Regarding: LEED-NC (v2.1 and v2.2) SS Credit 2 - Urban Redevelopment/Development Density/Development Density & Community Connectivity LEED-CI SS Credit 2 - Development Density and Community Connectivity The LEED-CIv2.0 Reference Guide (p.85) states that "no exemplary performance criteria exist" for this credit. Similarly, the LEED-NCv2.2 Reference Guide (p.37) states that "there is no exemplary performance point available for this credit." This guidance may have been based on the conception that this credit is a "pass/fail" type credit. The conception that it is a pass/fail item may be based on the belief that there is no easily measurable way to determine what would constitute exemplary performance with respect to the intent of the credit. The intent of the credit for both the NC and CI versions of the credit is "Channel development to urban areas with existing infrastructure, protect greenfields, and preserve habitat and natural resources." This CIR is a request that the SS TAG reconsider the approach previously taken to this credit, and consider granting an exemplary performance point (via the Innovation Credit category) to projects which substantially exceed the threshold of the credit. Exemplary performance towards the intent of protecting greenfields, preserving habitat and natural resources is possible and measurable for the following reasons: 1. Increased density of the project conserves more land; square footage that is built in multi-story buildings would otherwise be built in less dense buildings, consuming more land, sometimes in previously undeveloped areas. 2. Similarly, increased density of the project conserves more undeveloped watershed, and therefore reduces the impact on receiving water bodies. Locating a project in a more dense surrounding area, on average, decreases the number of vehicle miles traveled (VMT) associated with the project. Research shows that for every doubling of density, there is a 20-40% reduction in VMT per capita. (Sources: John Holtzclaw, et al, "Location Efficiency: Neighborhood and Socio-Economic Characteristics Determine Auto Ownership and Use: Studies in Chicago, Los Angeles, and San Francisco," Transportation Planning and Technology, Vol. 25, 2002; Michael Bernick and Robert Cervero, Transit Villages In the 21st Century, New York: McGraw-Hill, 1997. Susan Handy, How Land Use Patterns Affect Travel Patterns: A Bibliography, Council of Planning Librarians, 1992.) Increasing density improves the viability of transit and walkable options. Please note, much of this research focuses on studying residential density, but the research on commercial density has shown that it increases transit ridership as well. Decreases in VMT then translate directly into less energy consumption.
[Revised November 14, 2006, to correct calculations in requirements] Based on evidence that higher density locations can achieve substantially and quantifiably higher environmental benefits, the following threshold requirements can be used to qualify a project for an exemplary performance Innovation Credit: -- A LEED-NC project must first meet either the requirements of SSc2 in LEED-NC v2.1 or Option 1 of SSc2 (density path) in LEED-NC v2.2. Additionally, the project must meet one of the two following requirements: a) The project itself must have a density of at least double that of the average density within the calculated area (see equation 2). OR b) The average density within an area twice as large as that for the base credit achievement must be at least 120,000 square feet per acre. To double the area, use equation 2 but double the property area first. -- A LEED-CI project must first meet the first compliance path (density) in SSc2 of LEED-CI v.2.0 (LEED-CI pilot projects may use the LEED-CI pilot version of SS Credit 2). Additionally, the average density of the area within an area twice as large as for the base credit achievement must be at least 120,000 square feet per acre. -- These requirements are based on the decision that a project achieving exemplary performance for this credit (1) should not lower the existing average density of the area, (2) should achieve a density of at least twice the threshold of the base credit, and/or (3) should locate within an area of established density that is larger than that required for the base credit, which is why the radius used in the base credit has been doubled. Applicable internationally.
Related Addenda (Corrections & Interpretations)