ANALYSIS OF DETERIORATION OF TRADITIONAL MUD HOUSES AT RURAL AREA OF BANGLADESH

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1 ANALYSIS OF DETERIORATION OF TRADITIONAL MUD HOUSES AT RURAL AREA OF BANGLADESH Khandoker Tariqul Islam, 1 B. Arch, Lecturer, Bangladesh University, tariqarch@gmail.com Ruksana Aforz, B. Arch, Lecturer, Bangladesh University, ruksana.afroz@yahoo.com ABSTRACT Traditional mud house is an ancient tradition and is considered as the finest example of sustainable green housing choice in the South Asia. With the recent trend in urbanization, mud house construction has decreased at an alarming rate. Mud houses are being replaced with brick houses and corrugated iron (CI) sheet houses. The goal of this research was to look into the factors that are contributing to this decline and compare its sustainability in terms of climate, energy requirement and cost. This article also elucidates factors affecting the adaptability of traditional mud houses into the changing societal dynamics of the post-modern era. A typical village from Gazipur district in Bangladesh was taken as the study area because traditional mud houses are still abundant in this district. Temperature, Relative Humidity (RH) and Light penetration data were collected through field survey in mud houses, brick houses and CI sheet houses. These data were analysed to compare their thermal comfort. Field survey and interview of dwellers and construction workers of these three housing choices were conducted to collect information regarding liveability, cost, time and social aspects that relate to their housing choices. The result of this research shows that though mud houses have better thermal and acoustic comfortability, ease of maintenance, cost effectiveness and other positive aspects, mud houses are failing to sustain due to some wired social phenomenon that has arisen in the recent times. Economic growth negatively influences mud houses with regards to preserving this tradition. More research on adaptation and modification of traditional mud houses and social awareness program may help mud houses to stand a chance in this competition. The results of this study can be helpful in developing architectural guideline for saving mud houses and other traditional buildings from becoming extinct. Keywords: Traditional mud house, thermal comfortability, sustainable heritage, social issues etc. 1 Corresponding author 1

2 Abbreviations: CI sheet = Corrugated Iron sheet, RH= Relative Humidity, UNESCO= United Nations Educational, Scientific and Cultural Organization, BDT = Bangladesh Taka, sft =square feet. INTRODUCTION The knowledge of vernacular architecture has developed in time to fulfill the demand of the local users and is being tested for thousands of years. Traditional housing methods represent heritage and values fundamental to the culture of the people of a community. It possesses distinct characteristics such as planning, use of locally available building materials and geoclimatic location. Traditional housing has been to change with industrialization. For centuries, houses of Bangladesh have been built by locally available materials, e.g. mud, straw, grass, bamboo, jute stalk. It is only from that late 19th century that locally available materials began to be replaced by industrially produced materials in building houses, e.g. cement, brick, corrugated iron sheet, steel bar. (Rashid R., 2007) Recent choices of construction material and housing plans do not seem to consider traditional knowledge of settlement for this region at all. The engineers and dwellers are rather trying to copy the urban living style. This approach has cost us the loss of traditional heritage, lifestyle and comfort of living in a mud house in this region. The contemporary housing style has also increased energy demand and carbon footprint. AIM & OBJECTIVES The aim of this study was to investigate the reasons for disappearance of traditional mud houses at rural areas through a comparative analysis with the contemporary brick house and CI sheet house, which are now commonly used as alternative dwellings of mud houses. The objectives of this study are as follows: 1. To investigate the thermal comfortability of traditional mud houses and compares it with brick houses and CI sheet houses. 2. To explore the financial aspects of building a mud house in contrast to its brick house and CI sheet house in terms of construction cost, durability and maintenance. 3. To evaluate the indoor environment of a mud house in comparison to brick house and CI sheet house in terms of thermal comfort, aesthetic finishing, architectural beauty and dweller comfort. 4. To find out the issues that may discourage a dweller from building and living in a mud house. TARGET STUDY AREA Village: Begunhati, Post Office: Raniganj, 2

