The LEED family of rating systems uses specific terms to describe various aspects of its program. Whether you are a designer, contractor, consultant, manufacturer, educator, or owner, it is important to be clear and consistent about these terms. Becoming familiar with these terms is also a great way to gain a basic understanding of LEED.

LEED: Short for “Leadership in Energy and Environmental Design.” Don't call it “Leeds”—that’s a city in England. LEED is a voluntary (except when required by specific municipal programs, or in government buildings) program meant to objectively measure how "green" or environmentally friendly a building is in several key areas: impact on site, water efficiency, energy efficiency, materials selection, and indoor environmental quality.

USGBC: The U.S. Green Building Council is the nonprofit, nongovernmental, membership-based organization that conceived of LEED, and continues to support the LEED Rating System.

GBCI: Green Business Certification Inc. is the nonprofit organization that is in charge of accrediting LEED professionals and certifying LEED buildings (see more on these terms below). GBCI is very closely connected with USGBC—some people refer to the two organizations interchangably—but basically, USGBC maintains the LEED rating system, and does a lot of other stuff (like advocating for green building policies), while GBCI enforces rules related to LEED. (Note: until 2015, GBCI was "Green Building Certification Institute.")

LEED certification: Buildings become “LEED certified” by completing the registration and documentation requirements and receiving official certification from the Green Building Certification Institute (GBCI). Certified buildings may display a LEED plaque.

LEED registration: Before they become certified, projects must have registered with GBCI in order to submit their documentation. A LEED-registered project may be in the process of pursuing certification, but is not considered certified.

LEED Online: LEED Online is the Web-based portal where LEED projects register and where they complete and upload documentation for certification. There are currently three active versions of LEED Online: LEED Online v2, LEED Online v3, and the most recent version, which is simply called LEED Online. LEED Online includes campus projects, which previously had their own version, called LEED Online for Campus.

Certification levels: LEED projects can be certified at one of four levels: 1.) Certified 2.) Silver 3.) Gold 4.) Platinum. Check that: lower-case "certified" could be any of four levels, while upper-case "Certified" refers specifically to the lowest level. It is common to achieve Silver certification, while Gold and especially Platinum are more out of reach.

LEED accreditation: Professionals in the building industry who learn about green building and LEED and pass an exam can become “LEED-accredited” and use the credentials “LEED AP” (for LEED Accredited Professional), or LEED Green Associate. The LEED AP credential is for designers, contractors, and other members of a project team who have LEED experience, while the LEED Green Associate credential is intended for sales reps and other associated professionals. LEED AP credentials come with a specialty, such as BD+C, for "Building Design and Construction," signifying an expertise in the new construction side of LEED.

Building products: Building manufacturers sometimes want to get their products, assemblies, or building systems “LEED certified.” However, products cannot be LEED certified or otherwise preapproved for LEED. They can only contribute to the earning of specific LEED credits and therefore to the certification of a project. Many building products and materials can contribute to earning LEED credits in one way or another. See LEEDuser's specific LEED credit guidance for more.

LEED prerequisite: A section of a LEED rating system with specific intent and requirements that must be met for a project to become certified. Missing even one prerequisite will disqualify a project from LEED certification. If planned for, prerequisites are typically very easy to achieve.

LEED credit: A section of a LEED rating system with specific intent and requirements that a project can meet to earn one or more points toward certification. Credits are typically more challenging than prerequisites and represent greater-than-standard practice. By definition there are no required credits, but to achieve any level of LEED certification some credits must be earned, and achieving a high LEED score means achieve many or most available credits.

LEED 2009: Launched in 2009, this version of LEED encompasses several different LEED rating systems. Registration for LEED 2009 closes in June 2015. LEED 2009 is sometimes referred to as LEED v3. A few LEED rating systems (Existing Buildings, Homes) also have a "2008" iteration.

LEED v4: Originally referred to as LEED 2012, the name of LEED v4 changed when its launch was pushed to November 2013. LEED v4 includes many new and revised LEED credits and prerequisites.

