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 re investigate the traditional natural materials so that they can be re-appropriated to cater to the modern requirements.
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 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 it 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)
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 skills.
It is in this context that the concept of a specialized research and design institution, which would systematically investigates the material like bamboo and adobe, so that they can address the modern housing need was conceptualized
Abari (Adobe and Bamboo Research Institute) was founded in August 2006. It has designed award winning yurt in Mongolia using adobe, as an alternative to their expensive felt (cotton based traditional material). Abari has also devised portable, low-cost pressurized bamboo treatment plant, that can be used by any small scale bamboo entrepreneur. It is also involved in designing of eco-resorts and training halls in Dhankuta and Janakpur respectively.
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.
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 as well as make it fire retardant.
Goals and Objective:
• To design and construct sustainable structures 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.
• To train interested people on bamboo identifications and treatment, proper storage, joints connections, adobe manufacturing and other specialized construction methods.
Since Abari is research and design firm, it has developed different construction techniques that are unique to the Nepali conditions, so the presence of Abari 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.
Since Abari uses 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.