- Leadership in Energy and Environmental Design
The Leadership in Energy and Environmental Design (LEED) Green Building Rating System, developed by the
U.S. Green Building Council (USGBC), provides a suite of standards for environmentally sustainable construction. Since its inception in 1998, LEED has grown to encompass more than 14,000 projects in 50 US States and 30 countries covering 1.062 billion square feet (99 km²) of development area. [ [https://www.usgbc.org/ShowFile.aspx?DocumentID=2349 July 2007 USGBC figures] ] The hallmark of LEED is that it is an open and transparent process where the technical criteria proposed by the LEED committees are publicly reviewed for approval by the more than 10,000 membership organizations that currently constitute the USGBC.Individuals recognized for their knowledge of the LEED rating system are permitted to use the LEED Accredited Professional (AP) acronym after their name, indicating they have passed the accreditation exam given by the USGBC.
History
LEED began its development in 1994 spearheaded by
Natural Resources Defense Council (NRDC) senior scientistRobert K. Watson who, as founding chairman of the LEED Steering Committee until 2006, led a broad-based consensus process which included non-profit organizations, government agencies,architect s,engineer s,developer s,builder s, product manufacturers and other industry leaders. Early LEED committee members also included USGBC co-founder Mike Italiano, architects Bill Reed and Sandy Mendler, builder Gerard Heiber and engineer Richard Bourne. As interest in LEED grew, in 1996, engineers Tom Paladino and Lynn Barker co-chaired the newly formed LEED technical committee.From 1994 to 2006, LEED grew from one standard for new construction to a comprehensive system of six interrelated standards covering all aspects of the development and construction process. LEED also has grown from six volunteers on one committee to more than 200 volunteers on nearly 20 committees and nearly 150 professional staff.
LEED was created to accomplish the following:
*Define "green building " by establishing a common standard of measurement
*Promote integrated, whole-building design practices
*Recognize environmental leadership in the building industry
*Stimulate green competition
*Raise consumer awareness of green building benefits
*Transform the building marketGreen Building Council members, representing every sector of the building industry, developed and continue to refine LEED. The rating system addresses six major areas:
*Sustainable sites
*Water efficiency
*Energy and atmosphere
*Materials and resources
*Indoor environmental quality
*Innovation and design processBenefits and Disadvantages
LEED certified buildings use key resources more efficiently when compared to conventional buildings which are simply built to code. LEED certified buildings are healthier work and living environments, which contributes to higher productivity and improved employee health and comfort. The USGBC has also compiled a long list of benefits of implementing a LEED strategy which ranges from improving air and water quality to reducing solid waste. The fundamental reduction in environmental impacts in addition to all of the economic and occupant benefits goes a long way for making a case for green building. It is also important to note that these benefits are reaped by anyone who comes into contact with the project which includes owners, occupants and society as a whole.
These benefits do not come without a cost however. Green buildings cost more both to design and to construct when compared to conventional buildings. The cost of designing a LEED certified building is higher for several reasons. One reason is that sustainable construction principles may not be well understood by the design professionals undertaking the project. This could require time to be spent on research. Some of the finer points of LEED certification (especially those which demand a higher-than-orthodox standard of service from the construction team) could possibly lead to misunderstandings between the design team, construction team, and client, which could result in delays. Also, there may be a lack of abundant availability of manufactured building components which meet LEED standards. Pursuing LEED certification for a project is an added cost in itself as well. This added cost comes in the form of USGBC correspondence, LEED design-aide consultants, and the hiring of the required Commissioning Authority (CxA) (all of which would not necessarily be included in an environmentally responsible project unless it were also seeking LEED certification).
