Effect Of Green Construction In The Urban Environment
Er. Sumeet Agarwal, HOD Recovery & Consulting Services,
Sustainable Environment and Ecological Development Society,
Increasing urbanization has resulted in a spurt in construction activities which, in addition to providing jobs and spaces for living and working, have also created many problems like generation of waste during construction and demolition, spike in demand for water and energy, emissions from materials like paints. Construction industry is estimated to be responsible for 18% of carbon emissions. Cities cover 2% of the world’s land area but account for 70% of greenhouse gas emission, 30% of which are caused by buildings. In view of the issues it is imperative to re-examine the construction practices and try at greening the construction practices to reduce adverse impacts on environment and to reduce living and maintenance costs. It has been reported that compared to traditional construction, green buildings have reduced CO2 emissions by as much as 34%. Green buildings are designed to use less water and energy and improve indoor environment including air quality. Different rating systems are used for green construction, the commonest being the LEED (Leadership in environment and energy design) system. India also has a rating
system for green buildings known as Green Rating for Integrated Habitat Assessment (GRIHA). The rating system consists of 31 criteria categorized under various sections such as Site Planning, Construction Management, Occupant Comfort and Wellbeing, Sustainable Building Materials, Performance Monitoring and Validation, and Innovation. All buildings, which are in the design stage and have built up area more than 2,500 m2, are eligible for certification under GRIHA. Building types include, but are not limited to offices, retail spaces, institutional buildings, hotels, hospital buildings, healthcare facilities, residences, and multi-family high-rise buildings. As seen from the above initiatives, the interest and awareness in Green building systems has been growing in various countries as they face greater environmental issues and find it advantageous to adopt green building systems to address these. However, considering the scale and severity of issues in a rapidly urbanizing world, a more widespread adoption of green building practices at city level would help to develop a sustainable built environment through inherent positive impacts of green construction practices. Such buildings would form an integral part of the smart cities, which are coming up in various countries across the world. Considering the need for green development at a larger scale, beyond the building envelope, a concept of “Green Districts” is emerging, which envisages a densely populated and geographically cohesive area located within and city that employs technology and design elements to reduce resource use and pollution. In general, green districts deploy design principles that lead to dense, transit oriented, mixed use developments and renewable energy sources. The US Green Building Council, which developed the LEED rating system, has also introduced a system known as LEED for Neighbourhood Development (LEED- ND). According to the council the system aims to integrate ideas of New Urbanism, Smart Growth and Green Buildings. The concept of green districts is being widely supported by a number of organizations worldwide and is already being used to revitalize a number of North American cities.
Green districts use various technologies and design elements such as:
- Dedicated bus/ car pool lanes
- Pedestrian friendly streets and streetscapes
- Bike infrastructure
- Trees/ urban forestry
- Permeable pavements and green alleys
- Green roofs
- Energy- efficient street lighting
- Pneumatic waste transport system
- Combined heat and power systems
- Grey water recycling systems
- Anaerobic digestion
- Rain water harvesting
- Renewable energy systems
- Smart grids
- Waste to energy systems
Many above mentioned elements and technologies are also part of India’s smart city concept. It has been seen that though the initial cost of development using the above-mentioned technologies and elements is high, these are recovered over a period, making use of these technologies and elements not only viable, but also profitable. However, advantage of green district development should not be seen only in terms of economic costs since they provide significant environmental and health benefits also. They are known to reduce wastes being moved to landfills by as much as 25%, reduce energy consumption by 20-25% and use of freshwater and waste water generation by as much as 60-65%. Such benefits would address many urban issues that Indian cities are grappling with in modern times. Solutions to address issues like scarcity of landfill sites can be implemented on priority to conserve valuable urban land and to reduce the adverse impacts on environment. Green district developments could also contribute to reduction in air pollution, which have been plaguing cities like Delhi, through development of environment friendly and pedestrian friendly transport modes. Such developments can form part of the system of Local Area Plans introduced into planning practices of many cities since many elements, technologies and actions would be required at the local level to ensure development of green districts. Development of such districts can also be integrated into redevelopment or revitalization plans of parts of cities, such as old city areas. However, integration of such concepts would need a shift in emphasis from financial viability of development to environmental and health impacts of planned development since, though the cost of adverse impacts on environment and health are not immediately apparent, the long-term cost in terms of increase in impacts of natural hazards due to environmental degradation and stress on health infrastructure would be very high. In recent years the city of Vancouver, Canada has figured prominently in green building and green city development. It has developed a Greenest City Action Plan, which would help it develop as a major Green city by 2050. The citizens and the city government are working jointly towards green transformation of the city. As a part of the initiative, the city plans to reduce greenhouse gas emissions of new homes by 33% by 2020 with the aim of making all new buildings carbon neutral by 2030. Greenhouse gas emissions from existing buildings will also be reduced by 20% over 2007 levels. The vision of the green action plan is to develop opportunities while building:
- Vibrant and inclusive neighbourhoods
- Internationally recognized city that meets the needs of generations to come
The city action plan is divided into 10 goal areas addressing three overarching areas of focus, which are:
- Zero carbon
- Zero waste
- Healthy ecosystems
Each goal has at least one measurable target for 2020. Each of the goals and their targets are as under.