3 Thana: Kapasia, District: Gazipur Study period: November 2013 Flood zone = No Electricity supply = Yes Transportation and road communication = Good Material availability = All traditional and modern building materials were fairly available Primary economic activity = Agriculture CLIMATE OF BANGLADESH Comfort of living in a place widely depends in context of regional climate as per classifications of Terjung and Maunder s Human Climatic Index based on 13 climate features (Houghton, 1985) or a simpler classification based on air temperature and relative humidity (Koenigsberger, 1973). Bangladesh lies between 20º34 N to 26º33 N and 88º 01 E to 92º 41 E. It is in the Indo-Malayan Realm as per UNESCO in terms of ecological region or biomes. The climate of Bangladesh was categorized as warm-humid by Atkinson. (Koenigsberger, 1973) Although a large part of the country s land mass lies on the Tropic of Cancer, the tropical nature of the climate is attributed to the regional geographical character. Generally the climate of Bangladesh gets short and dry winter, moderate to hot and humid summer. It also gets a rainy season that is characterized by incessant downpour with recurring floods due to the Himalayan mountain range and Tibetan Plateau being in the north. (Hossain and Nooruddin, 1993) The humidity is fairly high during the summer and the rainy season and is very often above 80%. Average temperature is 34.5ºC in the summer and the rainy season while it is 12.7ºC during the winter. (Rashid R. and Ahmad M. H. 2010) METHODOLOGY This research was conducted through an empirical survey for investigating thermal comfortability of the dwelling choices of interest. On site survey and in person interviews were the key tools for exploring other relevant factors of interest. Three houses situated in similar microclimatic situation in the target area were surveyed. Thermal comfort analysis was conducted quantitatively by measuring both indoor and outdoor humidity (RH) and temperature (ºC) using Humidity/Temperature meter (Lutron HT-306) in November Data were collected in two different days at regular interval of three hours from 3.00 PM to PM. Measurements were taken at different places inside the houses, immediate outdoors (courtyards) and outdoors. A parallel study was also conducted in different homesteads around the same courtyard in different orientations to measure thermal performance of mud houses built in different orientations. Finally subjective assessment of thermal comfort in indoor environment was assessed based on obtained data and statistical analysis. Another measurement was taken to 3

4 observe indoor light amount for the three selected houses in same outdoor lighting conditions by using Digital Lux Meter (Lutron LX-101). 42 dwellings were surveyed on site and 37 people were interviewed. Six of the interviewee was mud house construction workers, 15 have lived in all three kinds of houses in their life time and 16 have lived only in mud houses. Information on construction cost and time for a 15ft X 30ft mud house, brick house and CI sheet house were collected from 6 construction workers. The in-person interviews were recorded and analyzed to evaluate relevant issues of interest. DESCRIPTIONS OF SELECTED HOUSES Mud house Brick house CI sheet house Wall = 2 mud wall Roof = CI Sheet Floor = Mud plinth Ceiling = Wood Indoor paint = No Outdoor paint = No Wall = 5 brick wall with plaster Roof = CI Sheet Floor = Cement Ceiling = Bamboo Indoor paint = No Outdoor paint = No Wall = CI Sheet Roof = CI Sheet Floor = Mud plinth Ceiling = CI Sheet Indoor paint = No Outdoor paint = No Table 1: Characteristics of the houses surveyed Figure 1: (a) Layout of Mud house (b) Layout of Brick house (c) Layout of CI sheet house 4

5 Figure 2: (d) Mud house (e) Brick house (f) CI sheet house (g) Mud house s interior (h) Brick house s interior (i) CI sheet house s interior. OBSERVATIONS AND ANALYSIS Thermal comfortability After completion of temperature measurement and analysis of data, the following outcomes were observed: The indoor air temperature in mud house is less affected by the outdoor temperature (Figure 3) which indicates a better thermal performance in any weather condition than brick house and CI Sheet house. The indoor temperature of CI sheet house is affected by outdoor temperatures more than the other two choices. Mud house contains a comfortable amount of humidity and did not change rapidly with the outdoor humidity change, unlike brick house and CI sheet house (Figure 4). With this analysis it is clear that mud house provide better thermal comfort level with compare to other two house type. Brick house perform less and worst performance by CI sheet house. 5

6 Figure 3: Indoor temperature of different dwellings and outdoor temperature at different times of the day Figure 4: Indoor relative humidity of different dwellings and outdoor relative humidity at different times of the day Construction feasibility The number of mud house construction workers are decreasing as the demand of mud houses is also decreasing. Masons are taking their place as the demand of 6

brick house is increasing. This study reveals that building a mud house takes at least six times more time than building brick house or CI sheet house.

Figure 5: Comparative analysis of different dwellings in term of construction time & per sft cost.

As a result damping and molding is a big threat to the houses of this region.

CI sheet decays even faster due to moisture and rain.

7 brick house is increasing. This study reveals that building a mud house takes at least six times more time than building brick house or CI sheet house. However, the construction costs of brick house and CI sheet house per sft are at least four times and two times more than that of a mud house respectively. Figure 5: Comparative analysis of different dwellings in term of construction time & per sft cost. Maintenance Rural areas, moisture content level in earth and air is much higher than in urban areas of Bangladesh (Figure 6). As a result damping and molding is a big threat to the houses of this region. In our survey, we found that the brick house s plaster des not last more than years due to exposure to excessive moisture. CI sheet decays even faster due to moisture and rain. Surprisingly, mud houses last much longer in this climate as it absorbs moisture protects itself from the damaging effects of high humidity and rain. Figure 6: Comparative humidity analysis of rural and urban area on a similar day (left). Brick plaster wall and CI sheet wall are affected badly by moisture (right). Therefore, due to moisture and others issues mud house is more durable than brick house and CI sheet house. A brick house s life span is years and CI sheet house lasts for years needing major repairs every 3 to 4 years. A mud 7

house s life span is more than 200 years and needs minimal repairs, though every year.

between the erosion of mud house and brick house.

sheet house Indoor lighting doesn t depend much on building material.

