low energy traditional architecture of lucknow

LOW ENERGY TRADITIONAL ARCHITECTURE OF LUCKNOW Dr. Mohammad Arif Kamal (Lecturer) Department of Architecture Aligarh Muslim University Aligarh (INDIA)

Dr. Najamuddin (Professor Emeritus) Department of Architecture and Planning Indian Institute of Technology, Roorkee Roorkee, (INDIA)

INTRODUCTION Buildings, as they are designed and used today, contribute to serious environmental problems because of excessive consumption of energy and other natural resources. The close connection between energy use in buildings and environmental damage arises because energy intensive solutions sought to construct a building and meet its demands for heating, cooling, ventilation, and lighting, which causes severe depletion of invaluable environmental resources. The continuous increase in the consumption of energy is not only consuming an unsustainable amount of fossil fuel but it also delivers huge amounts of air pollution, which is linked to the global warming and green house effect resulting in ozone depletion. Rapoport mentions in his book House, Form and Culture that the need of shelter design adapts and responds to the severity of the climate in the area. It is this intuitive adaptive capability to respond to the forces of climate like sun, wind and humidity that sets apart bioclimatic architecture from senseless, arrogant, and merely style-based creation (Rapoport, 1969). The traditional buildings of the past have inbuilt thermal comfort property and were based on climate responsive integrated passive design approach and hence constitute outstanding examples of being energy conscious buildings. The traditional houses of Lucknow, which is the context of my study, were also built much before innovations in mechanically controlled interior environment. In this paper the climate responsiveness and appropriateness of the traditional residential buildings in old settlement of Lucknow, a North Indian town has been analyzed. LUCKNOW: THE RESEARCH CONTEXT The city of Lucknow is situated on the banks of river Gomti. It is the capital of Uttar Pradesh, the most populous state of India. Lucknow is a historical city of Nawabs, and is famous for its Nawabi culture, traditions and rich architectural heritage. The Nawabs of Lucknow not only built fine structures in traditional styles and experimented in European ones, but also created a novel hybrid style, which was an amalgamation of both Mughal- Islamic and European elements (Tandan, 2001). Climate of Lucknow Lucknow has a composite climate, which can be identified four main seasons, the summer, which is hot and fairly dry, the monsoon, which is less hot but humid, a period of moderate temperatures and humidity, and a slightly cold winter period. The climatic data of last twenty years published by the Central Building Research Institute, Roorkee is summarized below: (CBRI, 1969) Temperature - The monthly mean maximum temperature during the hottest month (May) is 44.2°C and the monthly mean minimum temperature during the coldest month (Jan) of the year is 8.9°C.

Relative Humidity - The relative humidity during summer can be less than 25% and during the most humid months the relative humidity is in the range of 78% to 82%, whereas the air temperature is in the range of 32.5°C to 34°C. Rainfall - The rainfall starts with the arrival of the Monsoon in the middle of June. The regular rainy season continues up to the middle of September. The total annual rainfall is 940 mm. Wind - The wind speed is in the range of 3.4 to 5 km / hour from May to September. The predominant wind direction is east. THERMAL PERFORMANCE OF TRADITIONAL HOUSES The study hypotheses that the traditionally constructed and designed houses are considered to be more climate responsive as compared to the modern houses. The research involves the study of thermal performance through on-site monitoring of two traditional houses and one modern dwelling unit of Lucknow. Both quantitative and qualitative methods of gathering data were used. These included (a) Recording of the physical form and construction systems of the buildings and settlements. (b) Recording the thermal performance in all the three buildings during the period of climatic extremes. The temperature and relative humidity were measured outside the building and in different indoor spaces for every two hours for a complete one-day cycle for each building with the help of digital thermo hygrometer. (c) Comparative analysis of the thermal performance of the buildings. Case study 1: Rizvi house This is a traditional courtyard house in Chowk at Lucknow, built around 1915 to serve the purpose of 'Janana Imambara' or ladies mourning place (Fig.1). The mourning still takes place at the time of Moharram (first month of Islamic calendar) in the Majlisi or the ‘mourning hall’ and for the rest of the time of the year the Majlisi is used as a living room. It is double storey building with a small central courtyard of dimension 7.05m X 6.4m surrounded by living rooms on three sides and entrance on the north side (Fig.2). The Majlisi is a double height hall, which opens to three imambaras in the front and two mosques at both level on its right and a room on its left (Fig. 3).

