01.1 Background
How sensitive are you of the built environment that you live in? Have you ever come across a building that is rather ordinary but is fascinating and has a story behind it? Have you ever wondered why people build the way they do or why they choose that material over others or even why the building faces in that direction.
Fig 1- Palmyra House Nandgaon, India (Style-Contemporary; Principles-Vernacular)
In answering these questions we need to look at the communities, their identities and their tradition over time and this in essence is what is called “Vernacular Architecture’’.
The purest definition of vernacular architecture is simple…it is architecture without architects. It is the pure response to a particular person’s or society’s building needs. It fulfils these needs because it is crafted by the individual and society it is in. In addition the building methods are tested through trial-and-error by the society of which they are built until their building methods near perfection (over time) and are tailored to the climatic, aesthetic, functional, and sociological needs of their given society. Because the person constructing the structure tends to be the person who will be using it, the architecture will be perfectly tailored to that individual’s particular wants and needs.
Much of the assimilation of the vernacular architecture that we see today in India comes from the trading countries. India is a place which has many different cultures and has seen rapid economic growth over the past few decades which not only transforms people’s lives but also changes everyday environment in which they live, people in the nation are faced daily with the dual challenges. On one hand modernization and on the other preserving the heritage including all their built heritage. This gives us multiple perspectives on vernacular environments and the pure heritage of the country.
Fig 2-A modern adaptation of brick façade along with the contemporary design of the building. https://www.archdaily.com/530844/emerging-practices-in-india-anagram-architects
Gairole House, Gurgaon, Haryana, India
“Vernacular buildings’’ across the globe provide instructive examples of sustainable solutions to building problems. Yet, these solutions are assumed to be inapplicable to modern buildings. Despite some views to the contrary, there continues to be a tendency to consider innovative building technology as the hallmark of modern architecture because tradition is commonly viewed as the antonym of modernity. The problem is addressed by practical exercises and fieldwork studies in the application of vernacular traditions to current problems.
The humanistic desire to be culturally connected to ones surroundings is reflected in a harmonious architecture, a typology which can be identified with a specific region. This sociologic facet of architecture is present in a material, a color scheme, an architectural genre, a spatial language or form that carries through the urban framework. The way human settlements are structured in modernity has been vastly unsystematic; current architecture exists on a singular basis, unfocused on the connectivity of a community as a whole.
Fig 3-Traditional jail screens, Rajasthan, India
Vernacular architecture adheres to basic green architectural principles of energy efficiency and utilizing materials and resources in close proximity to the site. These structures capitalize on the native knowledge of how buildings can be effectively designed as well as how to take advantage of local materials and resources. Even in an age where materials are available well beyond our region, it is essential to take into account the embodied energy lost in the transportation of these goods to the construction site.
Fig 4- Anagram Architects, Brick screen wall: SAHRDC building, Delhi, India
The effectiveness of climate responsive architecture is evident over the course of its life, in lessened costs of utilities and maintenance. A poorly designed structure which doesn’t consider environmental or vernacular factors can ultimately cost the occupant – in addition to the environment – more in resources than a properly designed building. For instance, a structure with large windows on the south façade in a hot, arid climate would lose most of its air conditioning efforts to the pervading sun, ultimately increasing the cost of energy. By applying vernacular strategies to modern design, a structure can ideally achieve net zero energy use, and be a wholly self-sufficient building.
01.2NEED FOR STUDY
Buildings use twice the energy of cars and trucks consuming 30% of the world’s total energy and 16% of water consumption by 2050 they could go beyond 40%
Emitting 3008 tons of carbon which is the main cause of global warming.
In India a quarter of energy that is consumed goes in making and operating the buildings. Also almost half of the materials that we dig out form the ground goes into construction of buildings, roads and other construction projects. Hence, buildings are a very large cause of the environmental problems that we face today. Therefore, it is really important to re-demonstrate that good, comfortable sustainable buildings can play a major role in the improvement of our environment as well as can keep par with the modern designs and can perform even better than them.
The form and structure of the built environment is highly controlled by the factors such as the local area architecture or climate etc. In situations like these we need to study the forms in respect to our environment.
In India there is a whole lot variety of climate ranges and a constant need for developing architecture that will support the environment. We as architects need to study modern designs as well as the functions of the built form in respect to the local climate and cultural context.
