This essay has been submitted by a student. This is not an example of the work written by our professional essay writers.
Sustainability definition is different from person to person and from agency to agency depending on their background. The World Congress of Architects (WCA) said, in Chicago, in 1993, "Sustainability means meeting the needs of the current generation without compromising the ability of future generations to meet their own needs," (CAA, 2012). Another definition by Environmental Protection Agency (EPA 2012) is "Sustainability is based on a simple principle: Everything that we need for our survival and well-being depends, either directly or indirectly, on our natural environment.Â Sustainability creates and maintains the conditions under which humans and nature can exist in productive harmony, that permit fulfilling the social, economic and other requirements of present and future generations." Figure 1 shows the major elements of sustainability that U.S. Green Building Council is focused on, and they are economic prosperity, environmental stewardship, and social responsibility, known as "the triple bottom line" or "the three-legged stood."
U.S. Green Building Council (USGBC):
U.S. Green Building Council (USGBC) has been established in 1993, and has more than 18,000 member companies and organizations, members who have different background in the buildings industry. USGBC is a nonprofit organization, and their aim is to upgrade the buildings and communities by considering the triple bottom line in building's life cycle, which improves the final occupants' health and their quality of life (USGBC 2009).
USGBC's programs have three unique features. Frist, committee-based, integrating the volunteers' ideas and plans with the expert consultants that creates solutions improve the building's life cycle including design, construction, and operation phases. Second, member-driven, focusing on the issues that identified by its members and consider it a priority, so they set polices and revises strategies based on the members need. Third, consensus-focused, applying policies those are enhancing the green building by increasing the economic value and environmental health with decent costs (USGBC 2009).
Leadership in Energy and Environmental Design (LEED), which is the most recognized green building initiative, was created by USGBC. LEED is a green building certification system that evaluates the environmental performance and impact of a building over its lifecycle. The LEED certification program was first implemented in 1998 and, since then, has grown to encompass more than 25,000 commercial projects and 1.6 billion square feet of developed space (USGBC 2012). There are nine different versions of LEED's rating systems, which are LEED - Homes, LEED - Neighborhood Development, LEED - Commercial Interiors, LEED - Core and Shell, LEED - New Construction, LEED - Schools, LEED - Retail, LEED - Healthcare, and LEED - Existing Buildings (Operation and Maintenance). Among all these rating systems, LEED - New Construction is the most commonly used, which will be focus on at this paper. LEED-NC has almost fifty-five credits with 110 possible points to achieve, and have four levels of certification (certified 40-49 points, silver 50-59 points, gold 60-79 points, and platinum 80 points and above). Therefore, the more number of points is achieved, the higher certification level is achieved. This rating system has five main categories (sustainable sites, water efficiency, energy and atmosphere, material and resources, and indoor environmental quality), and two supported categories (innovation in design, and regional priority), (USGBC 2012).
This category has one prerequisite and eight credits with 26 possible points to obtain. The prerequisite of this category aims on reducing the pollution on the construction sites by controlling the soil erosion, waterway sedimentation, and airborne dust generation. However, the credits of this category are focusing on (1) site selection by avoiding development on inappropriate sites and reducing the environmental impact, (2) development density and community connectivity by channel development to urban areas and protecting the greenfield, habitat, and natural resources, (3) rehabilitating the brownfield (damaged) sites and conserving the existing natural areas, (4) reducing pollution and land development impact from automobile use by providing an alternative transportation such as public transportation access, bicycle storage and changing rooms, using low emitting and fuel efficient vehicles, and parking capacity, (5) maximizing the open space by providing a high ratio of open space to development footprint, (6) limiting the disruption of natural hydrology by managing the stormwater runoff, (7) reducing the heat island effect by implementing, for example, pervious pavements and/or green roofs, and (8) reducing the light pollution by minimizing light trespass from building and site, and improving the night time visibility through glare reduction, especially at the nocturnal environments, (USGBC 2009).
This category has one prerequisite and three credits with 10 possible points to obtain. The prerequisite of this category is focusing on reducing wastewater and the demand of municipal water supply that increase the water efficiency. However, the credits of this category are focusing on (1) limiting or eliminating the use of potable water for landscape irrigation, and (2) increasing water efficiency within buildings, (USGBC 2009).
