The Concept of Green Buildings within India

Cities cover less than 50% of the earth’s surface but are disproportionately responsible for causing climate change. Currently, around 50% of the world’s population lives in cities. Until 2030, 60% of the world’s population growth will occur in cities. Cities and urban areas consume some 75% of the world’s energy and are responsible for up to 75% of greenhouse gas emissions. Cities directly or indirectly account for 60% of world’s water use. So, a majority of the world’s energy consumption either occurs in cities or as a direct result of the way that cities function. A study recently conducted showed that more than half of the reduction potential lies within buildings. Making existing and new buildings to Green Buildings is one of the most effective levers to meet the challenges of CO₂ reduction in cities.

A Green Building is an outcome of a design which focuses on increasing the efficiency of resource use – energy, water, and materials – while reducing building impacts on human health and the environment during the building’s lifecycle, through better siting, design, construction, operation, maintenance and removal. Green Buildings can have tremendous benefits, both tangible and intangible. The most tangible benefits are the reduction in water and energy consumption right from day one of occupancy.

The energy savings could range from 20 – 30% and water savings around 30 – 50%. Intangible benefits of Green Buildings include enhanced air quality, excellent day lighting, health & wellbeing of the occupants, safety benefits and conservation of scarce national resources.

The concept of Green Building has evolved to create environmentally sound buildings and reduce the overall impact on human health. Green buildings are designed to efficiently use energy, water and other natural resources to create a health conducive indoor and reduce the overall impact on the environment as well as non-renewable natural resources.

To define Green Building and establish a common standard of measurement in India, the IGBC (Indian Green Building Council) developed Green Building Rating System from the LEED (Leadership in Energy and Environmental Design) Rating System. In addition, IGBC promotes whole building design practices, recognizes environmental leadership in the building industry, stimulates green competition, raises consumer awareness of green building benefits and transforms the building market into a more environmentally responsible entity. So, in this report the IGBC Green Building Rating System has been discussed.

IGBC Green Building Rating System addresses green features under the following categories: Site Selection and Planning, Water Efficiency, Energy Efficiency, Materials, Indoor Environmental Quality, Innovation & Design Process. Methods and techniques under these categories have been discussed.

Case study on few famous green buildings is also presented. The Green Buildings Paradigm in India has been covered briefly. Cities account for 75% of world energy and emits 75% of greenhouse gases. Adopting the “Green Building” concepts can effectively reduce energy consumption and better use of natural resources.

Concept of Green Buildings

Green building does not mean that the building is painted green, but building that has incorporated nature-friendly features. Green represents nature. Green building is the practice of increasing the efficiency with which buildings use resources – energy, water, and materials – while reducing building impacts on human health and the environment during the building’s lifecycle, through better siting, design, construction, operation, maintenance, and removal. Green buildings are designed to reduce the overall impact of the built environment on human health and the natural environment by:

• Efficiently using energy, water, and other resources
• Protecting occupant health and improving employee productivity
• Reducing waste, pollution and environmental degradation

Effective green building can lead to

• Reduced operating costs by increasing productivity and using less energy and water,
• Improved public and occupant health due to improved indoor air quality, and reduced environmental impacts by, for example, lessening storm water runoff And the heat island effect, etc.

In short, ‘a Green Building should create delight when entered, serenity and health when occupied and regret when departed‘.

Energy efficient and environment conscious building design is essentially an integrated approach. The available options in architectural intervention, building materials and design methodologies need to be carefully evaluated to minimize energy usage, minimize the ecological degradation that may be caused by the construction of the building and provide cost effective solutions. The aim is to achieve the desired comfort with the least input of conventional energy.

Though the rules are not very well defined, architects and designers accomplish the task through solar passive design, use of renewable energy technology systems, and/or natural building materials. While designing such buildings, not only new building stock can be targeted but also existing buildings can be retrofitted with energy efficient and eco-friendly technologies, thereby substantially reducing energy consumption.

• A green building depletes the natural resources to the minimum during its construction and operation.
• Main aim is to minimize the demand on non-renewable resources and maximize the utilization efficiency of these resources.
•  Maximize the reuse, recycle and utilization of renewable resources.
•  Optimize the use of on-site resources sinks by bio-climatic architectural practices.
•  Use efficient equipment to meet its lighting, air condition and other needs.
• Use efficient waste and water management practices.
• Provide comfortable and hygienic indoor working conditions.

In sum, the following aspects of building design are looked into in an integrated way in a green building:

• Site planning
• Building envelope design
• Building system design (HVAC, i.e, heating, ventilation and air conditioning, lighting, electrical and water heating)
• Integration of renewable energy resources to generate energy on site
• Water and waste management
• Selection of ecologically sustainable materials (with highly recycled content, rapidly renewable resources with low emission potential, etc.)
• Indoor environmental quality

Problems in conventional buildings

All over the world we are finally beginning to recognize the threat that building construction is posing to the civilization. Buildings have major environmental impacts over their life cycle. There are various problems arising in the present scenario.