VERNACULAR Architecture the simplest form of addressing human needs, is seemingly forgotten in modern architecture .But the amalgamation of the two can certainly aid to a more efficient built form.
However, due to recent rises in energy costs, the trend has sensibly swung the other way. Architects are embracing regionalism and cultural building traditions, given that these structures have proven to be energy efficient and altogether sustainable. In this time of rapid technological advancement and urbanization, there is still much to be learned from the traditional knowledge of vernacular construction. These low-tech methods of creating housing which is perfectly adapted to its local area are brilliant, for the reason that these are the principles which are more often ignored by prevailing architects. Hence, the study of this subject is much needed for better architects of future that are sensitive to the built form and the environment as well.
01.3 AIM
This study aims to explore the balance between the contemporary architecture practices Vis a Vis the vernacular architectural techniques. This work hinges on such ideas and practices as ecological design, modular and incremental design, standardization, and flexible and temporal concepts in the design of spaces. The blurred edges between the traditional and modern technical aspects of building design, as addressed by both vernacular builders and modern architects, are explored.
OBJECTIVE-
The above aim has been divided among the following objectives-
• Study of vernacular architecture in modern context.
• Study of parameters that make a building efficient.
• To explore new approaches towards traditional techniques.
• Study of the built environment following this concept.
• To explore approaches to achieve form follows energy.
01.4 FUTURE SCOPE
The effectiveness of climate responsive architecture is evident over the course of its life, in lessened costs of utilities and maintenance. A poorly designed structure which doesn’t consider environmental or vernacular factors can ultimately cost the occupant – in addition to the environment – more in resources than a properly designed building. For instance, a structure with large windows on the south façade in a hot, arid climate would lose most of its air conditioning efforts to the pervading sun, ultimately increasing the cost of energy. By applying vernacular strategies to modern design, a structure can ideally achieve net zero energy use, and be a wholly self-sufficient building.
Hence, the need to study this approach is becoming more relevant with the modern times.
01.5 HYPOTHESIS
Fusion of the vernacular and contemporary architecture will help in the design of buildings which are more sustainable and connect to the cultural values of people.
01.6 METHODOLOGY
01.7 QUESTIONAIRES
• Is vernacular architecture actually sustainable in today’s context in terms of durability and performance?
• How vernacular architecture has influenced the urban architecture of INDIA?
• Local architecture or modern architecture which is more loved by the locals that are living in the cities compared to the locals living the rural area?
• Will the passive design techniques from vernacular architecture contribute in the reduction of environmental crisis due to increasing pollution and other threats?
• Modern architecture has evolved from the use of concrete to steel and glass and other modern materials. What is the reason that the sustainability of local materials were compromised during these times which led to the underrated statement or a norm that vernacular architecture is village architecture as stated by the majority today ?
02.1Introduction
The discussion and debate about the value of vernacular traditions in the architecture and formation in the settlements in today’s world is no longer polarized.
India undoubtedly has a great architectural heritage which conjures images of Taj Mahal, Fatehpur Sikri, South Indian temples and Forts of Rajasthan. But, what represents Modern Architecture in India.
India has been a country of long history and deep rooted traditions. Here history is not a fossilized past but a living tradition. The very existence of tradition is proof in itself of its shared acceptance over changed time and circumstance, and thus its continuum.
This spirit of adaptation and assimilation continues to be an integral aspect of Indian architecture in the post-independence era as well. As such post-Independence India had voluntarily embraced modernism as a political statement by inviting world renowned Modern architect Le Corbusier to design capital city of young and free nation with democratic power structure.
Despite strong continuum of classical architecture from Indian traditions, these new interventions gained currency and came to be preferred choices for emulation of architects of the following genre. Not only Corbusier, even Louis Kahn, Frank Lloyd Wright and Buck Minster Fuller had their stints in India, Indian masters also got trained and apprenticed overseas, under international masters and continued the legacy forward.
Figure 1 Terracotta Façade –A traditional material used to create a modern design for a façade https://in.pinterest.com/pin/356910339198958537/
02.2Vernacular architecture
02.2.1 Definition
Vernacular architecture is an architectural style that is designed based on local needs, availability of construction materials and reflecting local traditions. Originally, vernacular architecture did not use formally-schooled architects, but relied on the design skills and tradition of local builders.