Energy and Atmosphere:
This category has three prerequisites and six credits with 35 possible points to obtain. The prerequisites of this category are focusing on reducing energy use by establishing minimum levels of energy efficiency, reducing the ozone depletion, lowering operation costs, and improving occupants' productivity. However, the credits of this category are focusing on (1) optimize energy performance by increasing the energy performance levels beyond the prerequisite, (2) encouraging to apply on-site renewable energy, like solar system panels that reduce the fossil fuel environmental and economic impacts, (3) beginning the commissioning process early in the design phase, (4) applying measurement and verification which is accounting of building energy consumption over time, and (5) encouraging the owner to use the grid-source renewable energy, for example, the owner could contribute to provide power in the state by signing a 2-year contract for a minimum of 35% of the annual electrical power consumption from a Green-e-certified provider, (USGBC 2009).
Material and Resources:
This category has one prerequisite and seven credits with 14 possible points to obtain. The prerequisite of this category is to storage and collection of recyclables by facilitating reduction of waste generated by building occupants. However, the credits of this category are focusing on (1) maintaining and extending the life cycle of the existing building's walls, floors, roofs, and interior non-structural elements by reuse it, (2) management the construction waste by diverting the debris (like concrete, wood, and steel) on the construction sites from landfill sites to the recycle bins, (3) reusing the building materials which reducing impacts resulting from extraction and processing of virgin materials, for example, using a door from an existing building as a finishing floor on a new building, (4) increasing the demand for building products that use recycled content materials. For example, recycle the rest of the carpet or broken ceramic tiles during the construction or after construction (post-consumer), or recycle the damaged carpet or broken ceramic tiles during manufacturing (pre-consumer), (5) increasing the demand for regionally (within 500 mile) extracted and manufactured building materials, (6) using the rapidly renewable materials such as bamboo, and reduce using the finite raw materials like oak wood, and (7) using certified wood that have forest stewardship council's certification (FSC-certified) to encourage the forest management, (USGBC 2009).
Indoor Environmental Quality:
This category has two prerequisites and eight credits with 15 possible points to obtain. The prerequisites of this category are (1) establishing minimum indoor air quality performance to ensure good air quality for the comfort and well being of the occupants, and (2) minimizing or preventing exposure of occupants, surfaces, and ventilation systems to tobacco smoke. However, the credits of this category are focusing on (1) monitoring for occupant comfort and wellbeing by installing outdoor air ventilation system, (2) applying the construction indoor air quality management plan during the construction and before occupancy to reduce indoor air quality problems resulting from construction activity, and to promote comfort and well being of construction workers and occupants, (3) using low-emitting materials (like adhesives and sealants, paints and coatings, and flooring systems) that have limited volatile organic compound (VOC), and materials (like composite wood and agrifiber products) that have contain no added urea-formaldehyde resins, to reduce the quantity of indoor air contaminates that are harmful to occupants, (4) minimizing exposure of occupants to hazardous particulates or chemical pollutants by controlling them, (5) promoting the occupants productivity and comfort by providing them lighting and thermal comfort systems that controlled individually or controlled by groups in multi-occupant spaces, (6) providing a comfortable thermal environmental, which promotes occupant productivity and wellbeing, and verify it by applying an overtime assessment, and (7) connecting the indoor and the outdoor spaces by large windows that introducing daylight and views, (USGBC 2009).
Innovation in Design:
This category has two credits with 6 possible points to obtain. The credits of this category includes (1) innovation in design by creating new strategy that fulfills with the previous five categories main intents and not addressed in the LEED reference guide, (2) exemplary performance by achieving the next threshold of the previous five categories credits. For example, if a company select a site has access to two bus stops with Â¼ mile, they will achieve points under alternative transportation credit. However, if they select a site has four bus stops with Â¼ mile, they will achieve an additional point under exemplary performance credit, and (3) including a LEED Accredited Professional to the project team, which adds one point to the project, (USGBC 2009).
This category has one credit with 4 possible points to obtain. LEED credits which are designated by the USGBC as more challenging to achieve within certain zip codes. Therefore, an additional point could be achieved if one of the five categories credits achieved in a particular area and considered as regional priority in the same area; same scenario could apply up to four points for four different regional priority credits, (USGBC 2009).
