The main function of buildings is to provide a comfortable indoor environment and to protect the mankind from the extremities of climates. The entire history of shelter engineering reveals the unremitting effort of the human race to find adequate building designs to which man is best adapted. Traditional buildings, therefore, were built with considerations to climatic conditions for keeping the inside building spaces cool in summer and warm in winter. Red fort and other forts in Rajasthan are few to example. These aspects have been forgotten in the modern architecture, which essentially relies on mechanical methods of heating and cooling involving large amount of energy expense. The construction sector poses a major challenge to the environment. Globally, buildings are responsible for at least 40% of energy use.
A growing world-wide concern for the conservation of energy and depletion of natural resources there is a renewed interest in those aspects of architecture, which leads to thermal comfort in buildings with minimum consumption of conventional energy. These aspects are termed as energy efficient design strategies. Various energy efficient strategies for heating and cooling of the buildings are (i)Building design parameters viz. Orientation, reflecting components, absorbing surfaces, glazing, minimum surface to volume ratio, thermal insulation, reduction of air infiltration, shading, air cavities etc. and (ii) Efficient selection of HVAC equipments. As we chart our development path, it is important for us to keep our eyes on the environmental damage that we create. It is extremely important to pause for a while and carry out necessary courses correction for benefit. It is well established fact that green buildings offer immense potential to reduce consumption and regenerate resources from waste and renewable sources.
A green building depletes the natural resources to a minimum during its construction and operation. The aim of a green building 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 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 bioclimatic architectural practices, uses minimum energy to power itself, uses efficient to meet its lighting, air conditioning and other needs, maximizes the use of renewable sources of energy, uses efficient waste and water management practices and provide comfortable and hygienic indoor working conditions.
Buildings, as they are designed and used today, contribute to serious environment problems of excessive consumption of energy and other natural sources. The close connection between energy use in building and environmental damage arises because energy-intensive solution sought to construct and meet its demand for heating, cooling, ventilation, and lighting cause severe depletion of invaluable environment resources. However, building can be designed to meet the occupant’s need for thermal and visual comfort at reduced levels of energy and resources consumption. The primary steps in this approach are listed below.
- Incorporate solar passive techniques in a building design to minimize load on convention system (heating, cooling, ventilation, and lighting).
- Design energy-efficient lighting and HAVC (heating, ventilation, and air-conditioning) system.
- Use renewable energy systems (solar photovoltaic system/solar water heating system) to meet part of building load.
- Use low energy materials and method of construction.
Thus in brief, an energy-efficient building balances all aspect of energy use in building-lighting, space-conditioning, and ventilation-by providing an optimized mix of passive solar design strategies, energy-efficient equipment, and renewable sources of energy. Use of materials with low embodied energy also form a major component in energy-efficient building designs.