This article was researched and written by students at Allegheny College participating in the Encyclopedia of Earth's (EoE) Student Science Communication Project. The project encourages students in undergraduate and graduate programs to write about timely scientific issues under close faculty guidance. All articles have been reviewed by internal EoE editors, and by independent experts on each topic.
Sustainable urban development may be defined as development which achieves lasting health in the physical,social and cultural environment of an urban community.
Creating sustainable urban development is important in the United States because 80% of the population lives in urban areas. Most of these communities, in the past, have not been built to last or with the environment in mind. Examples are developments which have led to urban sprawl.
The building sector uses about 40% of the nation’s total consumption of primary energy, uses about 70% of the nation’s total electricity, and emits about 40% of the nation’s total carbon dioxide annually. Reducing these is a key aspect of sustainable urban development. Also, sustainable building practices, transportation, land use and water use must be taken into account.
In order to reduce the amount of raw materials consumed and the amount of toxins emitted, a focus has been placed on retrofitting existing buildings. Urban planners also are responding to the need to focus on constructing economically feasible, socially desirable, and environmentally friendly buildings. With such programs as Leadership in Energy and Environmental Design (LEED) in place, there are many more opportunities for developers and contractors to produce more sustainable products.
In urban areas, building new energy efficient buildings may not always be the answer to being environmentally conscious. Urban retrofitting is the process of redesigning an existing infrastructure into one which is more sustainable. In years past, contractors have been deterred from urban retrofitting because there was a lack of evidence to show they would not lose profits in the process. However, a study at the University of Wisconsin in Madison has found that retrofitting buildings does not pose a high investment risk and has a high annual return of 22%.
With carbon dioxide emissions at about 40%, the building sector is the largest emitter of carbon dioxide emissions followed by the residential, commercial and industrial sectors at 21%, 17%, and 5% respectively. A major benefit of retrofitting buildings instead of constructing brand new ones is that the greenhouse gas emissions normally produced during construction are greatly reduced. Other major benefits are: improvements to the environment, increased health and productivity for workers and residents in the area, property owners and tenants save money, the value of the restored and renovated property goes up and the jobs created cannot be outsourced.
When state or local governments take on the retrofitting of public buildings they and their citizens benefit by reducing their energy consumption. They also provide an example of an environmentally sustainable project. Starting to retrofit buildings at a small level through local and state governments could be the catalyst the United States needs to take greater steps toward relying more on renewable technologies.
Although only 2% of construction projects involve building new structures, it is still an important source of energy consumption and greenhouse gas emission that needs to be addressed now to set higher building standards for the future. One way that building standards are being addressed is through buildings becoming LEED certified. The LEED program was created by the U.S. Green Building Council (USGBC) to directly address the need for green buildings in the 21st Century.
LEED identifies a framework which can be used throughout the building process. The standards for the LEED program aim to save energy, be more water efficient, emit a significantly decreased amount of carbon dioxide, create a more cohesive feel between the inside of the building and the natural environment, as well as acknowledging the resources put into the building and being able to appreciate them. Not only are LEED certified facilities meant to be more technologically efficient, they help make people more environmentally aware.
There are different levels of LEED certification. This allows sustainable development to reach those who are already environmentally aware and looking to go to the next level (for example, Platinum certification) and those who are taking the first steps into sustainable development (for example, Bronze certification).
In the past decade LEED has become an increasingly popular program adopted by commercial companies, schools, retail premises, healthcare facilities, homes and communities as a whole. For example, Google, Allegheny College and the University Medical Center of Princeton at Plainsboro, New Jersey have all met the LEED criteria.
LEED is not the only building assessment program in the United States. Green Globes is a building guidance and assessment program which began from the Building Research Establishment’s Environmental Assessment Method (BREEAM) in Canada in 1996. It focuses on assessing how environmentally friendly buildings are, best practices for construction and operations, and software tools which allow complete assessments online.
Preserving land is one way governments, developers, and consumers can help achieve sustainable urban development. Taking a natural environment and creating an industrialized environment usually occurs through modifying fields, pastures, and settlements. The use of these lands results in urban sprawl. Urban sprawl can be described as the spreading of a city to the suburbs and beyond. Urban sprawl causes certain disadvantages such as long transport distances to work, high single-user vehicle dependence, long distances from health and cultural facilities and higher per-person infrastructure costs. Because of these disadvantages urban renewal has begun to take place. This has led to an influx of people into urban centres so land use in cities and towns is being re-evaluated.
Retrofitting buildings is one way to preserve land in urban areas. By using already existing buildings developers do not need to break new ground. In urban areas, establishing a protected plot of land is difficult due to the small amount of available open space in these kinds of environments. Therefore, using the already existing, urbanized land areas helps keep land use to a minimum in urban settings.
Some efforts are being made to improve existing public transit and promote pedestrian activities. For example, New York City has invested time and money into making more bike lanes on city streets. However, changing the transportation habits of a society is difficult. Some other problems include increasing congestion, lack of room to build new roads, and over-consumption of petroleum.
There are many transportation alternatives now which are more sustainable and create a better environment in communities. These alternatives include ridesharing, using city and intercity buses and trains, biking, and walking. Washington D.C. is an example of all alternatives being utilized. Because of the number of people who work directly in the city, making transportation fast and easy makes the lives of the commuters easier. In the D.C. area there is the Metro system which consists of buses and trains. Many of the buses are being converted to run on compressed natural gas, decreasing the carbon footprint they create. The rideshare program in place in D.C. allows commuters from the bordering towns and cities to leave their cars in parking lots called ‘Park and Ride’. These people can then take buses or trains into the downtown, where there is a lot of congestion. Biking and walking has also become a very popular form of transportation in the D.C. area. Many of the government buildings (for example, the Ronald Reagan Building and International Trade Center) are now equipped with bicycle racks.
- United Nations. (1987) “Report of the World Commission on Environment and Development.” General Assembly Resolution 42/187. Retrieved from: http://www.un.org/documents/ga/res/42/ares42-187.htm
- United Nations. (1983) “Process of Preparation of the Environmental Prospective to the Year 2000 and Beyond.” General Assembly Resolution 38/161. Retrieved from: http://www.un.org/documents/ga/res/38/a38r161.htm
- World Commission on Environment and Development (WCED). Our common future. Oxford: Oxford University Press, 1987 p. 43.
- Holness, G.V.R. (2009) “Sustaining Our Future By Rebuilding Our Past.” ASHRAE Journal
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- The Apollo Alliance and ICLEI Local Governments for Sustainability. (2005). “Buildings, Operations and Purchasing.” High Performance Cities: A guide to energy-saving policies for urban areas. Retrieved from: http://www.cows.org/about_publications_detail.asp?id=323
- Wheeler, S. (1998) Planning Sustainable and Livable Cities Routledge: New York
- United Nations Population Fund (2007) State of World Population 2007: Unleashing the Potential of Urban Growth. Retrieved from: http://www.unfpa.org/swp/2007/presskit/pdf/sowp2007_eng.pdf
- Green Globes (2010) "Green Globes:The Green Building Initiative" Retrieved from: http://www.thegbi.org/green-globes-tools/