this method of construction they can come together and
build entire villages.
A problem with Earth Rammed houses is that they take a lot longer to make than conventional houses. The
walls once compacted need time to dry, which can take up to 3 weeks. This is one of the main reasons they have
mmed structures are that they retain heat in the winter, but keep
in construction
job-site-meeting-weekend-house
extremely cheap since the primary material used is earth and
r again as a kind mold for houses. These houses are not
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ructures house-72424/)
y gain
Existing Housing Solutions
not taken off in main stream markets such as France, Australia and the U.S.A. Although processes are being
developed to reduce the construction time.
Ear
An Earth bag house is one of the cheapest methods of building a home. It requires no special tools or skills to
build the majority of the house. Most of the structure can be made with a shovel and bags to fill with dirt,
although, you can use other materials such as sand or clay. The best combinations would be a mixture of dirt
and clay or a clay and straw mixture, however dirt does quite well on it's own.
Figure 3: An Earthbag house before the outer walls are completed (http://sustainabledesignupdate.com 2011)
The structure can be built completely out of dirt bags, including the roof, or it can be made using timber framing.
The first step in preparing the base is to remove or the subsoil, which can be collected and used in packing the
bags. A trench for drainage can be made with rubble and this is usually used as the foundation.
It is advisable the area is dug down to undisturbed ground, so that the
can be used in bags as the base, as to lift the structure off the ground to give it added protection.
The Earthbags insulate the structure very well and also protect from flooding, rain and strong winds.
Earthbag houses are similar to Earth Rammed houses except they are more flexible in the way they can be
constructed. They are less labour intensive, and easier to build with and are capable of making curves and#p#分頁標題#e#
domes on structures. This enables the designer to
structures, with designs to fit the individual's
added strength value.
The important thing about making Earthbag houses is that
supported by the bags themselves than you want to make sure that the bags are strong enough to withstand the
Earthbag Houses
g structure is built on solid ground. Gravel
bag be more creative with the design, and build a large variety of
preference. Structures that are round, curved or domed have an
the choice of bag that is used. If the
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structure is to be
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pressure. Polypropylene bags are the most commonly used, because they're strong and cheap. However these
types of bag will deteriorate in direct sunlight, so it's important to plaster the structure as soon as possible. If the
building is going to take more than 2 months to make, the bags should be covered to protect them from U.V.
Rays. This will stop them the bags deteriorating and ensure their quailty.
Recommendations
The three building methods I have presented all construct practical, cheap, well insulated homes, that protect
from the elements, such as rain and fire. They're all built with local materials that are easily obtained and need
little skills to build. However there are different strength and weaknesses in these structures.
The Straw Bale Houses can be made very quickly and can last at least a hundred years, but run the inherent risk
of high moisture levels. If the do get wet they can dry out if the correct plaster has been used in the construction.
They can't handle moisture levels over 20% for along periods of time though. This could be a problem in humid
areas, but not necessarily. If constructed in a humid area, they do come with this risk though.
Earth Rammed houses have survived the test of time, lasting thousands of years and used all over the world in
every kind of climate. With a small team of people who have had a little bit of training, entire villages can be
constructed. However, they can be time consuming to build compared to conventional houses and other
alternative methods. The Earth Ramming method can also only make straight edges, so the designs can be
limited.
EarthBag houses have all the benefits of Earth Rammed houses, except they might only last a hundred years due
to the bags deterioting.They are however quicker to make, and people don't necessarily need training to
construct them. They aren't limited in the kinds of designs they can produce which is an added benefit to the
people that the houses are for. Rounded, curved or dome structures are not only easy to make, but recommended
for there strength. For these reasons the Earthbag house's would be the most suited to the situation in
Devikulam. They could be made without a group of people, women and children could also help pack the bags.#p#分頁標題#e#
Although the Earth Rammed houses would be an excellent alternative.
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References
1 Corum, Nathaniel (2005). Building a Straw Bale House: The Red Feather
Construction Handbook. Pg2-50
2 Elizabeth, Lynne. Adams, Cassandra. Alternative Constructions:
Contemporary building methods. Pg152-209
3 Bingham, Wayne J. Straw Bale Home Plans. Pg3-37
4 Rael, Ronald. Earth Archetecture.Pg20-24
5 Mostaedi, Arian. Sustainable Architecture: Low Tech Houses
6 Minke, Gernot. Building with Earth. Pg19-24
7 Morrison, Andrew. www.strawbale.com. Accessed: 30/03/11
8 Barrie,John.www.sustainabledesignupdate.com. Accessed: 30/03/11
Bibliography
10 Rauch, Martin. Rammed
11 Prat, Rachel Hiller. How to build straw houses.
12 Dr. Owen Geiger. www.greenhomebuilding.com. Accessed 30/03/11