Fig. 1 View of Rizvi House

Fig. 2 View of Courtyard

Fig. 3 Double Height Majlisi

Features of Rizvi House The building is slightly shifted towards west maintaining the NE-SW orientation (Fig. 4). The maximum openings and the entrance are on the NE side i.e. the windward direction. There are few openings on south east side and no openings on southwest side. The absence of the openings on exterior surfaces helps in reducing heat gains. The main entrance opens into the narrow shaded street, which induces cool air from the street into the building. The courtyard facilitates shaded spaces and facilitates ventilation in the interiors through the openings facing the courtyard. The projection of eaves in the courtyard provides shade from direct solar radiation into the rooms, which opens into the courtyard. The jharokhas on the northern face of the building catch prevailing wind and hence provides air circulation into the rooms at first floor. The masonry walls are 0.45m thick constructed with lakhori bricks and finished with lime plaster. The roof is 0.35m thick constructed of

jack arch with lakhori bricks on steel girders and finished with lime concrete. The massive walls and heavy roofs offer greater thermal resistance and hence increase the time lag. The exterior of the building is white washed which helps in reflecting solar radiation.

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Fig 4 Ground floor plan and first floor plan of Rizvi House

Rizvi House (Summer)

Rizvi House (Winter)

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Fig. 5 Summer and winter temperature profile of Rizvi House. Case Study 2: Qaiser Jahan House This is a courtyard house of late Mrs. Qaiser Jahan Begum in Nakkhas at Lucknow, which is around 125 years old. The entrance of the house opens into a narrow street (Fig. 6). There is an entrance lobby, which opens directly into the courtyard. The square shaped courtyard of dimensions 10.75m X 10.0m is centrally located, enclosed by rooms on three sides and an entrance on the west side. The eastern side of the courtyard has a double height hall (Fig. 7) and on the other three side of the court are single height structures. The double height hall opens into an Imambara and two bedrooms. This double height hall is also used as a ‘majlisi’ or mourning place during Moharram. On the north side of courtyard is the kitchen, a bathroom and a toilet and on the southern side of the courtyard are two living rooms.

Fig. 6 Entrance opening in a narrow street

Fig. 7 Double Height hall with timber ceiling

STORE 2.4m x 3.0m

STORE 2.4 x 3.0m

IMAMBARA

BED ROOM 2.4 x 3.75m

DOUBLE HT. HALL (MAJLISI) 10.75 x 3.85m

W.C. 2.4 x 2.25m

BED ROOM 2.4 x 3.75m

ROOM 2.4 x 4.0m

BATH 2.4 x 1.5m

COURT YARD 10.75 x 10.45m KITCHEN 2.4 x 3.45m

STUDY 2.4 x 3.45m

STORE 2.4 x 2.35m GUEST 2.4 x 5.85m

UP

BATH 2.4 x 2.9m W.C. W.C. 1x 0.95m 1x 0.95m

BED ROOM 3.65 x 2.9m ENT.

Fig. 8 Ground Floor Plan of Qaiser Jahan House Features of Qaiser Jahan House The house opens into the narrow street, which is shaded by the balcony and projections of the buildings on both sides. The entrance of a house is through a lobby, which opens into a central courtyard. As the courtyard gets heated up during the day the hotter air rises and denser, cool air, which is drawn from the shaded streets, rushes into the courtyard and hence induces ventilation in the interiors of the surrounding rooms. (Fig. 9)

Fig. 9 View of Courtyard

Fig. 10 Evaporative cooling due to vegetation

The absence of the openings on exterior surfaces helps in reducing heat gains. The double height entrance on the south west side provides shade to the building from the afternoon sun. The thickness of the wall is 0.60m and constructed of lakhori bricks finished with lime surkhi plaster. The roof is 0.45m thick constructed of brick ballast mixed with lime surkhi mortar laid on timber sheets supported by timber beams. The massive walls, heavy roof and timber ceiling offer greater thermal insulation and hence increase the time lag. The ventilators near the ceiling facilitate stack effect and extract the warm air from the rooms. There is also evaporative cooling due to vegetation in surroundings (Fig. 10). The exterior of the building is plastered with lime mortar and whitewashed, which reflects the solar radiation to some extent. There is also a reduction of heat gain by providing textural shading due to ornamentation and stuccowork on the building facade. Qaiser Jahan House (Summer)

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Fig. 11 Summer and winter temperature profile of Qaiser Jahan House. THERMAL PERFORMANCE OF MODERN HOUSE Case Study 3: LDA. House This building is a M.I.G. residence, which was built by the Lucknow Development Authority in Aishbagh, around 40 years back (Fig. 12). It is a double storey building with living room, kitchen, toilet and one bedroom on the ground floor and one bedroom and toilet on the upper floor (Fig. 13). The construction consists of 0.23m thick load bearing brick masonry walls and 0.15m thick roof. The heights of the rooms are 3.0m and openings are of dimensions 0.9m X 1.2m N

30'

REAR LAWN

FUTURE EXT.

BEDROOM 11'-0" X 18'-9"

BEDROOM 11'-0" X 18'-9" TOILET 11'-9" X 5'-0"

TOILET

60'

11'-9" X 5'-0"

DN

UP

STORE 5'-4 1/2" X 6'-0"

LIV./ DIN.

