Flats and fears
Traditional housing methods in the Northeast need to be saved from gradual disappearance. Not only because they reflect the region’s heritage but also offer lodgings that agree with its varied climatic conditions
Jayanta Kumar Sarma
An aerial view of the largest north-eastern city, Guwahati, can throw back a picture replete with apartment buildings. As much as these tall, concrete structures -- most of which are haphazardly built on narrow patches of land --signify the city’s apparent economic prosperity, they also point at the near bankruptcy of its once so common traditional look. Rarely do you now find a house in the city that may be called a traditional Assamese dwelling or a style somewhat close to it.
Placed in a volatile seismic zone, not just Guwahati but the entire North East increasingly going for such methods by following the fad of adopting modern housing need to save a thought soon on the wisdom behind the traditional housing styles once ubiquitous in the region.
One needs to also keep in mind that the north-eastern region of India is also prone to high rainfall, floods and landslides besides its seismic vulnerability. Being placed on an expanse covering parts of the Eastern Himalayas and the Purvanchal hills, on plateaus, river valleys and depressions with the altitudinal variation of 200 metres to over 8000 metres from the sea level, the region has certainly a wide variation of physical environmental base. It has a distinct variation of agro-climatic zones with varied climate and weather regimes. All the more reason to understand that one model just can’t fit all.
Besides, housing is also a part of a community’s heritage. If lost, a precious lot will be lost. The region has a wide diversity of ethnic groups. About 250 of them. Their diversities reflect in the specific style of housing adopted over the generations, not only to suit the physical environment they live in but also to showcase their craftsmanship and a community’s identity.
It is a given that in all geographical situations, the traditional housing design of a region reflects its approaches of adjustments to the physical environment besides expressing social dimensions. The physical environmental is linked to its terrain condition (e.g. slope, soil, etc), climate and weather related situations (e.g. rainfall pattern, temperature, threats of calamities, etc) and locally available building materials (e.g. for construction of plinth, wall, floor, roof, etc). Safety and security is another aspect considered in specific design and the spatial arrangement of housing. Usually, threats of foe and wildlife along with safety from fire and slope destabilisation, earthquake, floods, etc. are also considered in all forms of traditional housing. The family structure ( joint or nuclear), gender role in a family and society, pattern of social groups and social institutions, religious beliefs and practices, environmental perception and folk traditions are some of the important aspects of social conditions which play a significant role in the design and setting of traditional houses.
The specific arrangement and space utilisation plan are a reflection of the different community’s pattern of priorities. Here, one can offer the example of the Dimasas living in the Borail hills of Dima-Hasao district of Assam. Traditionally, they prefer a forest cover around their residential areas, which functions as a buffer to the habitation and a source of supply of basic requirements of food, fodder, fuel, medicine, etc. from the wild. Their houses are in rows, one facing the other. They have the provision of breaking the wind flow, done by putting split bamboos in front of each house (plate 1)
It can be mentioned here that most tribes living in the hills have their dwellings on bamboo or wooden stilts for the ease of placing them on slopes and saving them from frequent destabilization (plates 2, 4 and photo 1).
In case of internal space utilisation, the priorities are different with different communities though provisions for a fireplace, kitchen, the space to sleep, store, etc. are common to most ethnic groups (plate-1, 2, 3, 4).
Over the period of time, with changing social requirement, some changes can be noticed though. For example, in traditional Khasi houses, some new patterns have evolved with the priority now on a nuclear family and the need to stay in a separate house (plate-5).
In many cases, new safety and security considerations rising from frequent ethnic conflicts have also led to some changes. Many hill tribes such as the Nagas, Kukis, Hmars, etc. prefer to construct their houses on hilltop, particularly in location where from the entire village landscape or at least the village entrance can be seen. In certain cases, they design an outlet in such a way that one has to enter it through a particular approach (as in the case of Rabha houses seen in photo -2).
Interestingly, traditional housing of many tribal communities also showcases many crafts such as wood crafting, as in the houses of Maram Nagas (photo 3,4,5) and in the houses in the Satras of Majuli ( photo 6).
The basic building material used for the walls and the poles are bamboo, wood, even betel nut trunks. Thatch, palm leaves, betel nut leaves, etc. are used to cover the roof. Since their durability is very short -- usually 4 to 5 years, nowadays in many areas such methods are replaced by GI sheets.
However, from the perspective of earthquakes, since most of the traditional building material used like bamboo and thatch are lighter in weight than, say, GI sheets, they are less likely to cause deaths and injuries. Having a better structural property where its fibre runs parallel to the axis of culm and bends inside the node, bamboos have lesser probability of breaking in such a situation. The elasticity of bamboo is high anyway -- on average 1.5 to 2.0 x 105 kg /cm – clearly helpful in seismic resistance.
A recent study by Earthquake Engineering Research Institute (EERI) and International Association for Earthquake Engineering (IAEE) for housing in the northeast region with special reference to Naga housing with a bamboo platform ( as a case study ) observed that the lateral load of the housing structure, building configuration and roofing are most appropriate from the perspectives of earthquake safety. However, wall and roof connection and wall opening, construction and craftsmanship need more improvising.
This may be a matter of time since one can see new approaches already coming up in some traditional housing. For example, in certain areas, mud block based housing is evolving. Some such practices can be seen in Deb-Barman villages of Tripura and the Rabha and Garo villages of Goalpara in Assam (plate-6). It may be mentioned here that a similar type of traditional building is there in Northern Chile called ‘Adobe’. The Meghalaya Science Technology and Environment Council has introduced the mud brick technology in the State recently through different demonstration projects.
However, one needs to keep in mind a parallel change which is detrimental to the cause. It is therising influence of different modern models of housing, done without much thought with market-based building materials. This has clearly affected the traditional housing styles. People have started using many market-based building materials in the difficult terrain condition too. There is a negative aberration to this. With the change of building materials, from the environmental perspectives, the energy used in construction increases.
The thermal efficiency, particularly the thermal comfort level of such material in comparison to bamboo and mud, is less (in the present day perspective along with strength, stability, durability, environmental and energy dimensions are also considered to determine the efficiency of a building.) Moreover, structural design change increases the vulnerability of slope destabilisation in hills and highland areas. Though the National Building Code of India in its structural design section under Timber and Bamboo allotted three specific codesfor the use of round bamboo, split bamboo and for bamboo mat in 1973, 1976 and 1979 respectively, there is a need of further research in the area and to define ways for improvisation of these traditional housing along with appropriate coding so that one can get support of the financial institutions like banks for such constructions and get insurance coverage too.
The issue is important from the perspectives of having environment friendly and earthquake resistant dwellings for all in the Northeast, as well as to give a fillip to our traditional practices and help their preservation.
(Jayanta Kumar Sarma is a freelance consultant in the area of Environment and Development and he has been working with NGO, Educational Institutions, private entrepreneurial farm and government agencies of North-east region. He did his Post graduation in Geography from Gauhati University and Post Master in Natural Resource Management from IIFM.)