Figure 2 A Traditional Kerala house https://in.pinterest.com/pin/538672805410302086/
Later in the late 19th century many professional architects started exploring this architectural style and worked while using elements from this style. Many of those architects included people such as Le Corbusier, Frank Ghery and Laurie baker.
Vernacular architecture can also be defined as the “architecture of people “with its ethnic regional and local dialects. It is an aware style of architecture coined by the local builders through their practical knowledge and experiences gained overtime. Hence, Vernacular architecture is the architectural style of the people, by the people, for the people.
02.2.2 Influences on the vernacular
Vernacular architecture is influenced by a great range of different aspects of human behavior and environment, leading to differing building forms for almost every different context; even neighboring villages may have subtly different approaches to the construction and use of their dwellings, even if they at first appear the same. Despite these variations, every building is subject to the same laws of physics, and hence will demonstrate significant similarities in structural forms.
Climate
One of the most significant influences on vernacular architecture is the macro climate of the area in which the building is constructed. Buildings in cold climates invariably have high thermal mass or significant amounts of insulation. They are usually sealed in order to prevent heat loss, and openings such as windows tend to be small or non-existent. Buildings in warm climates, by contrast, tend to be constructed of lighter materials and to allow significant cross-ventilation through openings in the fabric of the building.
Buildings for a continental climate must be able to cope with significant variations in temperature, and may even be altered by their occupants according to the seasons.
Buildings take different forms depending on precipitation levels in the region – leading to dwellings on stilts in many regions with frequent flooding or rainy monsoon seasons. Flat roofs are rare in areas with high levels of precipitation. Similarly, areas with high winds will lead to specialized buildings able to cope with them, and buildings will be oriented to present minimal area to the direction of prevailing winds.
Climatic influences on vernacular architecture are substantial and can be extremely complex. Mediterranean vernacular, and that of much of the Middle East, often includes a courtyard with a fountain or pond; air cooled by water mist and evaporation is drawn through the building by the natural ventilation set up by the building form. Similarly, Northern African vernacular often has very high thermal mass and small windows to keep the occupants cool, and in many cases also includes chimneys, not for fires but to draw air through the internal spaces. Such specializations are not designed, but learned by trial and error over generations of building construction, often existing long before the scientific theories which explain why they work.
Culture
The way of life of building occupants, and the way they use their shelters, is of great influence on building forms. The size of family units, who shares which spaces, how food is prepared and eaten, how people interact and many other cultural considerations will affect the layout and size of dwellings.
For example- In the city of Ahmedabad, the dense fabric of city is divided in pols, dense neighborhoods developed on the basis of its community and its cohesion.Traditionllay the pols are characterized by intricately carved timber framed buildings built around a courtyards with narrow winding streets to ensure a comfortable environment within the Hot Arid climate of Ahmedabad. The design of these settlements also included stepped well and ponds to create a cooler microclimate, these are a great example of ecological sustainability with the Cultural influences.
Figure 3 Mud house Gujrat, Traditional mirror work done on the elevation of the hut https://in.pinterest.com/pin/439875088574491684/
Culture also has a great influence on the appearance of vernacular buildings, as occupants often decorate buildings in accordance with local customs and beliefs.
For example- Warli art a form of representation of stories through simple forms like circles triangles and square are a form of decoration as well as a cultural tradition.
02.2.3 The Indian vernacular architecture
India is a country of great cultural and geographical diversity. Encompassing distinct zones such as the great Thar desert of Rajasthan, the Himalayan mountains, the Indo-Gangetic Plains,the Ganga delta, the tropical coastal region along the Arabian sea and the Bay of Bengal,the Deccan plateau and the Rann of the Kutch, each region has its own cultural identity and its own distinctive architectural forms and construction techniques that have evolved over the centuries as a response to its environmental and cultural setting. A simple unit of the dwelling has many distinct forms which depend on the climate, material available , social and cultural needs of the community.
