Modern Structures Using Bamboo and Adobe

Background:

The name Bagar suggests a bank. Sanfe Bagar is a town
located in the river bank. Like many other areas of
Nepal, it is prone to earthquake and torrential rain
which could be followed by flooding or landslide. In
traditional knowledge the most important way to cope
against water induced disaster is a sound site selection.
On hilly areas, construction are always made on top of
stable land known as pahara. Cliffs or lands that can
slide off are avoided. Roof constructions are always done
with light-weight material like bamboo or/and reed. Thick
walls are constructed using locally manufactured adobe or
stones.

Orientations are always made to the south, to capture the
southern heat.

Despite the historical prominence of bamboo and adobe,
the productivity using these materials is remarkably low.
Owing to limited and disappearing knowledge, lack of
skills and basic tools, and the cultural bias associated
with these materials, there is very little interest among
modern dwellers to use these natural materials.
The quality of craftsmanship, especially for bamboo, is
generally poor due to several reasons: bamboo used for
construction is not mature enough, bamboo is not treated,
improper handling, lack of knowledge about jigs, poor
jointing and lack of finishing materials and skill.

Goals and Objective:

• To design and construct sustainable telemedical center
using traditional material like adobe and bamboo which
is sensitive to the environmental, social, cultural
and topographic conditions of the area.

• To reuse and redesign the traditional material like
adobe and bamboo so that it can cater to the modern
sensibility.

• To construct structures that can harness solar energy
and use household waste for energy generation.

• To design structure that can effectively resist
earthquake and flooding and other water induced
disasters.

• To train interested people on bamboo identifications
and treatment, proper storage, joints connections,
adobe manufacturing and other specialized construction
methods.

Design Rationale:

Total Area: 200 sq. m (excluding courtyard)

Cost: Rs. 9610 (155$) per sq. meter maximum or total of
$32000 for 200 sq. meters and courtyard (the cost would
be flexible if the materials and all the skilled labors
were found at the site).

Form:

Form of the space is triangular with rounded corners.
Rounded corners and the triangular shapes are
aerodynamic, they deflect the fierce wind and rain and
the rounded corners make bonding between two walls
stronger thus making it effective against earthquakes.
Furthermore, bamboo bracing on adobe walls are effective
earthquake and landslide resistant. A plinth level of
stones are used in order to combat torrential rain or
even flooding.

The space is divided into three courtyards. Courtyards
provide evaporate cooling thus making the thermal level
optimal. Courtyards make seemless integration between the
inside and outside space, thus making the interior
multifunctional.

The first courtyard is for the visitors to the
telemedical center. Second is for the community members
who have come to visit the library and computer center.
The third courtyards is only limited to the staffs of the
telemedical center.

Construction Material:

Bamboo for roof rafters, columns, earthquake
reinforcement and partition walls.

Adobe for structural walls and it also provides thermal
mass.

Stones with cement mortar for foundation and plinth.

Stone slates for roofing material.

Green mud roof that has live plants for roofing for the
structures that are in the middle of the courtyard.

Cement for bamboo connection and moisture barrier.

Steel rods, small pieces for bamboo connection.

Adobe and Bamboo:

Adobe (sun dried bricks) has been used all over the
world, for centuries, because of its superior thermal and
acoustic quality. The oldest remaining structures of the
world are made of adobe. In Nepal, Basantapur Durbar, Bal
Mandir, Singha Durbar and many other Rana Palaces, along
with the traditional vernacular architectures are classic
examples of adobe buildings. Adobe buildings are warm in
winter and cool in summer. Reinforced with bamboo, they
can effectively withstand earthquake. Another advantages
included ease extraction from the earth and a minimal
manufacturing cost.

An adobe or any earth building is not only healthy for
the planet but creates a healthy environment for those
who dwell within, as such a building avoids toxic
materials used in conventional construction and the
“breathable walls allow for the release of any toxins
which may have been introduced within the structure”.
(Hallock 295)

In the research done by Grenot minke of Germany, it was
found that in the building where interior walls were made
of earth, the relative humidity was nearly constant over
the years varying from 45% to 55%. From the research done
by Grandjean(1972) and Bekert (1986) we know a relative
humidity of less than 40% over a long period may dry out
the mucous membrane, which can lead to decreased
resistance to colds and related disease. If this
absorption and transportation system is disturbed by
drying out, these foreign bodies reach the lungs and may
cause health problems.

While adobe creates a salubrious environment, bamboo
provides structural integrity to a building. Furthermore,
adobe is good in compression and bamboo is good in
tension, which make them a perfect match to resist
earthquake. Bamboo is straight, hollow, smooth and light
yet hard and strong. It is pliable and flexible which can
be easily bent or split, yet it can be as strong as mild
steel. It grow more rapidly than trees and start to yield
within three or four years of planting. If it takes 60
years for a tree to grow 60 feet, bamboo can grow as tall
in 60 days.

Eighty one species (out of 1,573 species or 5.2% of the
world) of bamboo belonging to 23 genera (out of 96 ) have
been found in Nepal (Poudyal 2006). Nepal has both
tropical bamboo found in South-East Asia and temperate
found in Tibet and Bhutan)

Rationale:

In 1997, at Kyoto Protocol, countries around the world
agreed to reduce the use of following materials by the
year 2020.

Reinforcing steel by 80 %.

Aluminum by 90 %.

Cement by 85%.

There were needs to make these promises because according
to a survey, building in use or in the course of erection
are the largest sources of carbon emission, which account
for over 50% of the total world emission.
Instigated by environmental consciousness, health,
aesthetic and economic reasons, people are showing,
albeit small, a reinvigorated interest to go back to
natural building materials like adobe and bamboo. In
Nepal too, we are seeing a modest institutionalized
effort to reinvestigate the traditional natural materials
so that they can be re-appropriated to cater to the
modern requirements.

Apart from the high energy cost associated with
extracting of concrete and steel, at the present
inflation rate, the concrete and steel building is out of
reach of many middle and low income household.

Furthermore, due to the rise in health related diseases,
attributing to the low relative humidity present in the
concrete houses, there is growing need and interest among
many people to look for an healthier and sustainable
alternative to the conventional housing practices. By
constructing structures using adobe and bamboo we can
give healthier modern option to the conventional building
practices.

Scope:

Any structure that can be built using concrete and steel,
and be efficiently and cost effectively done with bamboo
and adobe. There are certain cases where little cement
might have to be used for foundation, joints and as
moisture barriers. With the proper overhang roof and good
foundation, bamboo and adobe can last for a long time. It
is however, recommended to use treated bamboo in order to
increase durability and to make it fire retardant.

Approach:

The designer, Entrant 2008, is a research organization that has developed
different construction techniques that are unique to the
Nepali conditions, so the presence of the designing organization is required
from the design to the construction phase. In the work
process, it will also train the local people about its
specialized construction methods, so that the skills can
be transferred to different regions.

Project Duration:

Since the designer requires natural materials, it has to follow
harvesting cycles. Harvesting and treatment of bamboo and
adobe manufacturing can only be done in dry seasons. It
requires three-four months to treat bamboo. The
construction requires 2 to 6 months depending on the
scale of the structures. The recommended time to initiate
the project is September-October.

Location