Many people know the term LEED and associate it w/ words like “green” and ”sustainability.” Given yesterday’s post on the Siemen’s Sustainable Cities Index, which utilized the LEED certification (Silver, Gold or Platinum) per 100,000 people as a contributing statistic to the index, I thought it appropriate to expand a little bit on LEED and talk about why it matters.

First things first. LEED stands for Leadership in Energy and Environmental Design, and it refers to an internationally recognized rating system developed by the US Green Building Council (USGBC) in 2000 to provide building owners and operators with a framework for identifying and implementing practical and measurable green building design, construction, operations and maintenance solutions. There are four different tiers of LEED Certification: Ceritified, Silver, Gold, and Platinum. Given the unique characteristics inherent in different building types and uses, the USGBC developed tailored rating systems for the following building/design categories:

• New Construction (NC)
• Existing Buildings: Operations & Maintenance (EB: O&M)
• Commercial Interiors (CI)
• Core & Shell (CS)
• Schools (SCH)
• Retail
• Healthcare (HC)
• Homes
• Neighborhood Development (ND)

The different rating systems continue to evolve, but concentrate around the same core concepts:

• Sustainable Sites - this refers to things like focusing development on areas in which there is existing transportation and community infrastructure, as well as access to alternative means of transportation, so as to further enable mass transit over auto transit and reduce development of greenfield areas (not an issue here in NYC). 
• Water Efficiency - this refers to things like water use reductions, efficient landscaping, innovative wastewater technologies, etc.
• Energy & Atmosphere - this refers to efficient HVAC systems, onsite renewable energy systems, refrigerant management, and so on.
• Materials & Resources - this category looks specifically at building materials, how much energy is expended to bring them to the site (i.e., were any materials reused or locally sourced? this would lower the CO2 footprint of any building), are the materials rapidly renewable, etc.
• Indoor Environmental Quality - this category deals w/ the chemical nature of the materials and surfaces in the building, controllability and thermal comfort for building residents (it can be highly inefficient to have a number of different people turning the heat up and down; these inefficiencies can be reduced if individual users have more control over their local lighting and thermal systems), and so on. 
• Innovation in Design & Regional Priority - because the LEED credit system is ever-evolving, USGBC leaves room for innovative strategies that go over and above the the requirements in particular categories and/or that uniquely achieve significant and measureable environmental benefits.

According to the Index, NYC had 1.1 LEED Certified (Silver, Gold, or Platinum) Buildings per 100,000 people, which was well below the 6.4 average for the Index.