LEED Certification process and its fees:
Once the rating system has been determined and the appropriate registration fee has been paid ($900 for USGBC members, and $1,200 for non-members), the project will be immediately accessible in LEED Online, which is the primary resource for managing the LEED documentation process. At the beginning, the project team should collect information and perform calculations for all prerequisites and the credits that have chosen to pursue. The project team could request the Credit Interpretation Ruling (CIRs) if they need technical clarification on some credits, which will cost them $220/credit. After preparing all prerequisites and credits documentation, the LEED Project Administrator should fill out the credits forms and upload these materials to LEED Online and start the application review process. Fees are required to complete the review process. Therefore, as standard review (design and construction review), if the projects less than 50,000 SF, the USGBC member will pay $2,250 and non-member will pay $2,750 as flat rate. But if the project size between 50,000SF and 500,000SF, the USGBC member will pay $0.45/SF and non-member will pay $0.55/SF. However, if the project is larger than 500,000SF, the USGBC member will pay $22,500 and non-member will pay $27,500 as flat rate. And to expedite the review process, $10,000 will be pied as a surcharge. (GBCI, 2012)
Once the project teams submitted the completed documentation requirements for all prerequisites and at least the minimum number of credits required to achieve certification, as well as USGBC community members completed the final application review, the project team can either accept the final decision and receive the appropriate certificate, or appeal it to get higher certificate level. Therefore, if the project team decided to appeal the community decision, they have to pay $800/credit for complex credits and $500/credit for all other credits. (GBCI, 2012)
Green buildings benefits:
According to USGBC, buildings industry, in the United States, has a huge environmental impact among all other industries. It consumes 12% of water use, 30% of greenhouse gas emissions, 65% of waste output, and 70% of electricity consumption. However, Green buildings can save at least 30% of energy, 35% of carbon, 30% - 50% of water use, and 50% - 90% of waste costs, (USGBC 2012). The adoption of the LEED rating system has greatly increased in recent years. This trend is due to the perceived benefits attributed to green buildings, both in terms of positive environmental impact and reduction of utility costs as well as higher occupancy and rental rates (Eicholtz et al. 2008; Fuerst et al. 2008; Miller et al. 2008). More examples of benefits associated with green buildings include the conservation of natural resources, reduced waste sent to landfills, improvements in air and water quality, reduced operating costs and increased asset value, reduced harmful greenhouse gas emissions, and enhanced occupant comfort and health (GBCI 2012). "On average, Americans spend about 90 percent or more of their time indoors" (EPA 2012). According to Miller et al. (2009), Healthier buildings, which have good ventilation, natural light, absence of voltaic organic compounds (VOC), and localized controls, reduce sick time and increase productivity.
Green buildings' impact on workers safety:
The construction industry's current perspective of sustainability is mainly focused on the principles of resource efficiency and the health and productivity of the final occupants of the building. However, it has been argued that sustainability should be considered across a building's entire lifecycle, and that it should include the health and wellbeing of construction workers (Rajendran et al. 2009).
There have been a substantial number of studies that have evaluated the impact of LEED certification on worker safety and health. Rajendran et al. (2009) conducted a study on 86 projects to test for a difference on safety performance between green and non-green projects. They found moderate statistical evidence that LEED certified projects incur higher OSHA recordable injury rates (RIR) than conventional construction projects. Following this study, Fortunato et al. (2012) conducted six detailed case studies to identify how the common design elements and construction practices implemented to achieve LEED certification affect construction worker safety and health. The case studies revealed that, out of the fifty-five applicable credits, twelve increase safety risks when compared to conventional projects because workers are exposed to unfamiliar situations and additional work at height, near electrical systems, in proximity to unstable soils, and around heavy equipment. Hazards are summarized for specific credits later in the manuscript.
Dewlaney et al. (2012) built upon this work by quantifying the increase or decrease in base-level safety risk for the credits highlighted by Fortunato et al. (2012). Through a total of 37 interviews with experienced designers and contractors, they concluded that the most significant negative impacts to construction safety are the heat island effect-roof (19% increase in eye strain when installing reflective roof membranes), on-site renewable energy (24% increase in falls to lower level during roof work), and construction waste management (36% increase in lacerations, strains and sprains).
In recent research Dewlaney and Hallowell (2012) identified design and management techniques to mitigate the risks associated with the means and methods used to achieve LEED certification. Through interviews with experienced design engineers and construction professionals, this study found specific strategies to mitigate each of the hazards that were identified by Fortunato et al. (2012).