Often times when LEED certification is pursued, the initial construction cost of the project will be higher than the current industry standard. However, these high initial costs can be effectively mitigated by the savings incurred over time due to the lower-than-industry-standard operational costs which are typical of a LEED certified building. Additionally, economic payback may come in the form of employee productivity gains incurred as a result of working in a healthier environment. Studies have suggested that an initial up front investment of 2% extra will yield over ten times the initial investment over the life cycle of the building. [ [http://www.cap-e.com/ewebeditpro/items/O59F3259.pdf The Costs and Financial Benefits of Green Buildings] ]
Although the deployment of the LEED Standard has raised awareness of Green Building practices, its scoring system is skewed toward the ongoing use of fossil fuels. More than half of the available points in the Standard support efficient use of fossil fuels, while only a handful are awarded for the use of sustainable energy sources. Further the USGBC has stated support for the 2030 Challenge, an effort that has set a goal of using no fossil fuel green house gas emitting energy to operate by 2030. [ [http://www.architecture2030.org/2030_challenge/index.html The 2030 Challenge] ]
In addition to focusing on efficient use of fossil fuels, LEED focuses on the end product. For example, because leather does not emit VOCs they are deemed healthy for environments, disregarding the use of extremely harmful chemicals in the process of tanning leather. Other products that do not use harmful chemicals and focus on more sustainable production do not earn any additional points for their attention to environmental concerns.
Certification
Different LEED versions have varied scoring systems based on a set of required "prerequisites" and a variety of "credits" in the six major categories listed above. In LEED v2.2 for new construction and major renovations for commercial buildings there are 69 possible points and buildings can qualify for four levels of certification:
*Certified - 26-32 points
*Silver - 33-38 points
*Gold - 39-51 points
*Platinum - 52-69 pointsPoint rating
Points have been distributed as follows. Required "prerequisites" in each category receive no points. [cite web|url=http://www.usmd.edu/usm/sustainability/docs/UMB-LEED.ppt|title=LEED 2.2 for New Construction/LEED 2.0 for Existing Buildings |author=Ron Brown (UMB AEC)] cite web|url=http://www.aisc.org/Template.cfm?Section=Technical_Answers&template=/ContentManagement/ContentDisplay.cfm&ContentID=25766|title=Structural steel contributions toward obtaining a LEED rating May 2003 (rev. 2/04) Modern Steel Construction ] [cite web|url=http://www.ncmbc.us/docs/TheLEEDRatingSystem-ShelleyMcPhatter.pdf|title=The LEED rating system|author=Alan Jones]
Sustainable sites (14 points)
*Construction Activity Pollution Prevention Plan (required)
*Site selection (1 pt)
*Development density and community connectivity (1 pt)
*Brownfield redevelopment (1 pt)
*Alternative transportation availability (3 pts)
**Public transportation access (1 pt)
**Bicycle storage and changing rooms (1 pt)
**Parking capacity and carpooling (1 pt)
*Reduced site disturbance (2 pt)
**Protect or restore open space (1 pt)
**Development footprint
*Stormwater management (2 pts)
**Rate and quantity (1 pt)
**Treatment (1 pt)
*Reduce heat islands (2 pts)
**Roof (1 pt)
**Non-roof (1 pt)
*Light pollution reduction (1 pt)Water efficiency (5 points)
*Water efficient landscaping (2 pt)
**Reduce by 50% (1 pt)
**No potable use or no irrigation (1 pt)
*Innovative wastewater technologies (1 pt)
*Water use reduction (2 pt)
** (20%)
** (30%)Energy and atmosphere (17 points)
*Fundamental commissioning (required)
*Minimum energy performance (required)
*CFC reduction HVAC&R
*Optimize energy performance by 14% (new) or 7% (existing) buildings*Energy optimization (10 pts)
*On-site renewable energy (3 pts)
*Ozone depletion (1 pt)
*Measurement and verification (1 pt)
*Green power (1 pt)Materials and resources (13 points)
*Storage and collection of recyclables (required)
*Building reuse (3 pts):
**75% reuse of building structure and shell excluding windows (1 pt)
**100% reuse of building structure and 50% of walls, floors, ceilings (1 pt)
*Construction waste reuse or recycling (by weight or volume) (2 pts):
**50% diversion (1 pt)
**75% diversion (1 pt)
*Reuse of existing materials (by cost) (2 pts)
**5% salvaged or refurbished materials (1 pt)
**10% salvaged or refurbished materials (1 pt)
*Recycled content (2 pts)
**Criteria vary in recent versions of LEED, but depend on value of pre- and post-consumer recycled content (2 pt)
*Use of local materials (2 pts)
**Fabrication shop within 500 miles of building site and raw materials source within 500 miles of building site, 10% (1 pt) or 20% (+1 pt).
