Green Building is generally defined as a building, which utilizes less external energy and is capable of producing ample amount of energy for its intended use itself without causing harm to the environment. Green Building is called energy efficient building or eco-friendly building. These buildings are called green due to their similarity with trees, as trees generate their food only by the use of sun light and air, these buildings are also capable of producing energy and utilizing it properly without damaging the environment.
A Green Building depletes the natural resources to the minimum during its construction and operation. The aim of a Green Building design is to minimize the demand on non-renewable resources, maximize the utilization efficiency of these resources, when in use and maximize the reuse, recycling and the utilization of renewable resources. It maximizes the use of efficient building materials and construction practices; optimizes the use of on-site sources and sinks by bio-climatic architectural practices; uses minimum energy to power itself; uses efficient equipment to meet its lighting, air-conditioning and other needs; maximizes the use of renewable sources of energy; uses minimum energy to power itself; uses efficient waste and water management practices; and provides comfortable and hygienic indoor working conditions.
It is evolved through a design process that requires all concerned elements such as the architect and landscape designer and the air conditioning, electrical, plumbing, energy consultants to work as a team to address all aspects of building and system planning, design, construction and operation. They critically evaluate the impacts of each design decision on the environment and arrive at viable design solutions to minimize the negative impacts and enhance the positive impacts on the environment. Buildings have extensive direct and indirect impacts on the environment. During their construction, occupancy, renovation, repurposing and demolition, buildings use energy, water and raw materials, generate waste and emit potentially harmful atmospheric emissions. These facts have prompted the creation of green building standards, certifications and rating systems aimed at mitigating the impact of buildings on the natural environment through sustainable design.
Concept of Green Building
A green building is an environmentally sustainable building, designed, constructed and operated to minimize the total environmental impacts. The general perception as regards the green building is that they cost more but in reality, is that many green strategies and technologies actually cost the same and some even cost less than traditional ones. The basic idea behind the green building is to carve out fine techniques and skills to bring down the effect on the environment and human health to a lesser degree and by promoting the optimal use of renewable resources, e.g., using sunlight through passive solar, active solar and photovoltaic equipment and using plants and trees through green roofs, rain gardens and reduction of rainwater wastage. It lays emphasis on the energy efficiency and conservation, water and air quality by a careful designing. Green building concept is popularly known as “Sustainable Architecture”, and “Ecological Design” because of basing upon the idea of sustainable development.
Green buildings have only been building up by individuals and companies for the past thirty years. During the energy crisis of the 1970’s, green building moved from research and development to reality. Green measures can help in improving the ecological environment and helps in reducing energy uses by at least 30-35%, carbon emission by 35% and wastages by 70% and use of water by more than 40%. On the aesthetic side of green architecture or sustainable design is the philosophy of designing a building that is in harmony with the natural features and resources surrounding the site. There are several key steps in designing sustainable buildings: specify green building materials from local sources, reduce loads, optimize systems, and generate on-site renewable energy.
Global warming and climate changes have become a major concern for mankind today. In order to ensure that, development and environment conservation go hand in hand, major corporations around the world are empowering projects to slow down depletion of natural resources. We spend 90% of our lives in buildings that protect us from the extremes of the nature like heat, cold, rain, wind, snow etc. Buildings use enormous amount of energy, water and material throughout their life cycle. They also create a large amount of waste and have a profound effect on ecosystem. The economic, health and environmental impact of our homes is apparent in our society. To meet the challenges of our built environment, a new way of designing and construction has evolved.
The technique associated with the ‘Green Building’ include measures to prevent erosion of soil, rainwater harvesting, use of solar energy, preparation of landscapes to reduce heat, reduction in usage of water, recycling of waste water and use of world class energy efficient practices. It can also be adopted for the entire side. Such as using good landscaping or predicting and usage of solar energy and preventing from soil erosion and using reduced amount of water and recycling of waste water etc. A similar concept is natural building, which is usually on a smaller scale and tends to focus on the use of natural materials that are available locally.
History
The push toward sustainable design increased with the launch in 1990 of Building Research Establishment's Environmental Assessment Method (BREEAM), the first green building rating system in the world. In 2000, the U.S. Green Building Council (USGBC) followed suit and developed and released criteria also aimed at improving the environmental performance of buildings through its Leadership in Energy and Environmental Design (LEED) rating system for new construction. Since that first release, LEED has continued to grow in prominence and to include rating systems for existing buildings and entire neighbourhoods.
Others also responded to the growing interest and demand for sustainable design including the Green Building Initiative (GBI), which was created to assist the National Association of Homebuilders (NAHB) in promoting its Green Building Guidelines for Residential Structures. Although originally developed for Canada, GBI helped to make Green Globes available for use in the U.S. in 2005. Additional rating systems have been developed that were influenced by these early programs but are tailored to their own national priorities and requirements or seek to go beyond the limits of current policy and building practices to address broader issues of sustainability or evolving concepts such as net zero energy and living and restorative building concepts that improve the natural environment or those that model nature's processes.
Features of Green Building
During the construction and operation, it minimizes the demand on fossil fuel based energy, maximizes the recycle, reuse, renewable energy and energy efficient devices and appliances. It utilizes energy efficient building materials, besides taking care of water conservation, waste management, energy conservation etc. Green buildings promote the use of renewable energy systems i.e. solar water heating systems, rooftop PV system, waste recycling for energy generation etc. The overall sustainable mechanism of construction industry depends upon various factors. The consideration of natural/ecological concerns primarily measures the green performance rating of a building. Green performance of a building is based on broadly five key parameters i.e. sustainable site, water efficiency, energy, materials and atmosphere.
1) Energy Efficiency
Green buildings designs are prepared in such a manner as the energy requirement in a building could be minimized to a maximum extent. Keeping the same objective in mind, the designers often suggest measures like sensors, ventilation, high-performance windows and extra insulation in walls, ceilings and floors. They orient windows and walls and place trees to shade windows and roofs during the summer while maximizing solar gain in the winter. Apart from this all, utmost attention is given for the use of renewable energy and effective window placement to ensure natural light. Emphasis is also given for onsite generation of renewable energy through solar power, wind power, hydro power or biomass so as to reduce the environmental impact of the building.
2) Water Efficiency
An attempt is to be made to reduce the consumption of water as the availability of fresh water is limited on the earth. Therefore, at water-scarce places, the used water is collected, used, purified and reused on-site itself. Waste water may be minimized by utilizing water conserving fixtures such as ultra-low flush toilets and low-flow shower heads. Moreover, it is believed that preserving existing forest and mature vegetation in the nearby area play a pivotal role in the natural water cycle by absorbing and disbursing up to 30% of a site’s rainwater through evapo-transpiration.
3) Indoor Environmental Quality
It is needless to mention that without ensuring good indoor air quality, proper ventilation, natural vegetation, a healthy life is not possible for the residents in any building. While constructing a building, it should always be kept in mind that biodegradable and environment-friendly materials should be used so that they could not give rise to health hazards.
4) Sustainable Site Design
The selection of a sustainable site plays a vital role to make the idea of green building a great success. As we all know that the land is non-expandable. Therefore, a careful designing, in this regard, helps to have green space so as to make the life healthier and lively. Higher density urban development and urban renewal needs to be promoted at a large scale.
5) Materials and Resources
Bearing this fact in mind that natural resources are not unlimited therefore, the techniques for recycling and reuse should be taken into consideration. The use of renewable and sustainable materials needs to be utilized to a great extent. This method serves the dual purpose i.e. firstly, useful from the occupant’s point of view and secondly, not harmful for the nature point of view also.