22'

11'-0" X 22'-0"

KITCHEN 6'-0" X 12'-3" OPEN TERRACE

PORCH

VERANDAH

8'

Temperature (Deg. Cent.)

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Fig. 12 View of L.D.A. House

FRONT LAWN

Fig. 13 Ground and First Floor Plan of L.D.A. House

Features of L.D.A. House This is a semi detached house and it is compactly planned residence with a small front and rear yard. There are only few openings, which opens into the front and rear yard, which obstructs the free movement of the air and does not provide cross ventilation. The living room is located on the western side without proper shading, which causes discomfort in summers. The roof of the first floor is 0.10m thick R.C.C. construction finished with small brick ballast and cement sand mortar. The roof is a major source of heat gain for the upper floor due to absence of appropriate terracing. There is no proper projection on openings and on the terrace level on south and west side to shade the walls on first floor. This causes the walls to heat up and hence permits the heat into the rooms through conduction. The plastered exterior surface with whitewash reflects solar radiation to some extent. L.D.A. House (Summer)

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. Fig. 14 Summer and winter temperature profile of L.D.A. House. INFERENCES 1. The data collected shows that the indoor air temperature in the two traditional buildings is 23°C lower in summers and 2-3°C higher in winters as compared to the indoor temperatures in L.D.A house. 2. The difference between the sky and indoor temperature in traditional buildings is greater than the indoor temperature in L.D.A. house suggesting more comfort level in traditional buildings. 3. In summer the mean maximum indoor temperature of different rooms of traditional house was 10-12°C lower and mean minimum temperature was 3-4°C higher than the outdoor minimum temperature whereas in L.D.A. house the mean maximum indoor temperature was 5-6°C lower and mean minimum temperature was 7-8°C higher than the outdoor minimum temperature. 4. In traditional houses, the amplitude of indoor air temperature was not more than 4-5°C while the outdoor temperature fluctuation was of the order of 18-20°C. 5. In winter, in traditional houses there was 4-5°C temperature difference between mean maximum indoor temperature of different rooms and maximum outdoor temperature and 56°C temperature difference between mean minimum indoor temperature and the minimum outdoor temperature whereas in L.D.A. house there was difference of 8-9°C between mean maximum indoor temperature of different rooms and maximum outdoor temperature and 45°C temperature difference between mean minimum indoor temperature and minimum outdoor temperature. 6. The courtyard system in traditional buildings ensured ventilation through the building even during the periods when the outdoor conditions were calm. The courtyard temperature was

1-2°C higher in late afternoons and 2-3°C lower in early morning as compared to the indoor temperatures of the rooms. 7. The areas of the building directly exposed to the sun were 2-3°C higher in traditional buildings due to thick massive walls whereas in L.D.A. house it was at times 7-9°C higher than the corresponding ambient air temperature. CONCLUSIONS The use of natural and passive means in traditional houses of Lucknow was very effective in providing a thermally comfortable space, which was warm in winter and cool in summer. In Lucknow, the buildings are clustered together, separated only by narrow shaded streets. The street orientation ensures that the building facades are either shaded by overhangs, balconies, jharokhas, chajjas projections, or by the opposite building. Due to the shadow patterns, the building receives minimum radiation from direct solar exposure, which results in reducing peak heat flux into the building. The greater ceiling height increases the volume of the enclosed space, taking more time for the internal air to get heated up. The verandah served as a buffer space between the interiors and the outside environment. There is a time lag due to thick masonry wall and heavy roof construction system found in traditional houses of Lucknow. The courtyard system ensures ventilation through the building even during the calm outdoor conditions. The openings such as windows, ventilators and skylight provided cross ventilation, by creating stack effect. The ventilation apertures such as jharokhas, jaalis induces forced ventilation into the interiors of the buildings. The vegetation near the vicinity of the building reduces the heat gain by shading the building from direct solar radiation and cooled the interiors by evapotranspiration. It is clear from the study that an appropriate use of materials, spatial organization, construction techniques and passive design features could bring about the much-desired comfortable environment inside the house. The principles of good thermal design used in traditional buildings are still valid today and it would still be possible for modern designers and architects to incorporate these design principles in buildings, which are suitable for modern day living to conserve energy and provide better thermal comfort. Incorporation of such techniques would certainly enhance the energy efficiency and reduce our dependency on artificial means for comfort. This would help us in reducing the energy consumption level at national and global level. Hence it is essential to take the wisdom of the past and evolve a built form, which will be more humanized, more climate responsive and more environmental friendly buildings of tomorrow. REFERENCES 1. Central Building Research Institute (1969), Climatological and Solar Data for India, Sarita Prakashan, Meerut 2. Rapoport A. (1969), House, Form and Culture, Prentice Hall Publications, New Jersey, 3. Tandan Banmali (2001), The Architecture of Lucknow and its dependencies, 1792-1856, Vikas Publishing House Pvt. Ltd., India