*Rapidly renewable materials (1 pt)
*Certified Wood (1 pt)Indoor environmental quality (15 points)
*Minimum indoor air quality (required)
*Environmental tobacco smoke control (required)
*Outdoor air delivery monitoring (1 pt)
*Increased ventilation (1 pt)
*Construction indoor air quality management (2 pt)
*Indoor chemical and pollutant source control (1 pt)
*Controllability of systems (2 pt)
*Thermal comfort (2 pt)
*Daylight and views (2 pt)Innovation and design process (5 points)
*Points for this category are awarded above and beyond the core 64 points, and are described as rewarding strategies that go above and beyond the criteria for those points. Examples for up to four design points using steel construction include structure as finish, structure as plumbing, lightweight materials, recyclability, and potential for disassembly.
Process
LEED certification is obtained after submitting an application documenting compliance with the requirements of the rating system as well as paying registration and certification fees. Certification is granted solely by the Green Building Council responsible for issuing the LEED system used on the project.
Recently the application process for new construction certification has been streamlined electronically, via a set of active PDFs that automates the process of filing the documentation.
LEED versions
Different versions of the rating system are available for specific project types: [ [http://www.usgbc.org/LEED U.S. Green Building Council: LEED] ]
*LEED for New Construction: New construction and major renovations (the most commonly applied-for LEED certification) [ [https://www.usgbc.org/FileHandling/show_general_file.asp?DocumentID=1096 LEED-NC Version 2.2 Registered Project Checklist] ]
*LEED for Existing Buildings: Existing buildings seeking LEED certification
*LEED for Commercial Interiors: Commercial interior fitouts by tenants
*LEED for Core and Shell: Core-and-shell projects (total building minus tenant fitouts)
*LEED for Homes: Homes
*LEED for Neighborhood Development: Neighborhood development
*LEED for Schools: Recognizes the unique nature of the design and construction of K-12 schools
*LEED for Retail: Consists of two rating systems. One is based on New Construction and Major Renovations version 2.2. The other track is based on LEED for Commercial Interiors version 2.0.LEED has evolved since its original inception in 1998 to more accurately represent and incorporate emerging green building technologies. LEED-NC 1.0 was a pilot version. These projects helped inform the USGBC of the requirements for such a rating system, and this knowledge was incorporated into LEED-NC 2.0. The present version of LEED for new construction is LEED-NC v2.2. LEED also forms the basis for other sustainability rating systems such as the Environmental Protection Agency's Labs21.
LEED is a popular guide for
green building in theUnited States and it is developed and continuously modified by workers in the green building industry, especially in the ten largest metro areas in the U.S.; however, LEED certified buildings have been slower to penetrate small and mid-major markets. [cite news|url=http://www.costar.com/News/Article.aspx?id=652024CBB8139C748C5F6F871CD4EF6B|title=LEED's Big Market Bias|publisher= CoStar Group|accessdate=2008-04-27|last= Burr|first= Andrew C.|date = April 23, 2008] Also, some criticism suggests that while the LEED rating system is sensitive to local environmental conditions, its checklist system does not vary by the local environmental conditions enough (for instance, a building inMaine would receive the same credit as a building inArizona for water conservation, though the principle is more important in the latter case). Another complaint is that its certification costs require money that could be used to make the building in question even more sustainable. Many critics have noted that compliance and certification costs have grown faster than staff support from the USGBC.In 2003, the
Canada Green Building Council received permission to create its own version of LEED based upon LEED-NC 2.0, now called LEED Canada-NC v1.0. [ [http://www.cagbc.org/uploads/FINAL_LEED%20CANADA-NC%201.0_Green%20Building%20Rating%20System.pdf Canada Green Building Council: Green Building Rating System] ]For existing buildings LEED has developed LEED-EB. Recent research has demonstrated that buildings which can achieve LEED-EB equivalencies can generate a tremendous ROI. In a recent white paper by the Leonardo Academy comparing LEED-EB buildings vs. data from BOMA’s Experience Exchange Report 2007 demonstrated LEED-EB certified buildings achieved superior operating cost savings in 63% of the buildings surveyed ranging from $4.94 to $15.59 per square foot of floor space, with an average valuation of $6.68 and a median valuation of $6.07. [http://mybuildingsuccess.com/index.php?option=com_content&task=view&id=46&Itemid=76 Going Green....Is it the 800lb Elephant in the Room?] ]
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