Bamboo engineered housing
Background There are about 23 genera (24% of the world) and 81 species of bamboo (5.2% of the world) found in 73 of the 75 districts of Nepal. The total bamboo coverage area in Nepal is estimated to be around 63,000 hectares, out of which 60 percent is estimated to be in natural forests. Bamboo is more common in the eastern region of the country. Nepal’s total annual bamboo production is 3.01 million culms covering 62,891 hectors of land.
Out of the total annual production of bamboo culms, it is estimated that around 600,000–700,000 culms of bamboo are traded over the commercial domestic market in a year. Out of the remaining 2.4 millions culms, 1.9 millions culms are consumed locally and rest (0.5 million culms) are traded to India. An estimated 102 metric tons of bamboo shoots are also produced and sold in Nepal annually, all of which are consumed locally.
Bamboo is one of the most environmental friendly construction materials. It is known to be one of the fastest growing plants in the world. Its growth rate ranges from 30 cm to 100 cm per day. It attains its maximum size in 60-90 days after shoot sprouting and can be commercially harvested after 3 to 6 years. Bamboo multiplication is very easy and it grows on poor soils, which would not be suitable for many agricultural crops.
This statistics shows that Nepal has enormous bamboo as raw materials with estimated biomass value of 1,060 metric tons. Hence, bamboo has a great potential to contribute to the human and natural ecosystem and environmental sustainability tremendously contributing to economic benefit to the country.
Housing industry in Nepal
[Nepal having the highest urbanization rate 3.79% among the SAARC countries.]
The UN Human Settlements Programme (UN-HABITAT) estimated about one billion rural dwellers and over 600 million urban residents in developing countries live in overcrowded housing with poor water quality, lack of sanitation and garbage facilities. Moreover, the situation is expected to get worse with further increase in population with the world population passing 6.3 billion in 2002 and is expected to reach 8.9 billion by 2050, with higher growth rates expected in the developing countries, as estimated by the United Nations Population Division. By the beginning of the third millennium, it is estimated that 1.1 billion people live in inadequate housing conditions in urban areas alone. Among an estimated 100 million homeless people around the world, available data suggest that increasing proportions are women and children.
According to the information provided by Habitat for Humanity International, majority of Nepalese live in villages and are dependent on agriculture, but severe floods, landslides and earthquakes threaten homes, fields and livestock. Additionally, Habitat’s information emphasis that the lack of employment and poverty has forced one in 10 of the rural population to migrate to the capital Kathmandu and other municipalities. A decade-long rebel insurgency has also driven people from villages to the cities in search of safety. Migration and urban growth have resulted in shortage of adequate housing in towns and cities, crowded living spaces and the growth of sub-standard housing. According to government data, nearly 430,000 families live in dilapidated houses that are unhealthy, prone to collapse and a fire risk – nearly 10,000 families are loosing their homes to fire every year.
A research conducted by Mr. Manohar Rajbhandhari, “Sustainable Building Design and Construction in Nepal with reference to Urban Housing: Issues and Proposed Measures” clearly identifies that the demand of houses are 34,980 every year. Nepal having the highest urbanization rate 3.79% among the SAARC countries.
A report published in a magazine New Business Age titled “Growth by Construction” also highlights few following major reasons for such a growth. First, migration of people because of the Maoist insurgency second, remittance received from the migrant Nepali workers and the housing loan being offered by the commercial banks and finance companies. Added to that is the mushroom growth of approximately 30 operational housing companies.
The report concludes that considering these many factors at play, the growth in construction sector should have been much higher than what is actually been recorded.
According to Nepal government, study conducted some years ago had estimated the need for over 200,000 more houses in Kathmandu Valley only. Considering this huge demand, even half that number would be enough to keep housing businesses going for another 10-15 years, given that the annual supply of new houses every year is only a few hundred, even with the new projects. Furthermore, a recent global housing recession in the world puts a big question on whether Nepal’s housing boom can sustain for a long time.
This massive growth in housing and construction means more people are putting their money in the sector, more people are getting work, and industry is producing and selling more construction material. By one estimate, investment in organized housing in and around Kathmandu Valley already adds up to over Nepalese Rupees (NRs.) two billion
In one hand, housing has emerged as a booming industry in Nepal and similarly, Nepal heavily depends on importing construction materials such as cement, iron/ steels etc. from India. Furthermore, cost of such construction materials including timber has increased extraordinarily in last few years.
A report “Cost of building materials up 10pc” published on the Kathmandu post dated March 14, 2008 reveals that the supply disruptions and a rise in the prices of raw materials internationally have caused the cost of construction supplies to go up by more than 10 percent within the period of two weeks.
Another data made available by the Construction Materials Entrepreneurs Association (CMEA) confirms that the price of Nepali cements also has gone up to NRs. 600 per bag (50 kg) from NRs. 550 only in one month. The price of Indian cement has also increased to NRs. 575, narrowing the price difference between the domestic and imported varieties.