8 house s life span is more than 200 years and needs minimal repairs, though every year. Mud house 200 years old Mud house 22 years old Brick house 8 years old Figure 7: Comparison between the erosion of mud house and brick house. Indoor environment, aesthetics and usability of a mud house in comparison to brick house and CI sheet house Indoor lighting doesn t depend much on building material. Though mud house can t provide wide windows, the amount of light inside the house was found adequate in the survey. Though it is possible to widen mud house openings by using modern building materials, it increases the construction cost. Figure 8: (1) Mud wall painted with chemical paint and mud plinth covered with cement finish (2) Mud wall covered with plaster 8

9 Floor finish quality becomes a big disappointment in case of mud house from user point of view when compared to the modern cement floor finish. Brick house and CI sheet house comes with net cement flooring and sometimes tiled floors. Attempts to bring luster to the earthen floor of mud house with vinyl sheets and other plastics were found to be widespread among the dwellers. Wall finish is also a big problem of mud house interior. Though chemical paint and lime wash is not suitable for mud wall, the dwellers often apply these to improve the interior and exterior visual quality. Brick house and CI sheet house do not have this problem. Mud house performs poor in terms of indoor environment quality and aesthetics in comparison to brick house and CI sheet house. It is mentionable that adaptations of visual performance of houses have changed as people are moving towards urbanization and have developed liking for the beauty of urban housings. Social issues & other factors influencing the decline in mud houses Per capita income in this region has increased significantly in the last 20 years years due to foreign remittances and industrialization. With positive changes in their economic condition, people are trying to improve their lifestyle. Introduction of electricity has helped them a lot in this regard. As communication network has spread to the remote places, cities are now one step away. The rural populations consider the cities as ideals of beauty and try to replicate that in their rural habitats. Building brick house is not subject to their need but more subject to their status. Most of the brick house and CI sheet house owners are not happy with the thermal comfort; yet they built brick houses as it is a symbol of their better financial status. DISCUSSION AND CONCLUSION The showing off of financial status by building brick house and CI sheet house in rural areas of Bangladesh is now affecting the societies to such an extent that the mud house owners find themselves outclassed by many of the same community. As a result, most of the mud house owners and their children have trouble finding a bride or groom to marry. As a cherished tradition and heritage, mud house should be patronized by all quarters of the society because of its thermal comfort, environment-friendly features and adaptability to rural environment. Though mud house takes more time to construct, it is more economically viable considering low construction and maintaining cost and its longevity. The reasons of mud houses disappearance lies mostly in degrading social values, less exploration in aesthetics and lack of synchronization with modern technologies. Social workers and the government organizations should play active role in building awareness about mud house and help instill its acceptance among the minds of the rural people. Further 9

10 research is needed involving architects, engineers and social workers to improve the indoor visual quality, interior finishes and acceptability of mud houses in rural Bangladesh. LIMITATIONS This study was conducted only in the target area, which may or may perfectly represent similar communities elsewhere in Bangladesh. The quantitative measurements were taken at the start of winter due to time constraint. Though actual readings differ significantly during the other months of the year, the temperature and relative humidity change throughout the day in a very similar fashion. CONCLUSION Reasons behind decreasing number of mud houses are not thermal comfort, cost or durability. Though there are problems with interior finishes and indoor visual environment, the main reason of decrease in mud house number is social degradation. Only social awareness and innovations for improving the aesthetics and usability of mud house while keeping traditional values in mind can save this finest example of green housing and our vernacular heritage. ACKNOWLEDGMENTS We are grateful to Mr. Irfan Ahmed Khan for reviewing and editing this article. REFERENCES Houghton, D.D. Ed. (1985) Handbook of Applied Meteorology, John Wily & sons, Canada. Hossain, M.E. and Nooruddin, M. (1993) Some Aspect of Urban Climates of Dhaka City, International Technical Conference on Tropical Urban Climates, Dhaka, Koenigsberger. (1973) Manual of tropical Housing and Building Design, Part I, Orient Long man. Rashid R. and Ahmad M. H. (2010) The Comparison between The Thermal Performance of a Contemporary House and Traditional House in the Dense Dhaka City in Bangladesh: A field study was conducted at Dhaka city in Bangladesh, Conference on Technology and Sustainability in the Built Environment. CAPSKU Saudi Arabia 3-6 Jan, Rashid R. (2007) Traditional House of Bangladesh: Typology of house according to materials and location, Virtual Conference on Sustainable Architectural Design and Urban Planning AsiaSustainabilityNet.upc.edu September 15-24,

CHAPTER 6 CONCLUSION

255 CHAPTER 6 CONCLUSION This study thoroughly assessed the design principles employed in simple, durable and eco-friendly vernacular dwellings in the coastal regions of Tamil Nadu and their effectiveness