The Northeast-Midwest Institute (NEMW) is using the term "sustainable urban redevelopment" as a generic term to describe development that is green and energy-efficient, both internally within the building envelope and externally, in that there are energy savings by virtue of the project location and its relationship to the city. This dual benefit is key. Generally, green/energy-efficient buildings are designed to save about 30 percent on energy use within the structure. Post-construction studies of Leadership in Energy and Environmental Design (LEED)-certified projects confirm that level of energy savings. Externally, "compact urban development" saves 20 to 40 percent of vehicle miles traveled (VMT) with corresponding reductions in greenhouse gases (GHGs). Brownfields, as a subset of urban redevelopment, have been shown to have similar VMT-related energy benefits. When redevelopment projects combine both elements (VMT reduction and energy-efficient buildings), the energy savings can be estimated to be 30 to 35 percent of the total energy demands attributable to the development, relative to conventional construction in suburban auto-dependent locations. While this is a considerable documented energy benefit, there are other factors not accounted for which may cause the percentage reduction to go even higher. Not taken into account in the above calculation are the following factors: 1. Urban density is associated with energy efficiencies within the building due to fewer exposed surfaces. 2. There is less "line-loss" in distributing electricity to dense urban areas than to spread suburban areas. 3. Less energy is spent in building and maintaining infrastructure for urban projects than suburban sprawl projects. 4. Some urban projects are served by waste-to-energy plants or district heating systems that also lower GHGs. 5. An indirect benefit of urban redevelopment is the retention of greenfield "carbon sinks." While these latter factors remain insufficiently quantified (and further study is recommended), the previous point-the dual benefit of energy savings within the building envelope and VMT reduction - makes a sufficiently strong case that promotion of sustainable urban redevelopment can be a major source of greenhouse gas reduction.
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