Dr Mukul Chandra Bora
Buildings account for one-sixth of the world’s fresh water withdrawals, one-quarter of its wood harvest and two-fifths of its material and energy flows. Buildings which are constructed by incorporating tripod of attributes – energy efficiency (both in material selection and actual energy use), healthy living including indoor air quality, and careful resource management – are termed as Green Buildings. A green building does not require any architectural style which looks visually green. It doesn’t have to be expensive to build, nor does it have to look ‘different’. It can be designed in any style, or any shape.
The main focus of a green building is to provide benefits to occupants. These include: less expensive to heat and cool, greater comfort, healthier, particularly for children, greater durability, and less maintenance. A green building, also known as a sustainable building, is a structure that is designed, built, renovated, operated, or reused in an ecological and resource-efficient manner.
Buildings are a very complex system and comprise different subsystems in which every component has got a strong interaction with the other, and hence affects the structure as a whole. Each component of building is made up of individual products, different technologies, which in turn dictate the function of the products, particularly the relationships amongst the different components. A building can be considered as an analogous system of human body. This analogy, if we can apply properly for the design and layout of building components, will make the building cause minimum or no damage to the environment and hence will be a sustainable construction. The building envelope (walls and roof) acts like the skin of the human body and hence is the most crucial part of it. It regulates the inside temperature and overall condition of the building and is directly related to its inside-outside interaction. The different elements of a Green building are described below.
The building construction site is well suited to take advantage of mass transit facilities. The natural landscaping and natural features should not be destroyed as far as possible so that the advantage out of these natural features can be explored properly. Use of plantation, which needs low water and less pesticide, is a very important component of a green building, and plants should require fewer trimmings. Organic fertilizer like compost and mulches should be used and chemical fertilizer should be avoided as far as possible.
A building consumes energy, mainly for cooling, heating and lighting. The design of a building should be such that it uses maximum available energy of the nature. Such design is termed as ‘Passive Design of a Building’. The passive design of a building can dramatically change its energy-use pattern. The measures include building shape and orientation, passive solar design, and the use of natural lighting. Studies have proved that such design has a positive impact on productivity and well being as well.
Selection of new construction materials and use of recycled and scrap materials are the two important factors for construction of green buildings. Such products promote resource conservation and efficiency. Using recycled-content products also helps in the solid waste management system. Use dimensional planning and other material efficiency strategies. These strategies reduce the amount of building materials needed and cut construction costs. Reuse and recycle construction and demolition materials. For example, using inert demolition materials as a base course for a parking lot keeps materials out of landfills and costs less.
Occupants’ Health and Safety
Research findings reported in different literatures reveal that buildings with a good overall environmental quality can reduce the rate of respiratory disease, allergy, asthma, sick building symptoms, and it enhances workers’ performance. Choose construction materials and interior finish products with zero or low emissions to improve indoor air quality. Many building materials and cleaning/maintenance products emit toxic gases, such as volatile organic compounds (VOC) and formaldehyde. These gases can have a detrimental impact on the occupants’ health and productivity. Provide adequate ventilation and a high-efficiency, in-duct filtration system. Heating and cooling systems that ensure adequate ventilation and proper filtration can have a dramatic and positive impact on indoor air quality.
Economic use of water is one of the prime criteria for green buildings. The recycled water can be used for toilet flushing or other non-potable uses like water for plants and trees. Rainwater harvesting should be opted for non-potable use for optimum use of water sources which consumes energy and causes extra heat to the environment. The green building concept of building design cannot achieve its goals unless it works as intended. Building commissioning does not merely mean testing and adjusting the mechanical, electrical, and plumbing systems to meet design criteria, but also includes instructing the staff on the operation and maintenance of equipment.
Use of Green Building Materials
The use of materials in construction should be so selected that it gives minimal environmental impact to the nature. The materials used as a green material are not necessarily green in colour, but they should have those properties which help to keep our surroundings clean and safe. Green building materials offer specific benefits to the building owner and building occupants
* Reduced maintenance/replacement costs over the life of the building
* Energy conservation
* Improved occupant health and productivity
* Lower costs associated with changing space configurations
* Greater design flexibility
Green Concrete, as the name suggests, is eco-friendly and saves the environment by using waste products generated by industries in various forms like rice husk ash, micro silica & flyash etc to make resource-saving concrete structures. Green concrete is very often also cheaper to produce as it uses waste products directly as a partial substitute for cement, thus saving energy consumption in production of per unit of cement.
Use of Scrap and Recycled Aggregate
Although the use of scrap and recycled materials is not allowed in India till today due to lack of standards, in developed countries it is very much encouraged nowadays due to the huge dumping problem. The Condominium complex in Humberg was constructed with recycled aggregate 50 years ago and is in good condition.
Benefits of Green Building
In short, in can be concluded that the potential benefits obtained from green buildings can be summarized as follows:
* Enhance and protect ecosystems and biodiversity
* Improve air and water quality
* Reduce solid waste
* Conserve natural resources
* Reduce operating costs
* Enhance asset value and profits
* Improve employee productivity and satisfaction
* Optimize life-cycle economic performance
Health and Community Benefits
* Improve air, thermal, and acoustic environments
* Enhance occupant comfort and health
* Minimize strain on local infrastructure
* Contribute to overall quality of life
* Going Green is ‘future-proofing’ your asset
People across the globe have now come to know that we cannot survive without harmony with nature and that creates the concept of Sustainable Development and Construction, which means that development activities should be so formulated that both nature and human beings can sustain the impact.