The Economic Feasibility of Green Roof construction in Hyderabad, India.By : Harish Vangara
MA Thesis, Landscape Architecture, The University of Sheffield
Abstract:
Green roof technology is the main trend in today‟s times of growing economy and changing global conditions, be it about global warming, ocean pollution, air pollution, deforestation and endangered evaporating water. One m2 of plants can evaporate 0.5 Litres of water on a summer day and accordingly annually, the same area can evaporate up to 700 Litres of water.
This phenomenon reduces the “Urban Heat Island Effect” in summer. This UHI effect is basically the difference between temperatures of a city and the surrounding country side. The main reason being the radiating heat of hard materials like concrete and hard surfacing such as roofs which absorb heat and re-radiate it as heat reduction of UHI effect will considerably reduce the dust distribution and production of smog, which finally reduces the green house gas emissions and adapting urban areas with warmer summers in the future.
Green roofs cannot deal with all the above factors, but can have a mitigating effect on some of them, like reducing carbon emissions, reducing storm water runoff (Bengtsson 2002) and mitigating urban heat island effects (Akbari et al. 2001) and keeping building temperatures low in summer (Eumorfopoulou & Aravantinos 1998; Onmura et al. 2001). Green roofs also improve urban biodiversity (Mann 1998; Brenneisen 2003). This technological trend had been started by Germans from the 1960s and the Americans and Europeans have widely been following this ever since. Today an estimate of 10% of roofs has been greened. Major cities and growing economies like Japan and China have also been looking into this in detail. Cities in India have a good scope for this science.
Hyderabad, (India) has a tropical wet/dry climate with hot summers between March and June, the damp monsoon season between July and October and mild, dry winter between November and February. It has an average annual rainfall of 810 mm every year, and the maximum temperature recorded was 45.5 oC.
Green roofs are not a common feature in Indian cities as they are in the United States and in Europe, because they are not very well understood.
Green building technologies have started to consider this technology as a must for lessening the adverse effects for environmental contribution.
This study investigates the benefits of green roofs on building rooftops and some case studies comparing it with European climates. An analysis is made how feasible it has been, for the conditions in Hyderabad and observing how this can be practically made possible.
Perhaps this can be promoted by architectural and landscape firms to create awareness of green roofs and its advantages.
The main aim of this research is to see how a green roof can be built economically considering the climatic facts for urban-central property in Hyderabad.