LEED rating systems (as of LEED 2009): LEED certification can apply to a whole building, whether new or existing, with different versions of the rating system applying to new construction and major renovations (LEED for New Construction, or LEED-NC), or operations and maintenance (LEED for Existing Buildings: Operations & Maintenance). Certification can also apply to tenant improvements using the LEED for Commercial Interiors (LEED-CI) rating system, even if they don’t encompass an entire building. Entire neighborhoods can also be certified under LEED for Neighborhood Development (LEED-ND). Certain specific building types are addressed through rating systems such as LEED for Healthcare and LEED for Schools, which are modified versions of the more generic LEED-NC.

LEED rating systems (as of LEED v4): As a way of dealing with the proliferation of LEED rating systems, USGBC officially consolidated the number of rating systems to four in LEED v4:

• LEED for Building Design & Construction (LEED BD+C)
• LEED for Interior Design & Construction (LEED ID+C)
• LEED for Building Operations & Maintenance (LEED O+M)
• LEED for Neighborhood Development (LEED ND)

LEED rating system adaptations (LEED v4): With the consolidation that took place with LEED v4, USGBC is currently referring to specific rating systems for individual building types as "adaptations." The following is a complete list of LEED v4 rating system adaptations. These are the specific LEED rating systems that individual projects will use.

• LEED for Building Design & Construction: New Construction and Major Renovations
  • Abbreviations: LEED BD+C: New Construction, or BD+C: NC
• LEED for Building Design & Construction: Core and Shell Development
  • Abbreviations: LEED BD+C: Core and Shell, or BD+C: CS
• LEED for Building Design & Construction: Schools
  • Abbreviations: LEED BD+C: Schools, or BD+C: S
• LEED for Building Design & Construction: Retail
  • Abbreviations: LEED BD+C: Retail, or BD+C: R
• LEED for Building Design & Construction: Healthcare
  • Abbreviations: LEED BD+C: Healthcare, or BD+C: HC
• LEED for Building Design & Construction: Data Centers
  • Abbreviations: LEED BD+C: Data Centers, or BD+C: DC
• LEED for Building Design & Construction: Hospitality
  • Abbreviations: LEED BD+C: Hospitality, or BD+C: HO
• LEED for Building Design & Construction: Warehouses and Distribution Centers
  • Abbreviations: LEED BD+C: Warehouses and Distribution Centers, or BD+C: WDC
• LEED for Building Design & Construction: Homes and Multifamily Lowrise
  • Abbreviations: LEED BD+C: Homes, or BD+C: H
• LEED for Building Design & Construction: Multifamily Midrise
  • Abbreviations: LEED BD+C: Multifamily Midrise, or BD+C: MR
• LEED for Interior Design & Construction: Commercial Interiors
  • Abbreviations: LEED ID+C: Commercial Interiors, or ID+C: CI
• LEED for Interior Design & Construction: Retail
  • Abbreviations: LEED ID+C: Retail, or ID+C: R
• LEED for Interior Design & Construction: Hospitality
  • Abbreviations: LEED ID+C: Hospitality, or ID+C: HO
• LEED for Building Operations & Maintenance: Existing Buildings
  • Abbreviations: LEED O+M: Existing Buildings, or O+M: EB
• LEED for Building Operations & Maintenance: Data Centers
  • Abbreviations: LEED O+M: Data Centers, or O+M: DC
• LEED for Building Operations & Maintenance: Warehouses and Distribution Centers
  • Abbreviations: LEED O+M: Warehouses and Distribution Centers, or O+M: WDC
• LEED for Building Operations & Maintenance: Hospitality
  • Abbreviations: LEED O+M: Hospitality, or O+M: HO
• LEED for Building Operations & Maintenance: Schools
  • Abbreviations: LEED O+M: Schools, or O+M: S
• LEED for Building Operations & Maintenance: Retail
  • Abbreviations: LEED O+M: Retail, or O+M: R
• LEED for Neighborhood Development: Plan
  • Abbreviations: LEED ND: Plan, or ND: Plan
• LEED for Neighborhood Development: Project
  • Abbreviations: LEED ND: Project, or ND: Project

LEEDuser: One last term. This website is a support tool for projects seeking LEED certification. It consists of extensive guidance on achieving LEED credits and prerequisites that is available to members, as well as a discussion forum available for free.

There are plenty of other key LEED terms—in fact, we have a whole LEED glossary embedded in this site, but this post is meant to provide a high-level introduction to key concepts. What are your questions? What misconceptions about LEED do you encounter? What key terms would you add? Please add your comments below.

Thanks to my colleague Nadav Malin for writing many of the above descriptions.