Indian vernacular architecture the informal, functional architecture of structures, are unschooled informal architectural design and their work reflects the rich diversity of Indian climate, locally available building and materials and intricate variation in local social custom and craftsmanship. It has been estimated that worldwide close to 90% of all buildings is vernacular, meaning that it is for daily use for ordinary, local people and built by local craftsman. The term vernacular architecture in general refers to the informal building structures through traditional building methods by local builders without using the services of a professional architect. It is the most widespread form of building.
Indian vernacular architecture has evolved over time through the skillful craftsmanship of the local people. Despite the diversity, this architecture can be broadly divided into three categories.
• Kachha
• Pakka
• Semi pakka
“Vernacular traditions are a dynamic and creative ‘processes through which people, as active agents, interpret pat knowledge and experience to face the challenges and demands of the present. Tradition is an active process of transmission, interpretation, negotiation and adaptation of vernacular knowledge, skills and experience.”
-Asquith and Vellinga(2006)
IMG-Vellore house, Chennai, India
The architecture that has evolved over the centuries may be defined as the “architecture without architects”
1. KUCCHA BUILDINGS
They are the simplest and most honest form of buildings constructed using materials as per their availability. The practical limitations of the available building material dictate the specific form. The advantages of a Kuccha is that construction materials are cheap and easily available and relatively less labor is required. It can be said the Kuccha architecture Is not built for posterity nut with a certain lifespan in mind after which it will be renewed.
According to Dawson and Cooper (1998), the beauty of kuccha architecture lies in the practice of developing practical and pragmatic solutions to use local materials to counter the environment in the most economically effective manner.
For example in the North East, Bamboo is used to combat a damp, mild climate while in Rajasthan and Kutch ,mud, sunbaked bricks and locally available material is used to mould structures ;in the Himalayas they often use stone and sunken structures to protect themselves from the harsh cold. While in the south, thatch, coconut palms is used to create pitched roofs to confront a fierce monsoon.
MATERIALS-Mud, Grass, Bamboo, Thatch or sticks, Stone, Bamboo, lime
TECHNIQUE OF CONSTRUCTION: Construction of these houses were constructed with earth or soil as the primary construction material. Mud was used for plastering the walls.
IMG-House dwellings in Himalayas with sunken construction and stone used as insulating materials to block winds during harsh winters, HIMACHAL PRADESH
2. PUKKA BUILDINGS
The architectural expression of Pukka is often determined by the establishments or art form which has been developed by the community, such as WARLI paintings. The Pukka buildings are generally built with permanence in mind. Often using locally available materials. Often using locally available materials, the pukka architecture has evolved to produce architectural typologies which are again region specific.
MATERIALS-Stone, brick, clay etc.
TECHNIQUE OF CONSTRUCTION- Construction of their house are done using masonry structure which may be brick or stone, depending upon the locally available material in the region where the structure is constructed, Manual labor is much high in construction of these structure than the kachcha houses.
3. SEMI PUKKA BUILDINGS
A combination of the kachcha and pukka style together forms the semi- pukka. It has evolved as villagers have acquired the resources to add elements constructed of the durable materials characteristic of a pukka house, Its architecture has always evolves organically as the needs and resources of the local people residing in the specific region. The characteristic feature of semi pukka houses are that these houses has walls made from pukka material such as brick in cement/lime mortar, stone, clay tile but the roof construction is done in the kachcha way using Thach, bamboo etc. as the principal material of construction. Construction of these houses employs less manual labor than that of the pukka houses. Thach roofing Mud Adobe walls with Lime plaster.
02.2.4 CLIMATE RESPONSIVE ARCHITECTURE
The Climate of India comprises a wide range across its terrain. Five zones that can be identified in India on the basis on their climate are Cold, Hot and Dry, Composite, Temperate and Warm and humid.
Figure 4Climate zones of INDIA
Source- http://high-performancebuildings.org/climate-zone.php#;
These zones can be further narrowed down to three on the basis of passive techniques used and architectural styles of different regions.
1. HOT AND DRY
2. WARM AND HUMID
3. COLD
• HOT AND DRY
The hot and dry zones of India include Ahmedabad, Rajasthan, Madhya Pradesh and Maharashtra.
A hot and dry climate is characterized by a mean monthly maximum temperature above 30 ºC. The region in this climate is usually flat with sandy or rocky ground conditions.
