LEED and Its Framework
LEED used to be developed by the United States Green Building Council. It is a framework for identifying, implementing, and measuring green building and nearby design, construction, operations, and maintenance. It is a voluntary, market drive, consensus-based tool that serves as a guideline and assessment mechanism. Its ranking systems address commercial, institutional, and residential buildings and nearby developments. It seeks to optimize the use of natural resources, promote regenerative and restorative strategies, maximize the positive and minimize the bad environmental and human health consequences of the construction industry, and furnish high-quality indoor environments for building occupants.
Integrative Process
An integrative process is a complete approach to building systems and equipment. An integrative procedure comprises three phases. The first discovery is also the most important and can be seen as an expansion of what is typically called pre-design. Actions taken during discovery are essential to achieving a project’s environmental goals cost-effectively. The second phase, design and construction, begins with what is conventionally called schematic design. Unlike its conventional counterpart, however, in the integrative process, design will incorporate all of the collective understandings of system interactions that were found during discovery. The third phase is the period of occupancy, operations, and performance feedback. Here, the integrative process measures performance and sets up feedback mechanisms. Feedback is critical to determining success in achieving performance targets, informing building operations, and taking corrective action when targets are missed. A fully integrative process accounts for the interactions among all building and site systems.
Location and Transportation
Location and Transportation (LT) category rewards thoughtful decisions about building location, with credits that encourage compact development, alternative transportation, and connection with amenities, such as restaurants and parks. The SS category now specifically addresses on-site ecosystem services, the LT category considers the existing features of the surrounding community and how this infrastructure affects occupants’ behavior and environmental performance. By recognizing existing patterns of development and land density, project teams can reduce strain on the environment from the material and ecological costs that accompany the creation of new infrastructure. In addition, the compact communities promoted by the LT credits encourage robust and realistic alternatives to private automobile use, such as walking, biking, vehicle shares, and public transit. These incremental steps can have significant benefits.
Sustainable Sites
The Sustainable Sites (SS) category rewards decisions about the environment surrounding the building, with credits that emphasize the vital relationships among buildings, ecosystems, and ecosystem services. It focuses on restoring project site elements, integrating the site with local and regional ecosystems, and preserving the biodiversity that natural systems rely on. Earth’s systems depend on biologically diverse forests, wetlands, coral reefs, and other ecosystems, which are often referred to as “natural capital” because they provide regenerative services.
Water Efficiency
The section is based on an “efficiency first” approach to water conservation in specialized uses, outdoor use, and indoor use. As a result, each prerequisite looks at water efficiency and reductions in potable water use alone. Then, the WE credits additionally recognize the use of non-potable and alternative sources of water. The conservation and creative reuse of water are important because only 3 percent of Earth’s water is fresh water, and of that, slightly over two-thirds is trapped in glaciers. Typically, most of a building’s water cycles through the building and then flows off-site as wastewater.
Energy and Atmosphere
The present worldwide mix of energy resources is weighted heavily toward oil, coal, and natural gas. In addition to emitting greenhouse gases, these resources are nonrenewable: their quantities are limited or they cannot be replaced as fast as they are consumed. Though estimates regarding the remaining quantity of these resources vary, it is clear that the current reliance on nonrenewable energy sources is not sustainable and involves increasingly destructive extraction processes, uncertain supplies, escalating market prices, and national security vulnerability. Accounting for approximately 40 percent of the total energy used today, buildings are significant contributors to these problems. Energy efficiency in a green building starts with a focus on design that reduces overall energy needs, such as building orientation and glazing selection, and the choice of climate-appropriate building materials. Strategies such as passive heating and cooling, natural ventilation, and high-efficiency reduce a building’s energy use.
Materials and Resources
The Materials and Resources (MR) category focuses on minimizing the embodied energy and other impacts associated with the extraction, processing, transport, maintenance, and disposal of building materials. The requirements are designed to support a life-cycle approach that improves performance and promotes resource efficiency. Construction and demolition waste constitutes about 40 percent of the total solid waste stream in the United States, and about 25 percent of the total waste stream in the European Union. As per the United States Environmental Protection Agency (EPA) rankings, source reduction, reuse, recycling, and waste to energy are the four preferred strategies for reducing waste. LEED has consistently rewarded the reuse of materials.
Indoor Environmental Quality
Green buildings with good indoor environmental quality protect the health and comfort of building occupants. High-quality indoor environments also enhance productivity, decrease absenteeism, improve the building’s value, and reduce liability for building designers and owners. The relationship between the indoor environment and the health and comfort of building occupants is complex and still not fully understood. Local customs and expectations, occupants’ activities, and the building’s site, design, and construction are just a few of the variables that make it difficult to quantify and measure the direct effect of a building on its occupants. Therefore, the EQ section balances the need for prescriptive measures with more performance-oriented credit requirements. For example, source control is addressed first, in a prerequisite, and a later credit then specifies an indoor air quality assessment to measure the actual outcome of those strategies.
Innovation
Sustainable design strategies and measures are constantly evolving and improving. New technologies are continually introduced to the marketplace, and up-to-date scientific research influences building design strategies. Occasionally, a strategy results in building performance that greatly exceeds what is required in an existing LEED credit. Other strategies may not be addressed by any LEED prerequisite or credit but warrant consideration for their sustainability benefits.
Regional Priority
Due to some environmental issues being particular to a locale, volunteers from USGBC chapters and the LEED International Roundtable have identified distinct environmental priorities within their areas and the credits that address those issues. USGBC established a process that identified six RP credits for every location and every rating system within chapter or country boundaries. Participants were asked to determine which environmental issues were most salient in their chapter area or country. The issues could be naturally occurring (for example, water shortages) or man-made (for example, polluted watersheds) and could reflect environmental concerns (for example, water shortages) or environmental assets (for example, abundant sunlight).
Reference
LEED (Leadership Energy and Environmental Design), (2013). Reference guide for building Design and construction. U.S. Green Building Council.