Similarly, the report also adds that the price of iron rods has also gone up by 14 percent during this period to reach NRs. 82 per kg. During the last week of February, 2008 it was being traded at NRs. 72 per kg in the valley resulting to substantial price increase in the input cost.
Not only this sky rocketing growth of the construction materials has forced people to propend their plans of constructing their dream house or finding cheaper alternatives but also the need for affordable housing would help 44% rural Nepali household and 42% as a whole who are below the poverty line to meet their housing demands.
Bamboo and its use for housing
The above information clearly indicates the immense demands for affordable housing in Nepal. In this context, bamboo has a great potential to solve the scarcity of sustainable building materials for high-end and affordable buildings in both urban as well as rural areas. The modern days building materials, which mainly constitute wood, concrete and steel are not consider sustainable materials because they are associated with high-embodied energy. Additionally, bamboo matures in three years, and if they are not used within 10 years, they lose their utility. Hence, bamboo has a great potential to substitute these current materials largely. The recent examples from Europe, South-America and Asia have shown that bamboo can be used to make modern bridges, airports, and even luxury condominiums in addition to affordable, culturally sensitive and earthquake resistant small family homes. Apart from its potential to replace or complement modern construction material, bamboo can be used, as recently seen, to make utilitarian objects like laptops, car interiors, mobile phones and other gadgets, which have a big market potential in developed countries.
[ In Kathmandu, many of the structural elements of ancient houses were built with bamboo ]
In Nepal, around 70–80 percent of the sales of bamboo are traded from the depots (majority of them are located in the cities of Nepal, are used in construction as scaffolding). Most of the handicraft and other enterprises buy directly from the traders. Bamboo has been used for scaffolding for centuries in Nepal. The demand for bamboo for this purpose is one of the biggest in the organize sector. In the year 2005, the three municipalities of Kathmandu, Lalitpur and Bhaktapur approved over 5,000 house plans. An estimated over 130,000 bamboo culms were required as scaffolding to construct these houses. This figure does not include the large amount of rehabilitation, reconstruction and maintenance work being carried out on heritage sites in the Kathmandu Valley. Therefore, it is estimated that, on average, 0.3–0.35 million culms of bamboo may be used every year in construction, costing around NRs. 30–35 million (US $42,000–49,000).
Beside use of bamboo for scaffolding, bamboo has been used in Nepal from centuries for house construction. Bamboo mixed with wood and other materials like adobe, stone has been use in constructing many houses in Nepal to build houses as high as four stories. Some informal sources estimate that around 35% of the houses constructed in eastern part of Nepal especially in Siraha, Suptari, Sunsari, Morang and Jhapa Districts some twenty to thirty years before were made out the bamboo, wood and mud. Even in Kathmandu, many of the structural elements of ancient houses were built with bamboo. Such traditional style of construction still prevails in the Eastern Tarai and other parts of Nepal but unfortunately, these traditional methods of house construction has been replaced by concrete structures.
According to a Nepali bamboo research institute Abari, with a little bit of enhancements almost all the components of a house (like walls, floors, roof, doors, windows, and stairs) can be built with bamboo. Bamboo is lighter in density then steel, but it can be as strong as mild steel in terms of strength. In the last 10 years, there has been emerging interest in the field of bamboo housing in many parts of the globe. Nepal can enhance its existing skill so that it can materialize on the growing global material for this versatile material.
Mr. Shyam Poudel from International Networks for Bamboo and Rattan (INBAR) indicates that bamboo could largely replace timber uses in the construction sector. Market analysis have reveal big potential and economic benefits from the development of bamboo panel based housing, but some issues do exist such as using raw bamboos for the construction of houses have many advantages and disadvantages. Use of raw bamboos is generally cheap, easy and does not require high tech machineries and capital investments. Use of bamboo in housing however, has disadvantages, as it is a non-dimensional material and does not often come with uniform shape, size and age. Raw bamboos cannot resist all kinds of weathers. Especially they are likely to deteriorate in cold dry climates. If bamboos are not treated well then they are highly vulnerable to fungus and termite attacks.
International codes for the bamboo building has been proved by ISO. However, due to lack of national codes of bamboo building in many countries including Nepal, it is difficult to build bamboo houses with raw bamboo.
He concludes that even considering the above-mentioned disadvantages there is however, a great opportunity to promote bamboo for the construction of houses as all the above problems can be solved by converting or processing bamboo into engineered panels. All the disadvantages of natural bamboo would naturally be mitigated once it is processed. Neither its hollowness nor the lack of uniformity would hamper it to use as a construction material. The other great advantage of the panel is that it could be fabricated according to the standard requirement for the housing such as that of timber housing and would solve the problems of building code. It could also be processed into standard size that could be fitted into smaller to large structure.