In this climate, it is imperative to control solar radiation and movement of hot winds. The building design criteria should, thus, provide appropriate shading, reduce exposed area, and increase thermal capacity.
Design Considerations for building in Hot and dry climate-
The hot and dry climate is characterized by very high radiation levels and ambient temperatures, accompanied by low relative humidity. Therefore, it is desirable to keep the heat out of the building, and if possible, increase the humidity level. The design objectives accordingly are:
(A) Resist heat gain by:
• Decreasing the exposed surface
• Increasing the thermal resistance
• Increasing the thermal capacity
• Increasing the buffer spaces
• Decreasing the air-exchange rate during daytime
• Increasing the shading
(B) Promote heat loss by:
• Ventilation of appliances
• Increasing the air exchange rate during cooler parts of the day or night-time
• Evaporative cooling (e.g. roof surface evaporative cooling)
• Earth coupling (e.g. earth-air pipe system)
Figure 5 JODHPUR CITY CLOSELY STACKED HOUSES TO PREVENT HEAT GAIN AND TO PROVIDE SHADE Source- http://www.traveldglobe.com/destination/jodhpur
(a) Planning: Indigenous planning layout was followed for places and simple small dwellings as seen in Shahjahanabad, Jaisalmer and many other cities in India. This type of a dense clustering layout ensured that the buildings were not exposed to the outer sun. This prevents the solar gain and the hot winds from entering the premises and also allows the cold wind to circulate within the building.
Figure 6 Hot and dry region settlement https://www.slideshare.net/sumiran46muz/hot-and-dry-climate-65931347
(b) Waterbodies: Use of waterbodies such as ponds and lakes. These not only act as heat sinks, but can also be used for evaporative cooling. Hot air blowing over water gets cooled which can then be allowed to enter the building. Fountains and water cascades in the vicinity of a building aid this process.
Figure 7 AMBER FORT RAJASTHAN, INDIA A garden is positioned amidst the lake to provide a cooler microclimate for outdoor sitting.
Source-https://commons.wikimedia.org/wiki/File:Maota_Lake.JPG
Figure 8 Earth berming technique: Evaporative cooling through water feature Source-http://mnre.gov.in/solar-energy/ch5.pdf
(c) Street width and orientation: Streets are narrow so that they cause mutual shading of buildings. They need to be oriented in the north-south direction to block solar radiation.
Figure 9 Design techniques in Hot and dry regions Source-http://mnre.gov.in/solar-energy/ch5.pdf
(c) Open spaces and built form: Open spaces such as courtyards and atria are beneficial as they promote ventilation. In addition, they can be provided with ponds and fountains for evaporative cooling.
Courtyards act as heat sinks during the day and radiate the heat back to the ambient at night. The size of the courtyards should be such that the mid-morning and the hot afternoon sun are avoided. Earth-coupled building (e.g. earth berming) can help lower the temperature and also deflect hot summer winds.
Figure 10 Courtyard planning of Hot and dry region Source-http://mnre.gov.in/solar-energy/ch5.pdf
(2) Orientation and planform
An east-west orientation (i.e. longer axis along the east-west), should be preferred. This is due to the fact that south and north facing walls are easier to shade than east and west walls.
It may be noted that during summer, it is the north wall which gets significant exposure to solar radiation in most parts of India, leading to very high temperatures in north-west rooms.
For example, in Jodhpur, rooms facing north-west can attain a maximum temperature exceeding 38 ºC. Hence, shading of the north wall is
Imperative.
The surface to volume (S/V) ratio should be kept as minimum as possible to reduce heat gains.
Cross-ventilation must be ensured at night as ambient temperatures during this period are low.
(3) Building envelope
(a) Roof: The diurnal range of temperature being large, the ambient night temperatures are about 10 ºC lower than the daytime values and are accompanied by cool breezes. Hence, flat roofs may be considered in this climate as they can be used for sleeping at night in summer as well as for daytime activities in winter.
Figure 11 Flat roof for reverse heat gain during night Source-http://mnre.gov.in/solar-energy/ch5.pdf
The material of the roof should be massive; a reinforced cement concrete (RCC) slab is preferred to asbestos cement (AC) sheet roof. External insulation in the form of mud phuska with inverted earthen pots is also suitable. A false ceiling in rooms having exposed roofs can help in reducing the discomfort level.
