Green building also known as green construction or sustainable building
The energy, water and materials demands for buildings have been growing enormously over the years and the need has arisen to minimize natural resource consumption in building and associated impact on the environment. Buildings are responsible for 40% of global emissions and 60% of the wastes globally.
Green Buildings are environmentally sustainable homes that give prominence to the efficient use of energy, water, and building materials. It is primarily done to create an ecofriendly and pollution free environment for families and communities residing in them.
Green Buildings (also known as green construction or sustainable buildings) offer some of the most effective means to achieving a range of global goals, such as addressing climate change, creating sustainable and thriving communities, and driving economic growth. The goal is to convert buildings to energy neutral structures.
"A green building is one which uses less water, improves energy efficiency, conserves natural resources, generates less waste and provides healthier spaces for occupants, as compared to a conventional building”.
Green buildings can play a catalytic role in addressing environmental issues and concerns. A green building incorporates the following features:
Better living conditions
Eco-friendly sustainable materials
Less transport use
Green buildings offer a number of economic benefits as well. These include cost savings on utility bills for tenants or owners through energy and water efficiency; lower construction costs and higher property value for building developers; increased occupancy rates, lower operating costs for building owners; job creation, health and well-being of occupants.
A sample list of green building features are as mentioned below:-
Building Design- Orient building to allow optimum sunlight and ventilation
Envelope- High performance walls, roofs
Glass- High performance glass-Low-E Glass, double glazed units, triple- glazed units.
Appliances- BEE star rated equipment and appliances
Lighting Systems- Energy efficient lamps and luminaries
Renewable energy sources- Solar photovoltaic, solar water heaters, biogas etc.
Energy Monitoring- Energy meters & sub meters to measure, monitor & sustain building performance.
Water Fixtures- Use ultra low & low flow & flush water fixtures
Water Management- Provide rain water harvesting / storage structures, Treat 100% of waste water onsite, Use water meters to monitor the consumption of treated grey water, irrigation water, rainwater reuse, domestic hot water etc.
Sourcing of Building Materials- Use eco-friendly building materials and try to source materials that are locally manufactured (within 400 km) from project site
Certified Wood- Use wood certified by local forestry or rapidly renewable materials (plantations which can completely replenish within 10 years) for all wooden products & furniture.
Sustainable Site measures- Retain fertile top soil excavated during construction for landscaping during post-occupancy, Maximise the vegetated open space in the building.
Transportation- Use alternate fuel vehicles such as electric cars for local conveyance and encourage car/van pooling and public transport.
Landscaping- Reuse treated waste water for landscaping, Use drought tolerant and native species for landscape to reduce irrigation requirement (Xeriscaping)
Irrigation efficiency- Use drip and sprinkler irrigation systems for enhanced water efficiency
Interior Finishing Materials- Use NO or low VOC (Volatile Organic Compound) materials Ventilation & day lighting - Design openings to enhance cross ventilation, Ensure maximum daylight into all occupied spaces
Views for occupants- Design interior layouts which would provide a better connectivity to the occupants with the external world
The various green building rating systems are BEE Star Ratings for buildings, GRIHA, IGBC and USGBC based-LEED certifications. All of these use Energy Conservation Building Code (ECBC) 2017 as the baseline requirement to evaluate energy consumption of building.
IGBC Green Building Rating Systems
IGBC Green Building Rating Systems have been developed by the Indian Green Building Council (IGBC) to suit the national context and priorities. The Rating System incorporates National Standards and Codes namely National Building Code (NBC), Energy Conservation Building Code (ECBC), Ministry of Environment & Forests (MoEF) and Central Pollution Control Board (CPCB) guidelines.
National priorities addressed in this rating system include water conservation, waste management, energy efficiency, reduced use of fossil fuels and lesser dependence on usage of virgin materials. Different rating systems are developed for different building types: commercial, residential, cities, townships, schools, healthcare, data centres and several others.
Green Rating for Integrated Habitat Assessment (GRIHA)
Green Rating for Integrated Habitat Assessment (GRIHA) is the rating system jointly developed by TERI and the Ministry of New and Renewable Energy, Government of India. GRIHA is aimed at using best of traditional architecture and modern technology to build new buildings. The latest version of GRIHA is called GRIHA V – 2015. Buildings would be rated on a 1-5 star scale, with 5 star labeled buildings being the most efficient. GRIHA rating system consists of 31 criteria and points are assigned to different criteria which reflect current resource priorities of India.
LEED, which is Leadership in Energy and Environmental Design, is a third party certification for design, construction and operation of a given building. US Green Building Council (USGBC) has completed a comprehensive update of LEED which is called LEED v4. Seven impact categories considered under LEED are as follows:
Reverse contributing to global climatic change
Enhance individual human health and well-being
Protect and restore water resources
Protect, enhance and restore biodiversity and ecosystem resources
Promote sustainable and regenerative resource cycles
Built a greener economy
Enhance social equality, environmental justice, and community quality of life.
Other International Rating Schemes for Buildings
Other international rating schemes include US Environmental Protection Agency (USEPA) energy star and National Australian Built Environment Rating System (NABERS). USEPA energy star for buildings is more popular internationally and accounts for data centers and labs. NABERS is specific to Australia and is designed taking into account density of workspace. The number of employees working in the main shift, number of workstations, efficiencies of the UPS and allied systems to ensure uninterrupted power supply to IT equipment and the server rooms influence the energy performance and need.
Source:- Refresher Course for Certified Energy Managers and Auditors by BEE 2018