Major advantages of bamboo prefabricated housing
It is estimated that despite extensive traditional use and availability of bamboo in Nepal, the sector only contributes 1% to the national GDP. Current bamboo applications have failed to capture additional value for the people. Existing market for the panel based (engineered) bamboo housing is almost none in Nepal. Starting the new market for the panel based bamboo housing may take sometime until people start accepting it this is one of the major reasons why use of bamboo in Nepal for commercial purposed other then scaffolding is nominal and untapped to it fullest.
There is no doubt that with the growth of this industry in Nepal, we would be able to provide benefit to the thousands of farmers who are growing and selling bamboo for their livelihoods. Yet, farmers in Nepal have been unable to sell bamboo in commercial manner and fetch a reasonable price. Promotion of bamboo-engineered housing will consume an extensive amount bamboo resulting to commercialization of bamboo farming, processing /production and marketing. Development of this industry will help backward linkages with the rural areas of Nepal and can established a viably supply chain with the existing or potential bamboo housing industries creating a sufficient demands for available raw bamboo. Beside the above-mentioned economic benefits bamboo prefabricated houses will provide the following major benefits to Nepali people: Bamboo prefabricated quality houses are relatively affordable compared to bricks or stone made concrete houses (Current market price of NRs.750/sqft of bamboo prefabricated house compared to NRs. 1700/sqft of concrete house). They are easy to construct, easily detachable and transferable from one place to another and they have good insulation characteristics. These houses are environment friendly and have better earthquakes resistance (The lab test conducted in India supported by DFID has shown that bamboo house can easily stand 7-rector scale of earthquake). Use of bamboo in house construction is a sustainable means as bamboo helps to prevent deforestation. The experience from the INBAR/TNC bamboo housing project revealed that a 30 square meter bamboo house would save about 10 cubic meter of timber. In more general terms: building one small two-room house with bamboo rather than wood could already save at least one big mature tree. A research conducted in Costa Rica revealed that only 70 hectares of bamboo plantation are sufficient to build 1,000 bamboo houses per year. If these houses were built with timber, 500 hectares of natural forests would be destroyed every year. Bamboo processing and production consumes less energy compared to other building materials. It requires only 30 MJ/m3 per N/mm2 compared to concrete, steel and timber, that require 240, 500 and 80 MJ/m3 per n/mm2 respectively. Studies show that processing of bamboo requires only 1/8 of the energy that concrete needs to create a building material of the same capacity. In comparison to steel bamboo needs only 1/50 the amount of energy for processing. Bamboo has a zero waste as all the parts of the bamboo can be utilized efficiently. Bamboo dust has been used for making particleboard and insulation brick. These houses would contribute to the society by providing affordable but quality prefabricated bamboo houses to poor and homeless people. These houses require minimum time to construct and install (minimum of one to maximum of three months) hence, can be effectively used for relief purposes in the times of natural disaster.
Finally, people in Nepal believe that bamboo is a poor men’s timber and living in a bamboo house is a social shame. Because of this stigma people’s perceptions towards the use of bamboo in construction is limited to a temporary solution. Hence, the poor image of bamboo has significantly retarded the potential market of bamboo housing. Therefore, bamboo has to be used extensively not only for affordable housing but also for high-end structures with improved engineering designs in order to raise its image and to change people’s perception.
by: Ujjwal Raj Pokhrel
References
Poudyal P. Punya 2006, Bamboos of Sikkim (India), Bhutan and Nepal, New Heera Books, Kathmandu, Nepal.
Pokhrel Ujjwal Raj 2008, Bamboo in Nepal A Value Chain Upgrading Approach, Strategies and Interventions
Kesari, Vijay P. 2005. Bamboo: From poor Man’s Timber to Green Gold. Hamro Khabar Patrika 15 (164): 10-14, Department of Forest, Kathmandu, Nepal.
UNHCS, May 1999, Basic Facts on Urbanization, United Nations Center for Human Settlements, Nairobi, Kenya. http://www.unhabitat.org/downloads/docs/3777_54054_HS-568.pdf
United Nations Population Division, February 2003, World Population Prospects The 2002 Revision: Highlights, Population Division, Department of Economic and Social Affairs, New York, United States of America. http://www.un.org/esa/population/publications/wpp2002/WPP2002-HIGHLIGHTSrev1.PDF
Habitat for Humanity International website http://www.habitat.org/intl/ap/141.aspx
http://www.asian-forum.net/pdf_2006/CR-WD10.pdf www.nepalnews.com.np/contents/englishmonthly/businessage/2002/sep/cover.htm – 49k
4 Roach, M. 1996. “Bamboo solution” Discover, June 1996, 93-96pp
A report “Cost of building materials up 10pc” published on the Kathmandu Post dated March 14, 2008
KATHMANDU, March 14, Kantipuronline, http://www.kantipuronline.com/kolnews.php?&nid=140791
Nepal Living Standard Survey (NLSS)/World Bank, 1996
Karki M. et. Al. ICIMOD study
J.A. Janssen, 2000: Designing and building with bamboo. INBAR technical report no 20.
Roach, M. 1996. “Bamboo solution” Discover, June 1996, 93-96pp.