Leadership in Energy and Environmental Design (LEED)
The Leadership in Energy and Environmental Design (LEED) program is an internationally recognized building certification program for architects, contractors, owners, and operators (see Appendix H). It provides a framework for building design, construction, operation, and maintenance to achieve reduction in environmental impacts and improvement in conditions for building occupants. To guide design of building sustainability, design criteria from the U.S. Green Building Council’s (USGBC) LEED certification program will be used (USGBC 2011a).
LEED has evolved since 1998 to more accurately represent and incorporate emerging green building technologies. The pilot version, LEED New Construction (NC) v1.0, led to LEED NCv2.0, LEED NCv2.2 in 2005 (USGBC 2011b), and LEED 2009 (previously named LEED v3) in 2009. LEED v4 was introduced in November 2013. Until 31 October 2016, new projects could choose between LEED 2009 and LEED v4. New projects registering after 31 October 2016 have been required to use LEED v4.
The LEED rating system is meant for new and existing commercial, institutional, and residential buildings, and also for entire neighborhood developments. There are currently over 800 LEED‐qualified buildings in the United States (USGBC 2011c). There are separate rating systems for different building types and projects.
LEED 2009 encompasses 10 rating systems for the design, construction, and operation of buildings, homes, and neighborhoods. Five overarching categories correspond to the specialties available under the LEED professional program. That suite currently consists of the following:
- Green building design and construction
- LEED for new construction
- LEED for core and shell
- LEED for schools
- LEED for retail: new construction and major renovations
- LEED for healthcare
- Green interior design and construction
- LEED for commercial interiors
- LEED for retail: commercial interiors
- Green building operations and maintenance
- LEED for existing buildings: operations and maintenance
- Green neighborhood development
- LEED for neighborhood development
- Green home design and construction
The LEED for homes rating system is different from LEED v3, with different point categories and thresholds that reward efficient residential design.
Each rating system listed includes five environmental categories: sustainable sites, water efficiency, energy and atmosphere, materials resources, and indoor environmental quality. Two additional non‐environmental human effects categories are also included in the rating system: innovation in design and regional priority.
In the LEED rating system, each category is subdivided into “credit” subcategories, and one or more points are assigned to each credit subcategory. Total possible points; however, 10 additional points can be awarded for the innovation in design and regional priority categories. The allocation of points among the credit subcategories is based on an analysis of potential environmental impacts and human benefits relative to a set of impact indicators. These impact indicators include GHG emissions, fossil fuel use, toxins, carcinogens, air and water pollutants, and indoor environment. The assessment of potential environmental impacts uses the TRACI impact assessment model from the USEPA (see Sections 6.3.12, 6.4.3.7, and 6.4.3.8) and then applies additional weightings to each subcategory credit from the National Institute of Standards and Technology (NIST), similar to the way that weightings are applied in LCA (see Chapter 6). The decision on how many points to assign to each credit subcategory is based on a consensus process with a committee of sustainability experts.
The USGBC LEED Program certifies that building projects achieve certain levels of desired outcomes according to a numerical scale. For example, in retail applications, the following point scale applies to both design and construction phases:
Leave a Reply