Conventional buildings pollute

• Buildings contribute 40-50% of Greenhouse Gas (GHG) emissions.
• Buildings create 65% of all solid waste, 90-95% of construction and demolition waste could be recycled.
• Indoor pollution often 2-100 times worse than outdoors.

Advantages of green buildings (Fig. 1):

• By using toxin-free building materials, they lower indoor pollution. Also, they provide better ventilation and natural light.
• They use locally available materials. Also, they use renewable sources of power like solar, hydro and wind.
• They provide improved air and water quality with reduced carbon emissions.

Essential criteria (Fig. 2) to make a building green

• Sustainable site design: Preserve key environmental elements to create a minimum urban spread and minimize needless destruction of urban land.
• Water quality and conservation: Preserve the natural water cycle of the area. Develop and implement water harvesting to minimize dependence on local supply.
• Energy and environment: Maximize use of renewable energy and other low impact energy sources. Building performance should exceed the minimum International Energy Code (IEC) compliance level by 30-40%.
• Indoor environmental quality: utilize best possible conditions in terms of indoor air quality, ventilation, thermal comfort, access to natural ventilation, and day lighting.
• Materials and resources: Maximize the use of recycled materials and resource efficient composite type structural as well as sustainably managed, biomass materials.

Economic benefits

Considerable research and analysis has been carried out with regards to the cost impacts of a green building. The cost could be slightly higher than conventional building. But then, this need to be seen in a different paradigm. The question is how do we compare the cost? There needs to be a baseline cost for all comparisons to be alike. The incremental cost is always relative and depends on the extent of eco-friendly features already considered during design. The incremental cost would appear small if the baseline design is already at a certain level of good eco-design; it would appear huge if the base design has not considered green principles. The second and rather critical paradigm is to look at the incremental cost in relation to the life cycle cost. This kind of an approach could be revealing. Who knows, whether a building would last for 50 years or 60 years or 100 years? Over its life cycle, the operating cost would work out to 80-85% while the incremental cost which is one-time cost is only about 8-10%.

Layout of green buildings

The key to energy efficiency in green buildings is to have a comprehensive integrated perspective during the design phase (Fig. 3) that seeks to reduce heating, cooling, and lighting loads through taking advantage of the building site and climate attributes. Include passive solar design and integrated landscape design that use trees for shading, windbreaks, and attractive outdoor spaces. Research and include renewable energy sources such as day lighting, passive solar, solar thermal (hot water) and photo volts, and geothermal heating and cooling.

Use of renewable energy increases energy security and reduces dependence on fossil fuels. Use project specifications to lay the groundwork for energy efficiency, specifically stating project goals, targets, and strategies for energy efficiency. Specify energy efficient HVAC equipment that meet or exceed federal, state, and local standards, such as LEED, Energy Star, or other federal or state high-performance mandates.

Increase building performance by including predictive energy models and system controls, such as occupancy and daylight sensors, CO₂ sensors and other air quality alarms. Employ sensors that control loads based on occupancy and availability of natural resources such as daylight or natural ventilation. Use energy management tools to track energy and water use such as the Energy Star Portfolio Manager. Integrate water saving technologies that reduce the energy burden that comes along with providing potable water such as Water Sense fixtures and rainwater harvesting practices.

Orientation to the sun to take advantage of passive solar heating and lighting to build an energy efficient structure, creating a well-insulated envelope that requires less energy to heat and cool. Low E windows to prevent the loss of heat, green materials, lumber from sustainable forestry practices, material that emit low toxins, recycled materials and water saving faucets, use of advanced energy systems geothermal heating/cooling masonry heater, photovoltaic cells, solar hot water and wind turbines.

Conclusion

The concept of a green building is not new but has certainly gained momentum in the past few years. Exhaustion of natural resources, pollution, and rapid globalization has harmed our environment; we must construct more green buildings in India to preserve and conserve whatever is left.

According to Indian Green Building Council (IGBC), India has achieved 7.17 billion sq ft of Green Building Footprint. As per Leadership in Energy & Environmental Design (LEED), Maharashtra ranks first in green buildings in India, followed by Karnataka, Haryana, Tamil Nadu and Uttar Pradesh.

Dr. (Prof.) D.B. Jani received Ph.D. in Thermal Science (Mechanical Engineering) from Indian Institute of Technology (IIT) Roorkee. Currently he is a recognized Ph.D. Supervisor at Gujarat Technological University (GTU). Published more than 200 Research Articles in reputed International Conferences and Journals. He has also published 8 reputed books and book chapters in the area of thermal engineering. Presently, he is an Associate Professor at GEC, Dahod, Gujarat Technological University, GTU, Ahmedabad (Education Department, State of Gujarat, India). His area of research is Desiccant Cooling, ANN, TRNSYS, and Exergy.