Evaporative cooling of the roof surface and night-time radiative cooling can also be employed. In case the former is used, it is better to use a roof having high thermal transmittance (a high U-value roof rather than one with lower U-value). The larger the roof area, the better is the cooling effect.
The maximum requirement of water per day for a place like Jodhpur is about 14.0 kg per square meter of roof area cooled. Spraying of water is preferable to an open roof pond system. One may also consider of using a vaulted roof since it provides a larger surface area for heat loss compared to a flat roof.
(b) Walls: In multi-storeyed buildings, walls and glazing account for most of the heat gain. It is estimated that they contribute to about 80% of the annual cooling load of such buildings .So, the control of heat gain through the walls by shading is an important consideration in building design.
(c) Fenestration: In hot and dry climates, minimizing the window area (in terms of glazing) can definitely lead to lower indoor temperatures. It is found that providing a glazing size of 10% of the floor area gives better performance than that of 20%. More windows should be provided in the north facade of the building as compared to the east, west and south as it receives lesser radiation during the year. All openings should be protected from the sun by using external shading devices such as chajjas and fins.
Moveable shading devices such as curtains and venetian blinds can also be used. Openings are preferred at higher levels (ventilators) as they help in venting hot air. Since daytime temperatures are high during summer, the windows should be kept closed to keep the hot air out and opened during night-time to admit cooler air.
Figure 12 Louvers for providing shade and diffused lighting
http://www.nzdl.org
The use of ‘jaalis’(lattice work) made of wood, stone or RCC may be considered as they
Allow ventilation while blocking solar radiation.
(a) Color and texture: Change of color is a cheap and effective technique for lowering
Indoor temperatures. Colors having low absorptivity should be used to paint the external surface. Darker shades should be avoided for surfaces exposed to direct solar radiation. The surface of the roof can be of white broken glazed tiles (china mosaic flooring). The surface of the wall should preferably be textured to facilitate self-shading.
Remarks: As the winters in this region are uncomfortably cold, windows should be designed such that they encourage direct gain during this period. Deciduous trees can be used to shade the building during summer and admit sunlight during winter. There is a general tendency to think that well-insulated and very thick walls give a good thermal performance. This is true only if the glazing is kept to a minimum and windows are well-shaded, as is found in traditional architecture.
However, in case of non-conditioned buildings, a combination of insulated walls and high
Percentage of glazing will lead to very uncomfortable indoor conditions. This is because the building will act like a green house or oven, as the insulated walls will prevent the radiation admitted through windows from escaping back to the environment. Indoor plants can be provided near the window, as they help in evaporative cooling and in absorbing solar radiation. Evaporative cooling and earth-air pipe systems can be used effectively in this climate. Desert coolers are extensively used in this climate, and if properly sized, they can alleviate discomfort by as much as
90%.
• Warm and humid
The warm and humid climate is characterized by high temperatures accompanied by very
High humidity leading to discomfort. Thus, cross ventilation is both desirable and essential.
Protection from direct solar radiation should also be ensured by shading.
The main objectives of building design in this zone should be:
(A) Resist heat gain by:
• Decreasing exposed surface area
• Increasing thermal resistance
• Increasing buffer spaces
• Increasing shading
• Increasing reflectivity
(B) To promote heat loss by:
• Ventilation of appliances
• Increasing air exchange rate (ventilation) throughout the day
• Decreasing humidity levels
The general recommendations for building design in the warm and humid climate are as follows:
(1) Site
(a) Landform: The consideration of landform is immaterial for a flat site. However, if there
are slopes and depressions, then the building should be located on the windward side or crest to take advantage of cool breezes.
(b) Waterbodies: Since humidity is high in these regions, water bodies are not essential.
(c) Open spaces and built form: Buildings should be spread out with large open spaces for
Unrestricted air movement. In cities, buildings on stilts can promote ventilation
and cause cooling at the ground level.
(d) Street width and orientation: Major streets should be oriented parallel to or within 30º of the prevailing wind direction during summer months to encourage ventilation in warm and humid regions. A north-south direction is ideal from the point of view of blocking solar radiation. The width of the streets should be such that the intense solar radiation during late morning and early afternoon is avoided in summer.
