Page 24 - The Engineering Guide to LEED-New Construction Sustainable Construction for Engineers

Intr oduction 7

system verbiage for each prerequisite and credit in this text and many of the tables,
definitions, and other information from the LEED-NC 2.2 Reference Guide.
LEED-NC 2.2 was the current version of the USGBC rating system for New
Construction and Major Renovations through April 2009, and may still be valid for
projects which registered prior to that date. The first edition of LEED-NC version 2.2
was released in October 2005. It replaced LEED-NC version 2.1 as the current rating
system for newly registered projects at that time. Since that time, there have been several
corrections and addenda to version 2.2, and a listing of these can be found as errata
available for download to the general public from the USGBC website. The first edition
of this text was based on the LEED-NC version 2.2 released in October 2005 and as
amended through the second edition dated September 2006 and errata as posted in the
spring of 2007. This second edition still not only covers most of the LEED-NC 2.2
version, but also includes the new LEED-NC 3.0 version for New Construction and
Major Renovations, commonly referred to as LEED-NC 2009. The modifications are
based on the LEED Reference Guide for Green Building Design and Construction, 2009
Edition published by the USGBC. This 2009 Reference Guide covers the 2009 New
Construction flagship rating system (LEED-NC 2009) as well as two other USGBC
rating systems for new construction, LEED for Schools (K–12) and also LEED for Core
and Shell projects (LEED-CS), both also part of the LEED version 3.0 group. There have
been many changes to the LEED-NC rating system between versions, and released as
errata or addenda during the versions. Practitioners and educators should ensure that
these changes are incorporated in future projects and class curricula.
This text focuses on the LEED-NC rating system, which is a premier and heavily used
green rating system in the United States. LEED-NC is for new construction and major
renovations for mainly commercial, institutional, industrial, and large residential (four
stories or more) projects. The USGBC and several other organizations have also developed,
or are in the process of developing, rating systems for other types of projects. One other
organization of note is the National Association of Home Builders (NAHB), which
through the GBI is offering its voluntary Model Green Home Building Guidelines. Some
of the other LEED rating systems are listed in Table 1.1.1.
Sustainability is not just an environmental concept. Many are quick to point out that
sustainability focuses on a triple bottom line: economic, environmental, and societal.
Many of the concepts relating to future economic and societal concerns are dependent
on current resource and environmental management and best practices. Hawken,
Lovins, and Lovins further expand on this in their book Natural Capitalism, Creating the
Next Industrial Revolution.

1.2 Introduction to the USGBC LEED-NC Rating System
LEED-NC is applicable to a large portion of the most expensive vertical construction
projects in the United States. It basically covers most commercial, institutional, and
industrial projects and includes residential construction of facilities of four or more
stories.
Guidances
There are many projects which have unique criteria that may not fit well into the credit
intents and requirements as listed in LEED-NC 2.2 or 2009. To facilitate LEED certification
and sustainable practices for certain categories of projects, the USGBC has developed or
is developing guidances specific to many special subsets of project application types.