Climate and Renewables
The target is to reduce community based greenhouse gases by 33% from 2007 levels by 2020. Some of the initiatives that are helping to meet the goal are:
- Neighbourhood energy strategy which aims to i) Cut carbon emissions, ii) Reduce our dependence on fossil fuels, iii) Keep energy affordable in the long term, and iv) Achieve 100% of our energy needs from renewable sources before 2050. Neighbourhood renewable energy systems supply central heating, hot water and cooling using renewable energy systems like heat generated from sewage waste. Such systems, besides reducing the use of fossil fuels also obviate the need for individual boilers in buildings.
- Zero emissions building plan, which will eliminate emissions from new buildings by 2030. The plan mandates that all new buildings may be constructed to produce little or no Green House Gas (GHG) emissions by: i) Being built to a zero-emission standard like the Passive House standard (which essentially reduces energy demand), ii) Connecting to a neighbourhood energy utility (increasing renewable energy supply), iii) Building all future city facilities to a zero-emission standard, and iv) Developing tools to catalyse private sector leaders to do the same.
The city recognizes the fact that electricity and natural gas being utilised by the buildings are responsible for GHG emissions. Hence, an attempt is being made to improve the performance of buildings through certain initiatives, some of which are:
- Preparation of zero emissions building plan to eliminate emissions from new buildings by 2030 through energy efficiency and renewable energy.
- Neighbourhood energy strategy that seeks to develop additional energy systems throughout the city.
- Building retrofit strategy.
The city aims to provide fast, reliable, frequent and accessible transit. It aims to improve quality of life by making Vancouver a city where moving on foot or by bike is safe, convenient and enjoyable. The city’s targets for green transportation are:
- Make the majority (more than 50%) of trips by foot, bicycle and public transit.
- Reduce average distance driven per resident by 20% from 2007 levels.
The initiatives the city is introducing include: i) Public bike share program, ii) Implementing different projects to make streets safer for bikes, resulting in an increase in ridership, and iii) Repurposing an old rail corridor into a greenway.
The city aims to reduce waste going to landfills or incinerator by 50% from 2008 levels.The initiatives that have helped the city achieve its goals are:
Er. Sumeet Agarwal,
HOD Recovery & Consulting Services, Sustainable
Environment and Ecological Development Society,
- Diversion of construction waste from landfills: 75% of the solid waste generated from demolition of pre-1940 homes in Vancouver must be reused or recycled.
- Diversion of food waste from landfill: Many businesses generating food waste have set up an organic recycling program and food and yard waste collected annually from single family homes has increased by 75%.
- Diversion of electronics from landfills: Many electronics recycling drop-off events were organized in the city and in 2015 about 11,000 electronics and small appliances were diverted from landfills and recycled through drop-off events.
Recognizing the possibility of water stresses due to population growth and climate change, the city has taken several steps to reduce water use. It aims to reduce per capita water consumption by 33% over 2006 levels. The initiatives that are being implemented to help meet the target are:
- Integrated water management plan: In April 2016 the city adopted a target to capture and treat 90% of the city’s average annual rainfall through green infrastructure.
- Reduced laundry water use: Gathering place community centres have been providing free laundry and shower facilities to some communities since 1995. Volunteers worked with laundry users to ensure that the washing machines were running with full loads, resulting in substantial savings of water and energy.
The city is working with businesses, residents and other levels of government to ensure clean air as it is anticipated that air pollution levels would increase with city growth. The city’s target for clean air is to meet or beat the most stringent air quality guidelines from Metro Vancouver, British Columbia, Canada and the World Health Organization. Some initiatives that are helping to meet the goal are:
- Joining the International zero vehicle emissions alliance: The International Zero-Emission Vehicle Alliance (ZEV Alliance) is a collaboration of national and sub-national governments working together to accelerate adoption of Zero Emission Vehicles. The participants set ambitious, achievable targets for ZEV deployment, take actions to achieve those targets as appropriate in each jurisdiction, act together to achieve individual and collective targets, and encourage and support other jurisdictions in setting and achieving ambitious Zero Emission Vehicles targets.
- The city completed installation of electric vehicle charging infrastructure. 111 charging stations were installed across the city from 2011. These stations are helping to address public concerns about lack of infrastructure for electric vehicles and help to incentivize adoption of such vehicles.
- Adoption of neighbourhood energy strategy, which envisages development of neighbourhood renewable energy systems throughout Vancouver city, which is key to meeting greenest city 2020 action plan.
The goal of sustainable development can be met only through citywide green development. Green constructions would be a part of the green development plan on a citywide scale to have the desired impact. Cities need to prepare a green development Master plan and set goals for green development to ensure time bound implementation of development processes. Cities like Vancouver can set examples for development. The codes also need to make green development mandatory.
1. https://www.nationalgeographic.com/environment/urban-expeditions/greenbuildings/ benefits-of-green-buildings-human-health-economics-environment/
2. https://www.nationalgeographic.com/environment/urban-expeditions/greenbuildings/ benefits-of-green-buildings-human-health-economics-environment
4. https://www.mckinsey.com/business-functions/sustainability-and-resourceproductivity/ our-insights/building-the-cities-of-the-future-with-greendistricts
5. http://vancouver.ca/home-property-development/green-building-andrenovating. aspx
7. http://climateinitiativesplatform.org/index.php/International_Zero-Emission_ Vehicle_Alliance_(ZEV_Alliance)
9. https://www.nationalgeographic.com/environment/urban-expeditions/ green-buildings/benefits-of-green-buildings-human-health-economicsenvironment/
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