(2) Orientation and planform
Since the temperatures are not excessive, free plans can be evolved as long as the house is under protective shade. An unobstructed air path through the interiors is important. The buildings could be long and narrow to allow cross-ventilation. For example, a singly loaded corridor plan (i.e. rooms on one side only) can be adopted instead of a doubly loaded one. Heat and moisture producing areas must be ventilated and
Separated from the rest of the structure (Fig. 5.21) [8]. Since temperatures in the shade are not very high, semi open spaces such as balconies, verandahs and porches
can be used advantageously for daytime activities. Such spaces also give protection from rainfall. In multistoreyed buildings a central courtyard can be provided with vents at higher levels to draw away the rising hot air.
(3) Building envelope
(a) Roof: In addition to providing shelter from rain and heat, the form of the roof should be planned to promote air flow. Vents at the roof top effectively induce ventilation and draw hot air out. As diurnal temperature variation is low, insulation does not provide any additional benefit for a normal reinforced cement concrete (RCC) roof in a non-conditioned building.
However, very thin roofs having low thermal mass, such as asbestos cement (AC) sheet roofing, do require insulation as they tend to rapidly radiate heat into the interiors during
daytime.
Fig- Padmanabhapuram Palace
A double roof with a ventilated space in between can also be used to promote air flow.
(a) Walls: As with roofs, the walls must also be designed to promote air flow. Baffle walls, both inside and outside the building can help to divert the flow of wind inside .They should be protected from the heavy rainfall prevalent in such areas. If adequately sheltered, exposed brick walls and mud plastered walls work very well by absorbing the humidity and helping the building to breathe. Again, as for roofs, insulation does not significantly improve the performance of a non-conditioned building.
(b) Fenestration: Cross-ventilation is important in the warm and humid regions. All doors and windows are preferably kept open for maximum ventilation for most of the year. These must be provided with venetian blinds or louvers to shelter the rooms from the sun and rain, as well as for the control of air movement.
Openings of a comparatively smaller size can be placed on the windward side, while the corresponding openings on the leeward side may be bigger for facilitating a plume effect for natural ventilation. The openings should be shaded by external overhangs. Outlets at higher levels serve to vent hot air. A few examples illustrating how the air movement within a room can be better distributed, are shown in figures below-
(c) Color and texture: The walls should be painted with light pastel shades or whitewashed, while the surface of the roof can be of broken glazed tile (china mosaic flooring). Both techniques help to reflect the sunlight back to the ambient, and hence reduce heat gain of the building. The use of appropriate colors and surface finishes is a cheap and very effective technique to lower indoor temperatures. It is worth mentioning that the surface finish should be protected from/ resistant to the effects of moisture, as this can otherwise lead to growth of mould and result in the decay of building elements.
Remarks: Ceiling fans are effective in reducing the level of discomfort in this type of climate. Desiccant cooling techniques can also be employed as they reduce the humidity level. Careful water proofing and drainage of water are essential considerations of building design due to heavy rainfall. In case of air-conditioned buildings, dehumidification plays a significant role in the design of the plant.
Figure 13 Traditional Kerala house
Parameters for sustainability in Warm and Humid Climate
Ecological Site planning The house is generally designed in response to ecology-the backwaters, plantations etc. allowing the building to effortlessly blend in to the landscape of coconut, palm and mango trees etc.
The house is divided in to quarters according to “Vastu Shastra”. It is generally desirable to build the house in the south west corner of the north-west quadrant. The south east corner is reserved for cremation purposes while the north-east corner has a bathing pool.
Local Materials The building is made from locally available stone and timber and terracotta tiles for roof.
Physical Response to climate The plan is generally square or rectangular in response to the hot and humid climate. The central courtyard and the deep verandas around the structure ensure cross ventilation. The south west orientation of the house prevent harsh sun rays from penetrating the house. Sloping roofs designed to combat heavy monsoon of the region. The overhanging roofs with projecting caves help to provide shade and cover up the walls from the rain.
Embodied energy The building use materials like Stone and timber which are a reservoir of embodied energy and have the potential to be recycled or reused.
Socio-Economic Adaptability Toilets have been integrated into the design of the house and RCC (Reinforced cement concrete) has been introduced to build houses with larger spans.
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