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with 200,000 square feet of parking and 10,000 square feet of occupied space and achieve LEED certification. However, is such a project a LEED garage or a small LEED project with a very large adjacent garage? While such an endeavor is a well meaning attempt to reduce the environmental footprint of the structure and is informed by the best available tools to date, is this the correct path to create a “green garage”? As mentioned previously, LEED 2009 re-weighted all of the credits to account for overall environmental impact—top priorities being addressing energy use and carbon emissions. However, in comparison to most structures, parking facilities use very little energy. An office building uses five times as much electricity as a parking garage of the same square footage. Therefore, is decreasing the energy use of a parking garage as important as it is in an office building? There are also some LEED credits that parking facilities likely capture by default. For example, the most common material used to construct a parking garage is concrete. Concrete is almost always a regional material (defined by

pavements, efficient facility lighting, and the inclusion of bio-swales or rain-gardens on the project site. While some of these strategies can garner LEED credits, others are “beyond LEED” and are generally incorporated only by forward-thinking owners and design teams. One sustainable design strategy for parking garages that goes “beyond LEED” is the use of smart parking technologies. While this may not be one of the most obvious approaches to sustainable design, smart parking technologies can move cars to their spaces faster, thus reducing trip times and carbon emissions. Another consideration is how the parking facility interacts with its surroundings. For example, a garage in a metropolitan area with ground floor retail makes the surrounding streets more walkable than one with ground floor parking. Similarly, since parking garages do not need to be above ground, they have the unique ability to create space on the roof or above the garage that can improve the immediate surroundings. An example of this can be seen with Discovery Green in Houston.

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LEED as “sourced within 500 miles of the site”) and can have a large recycled content based on the recycled content of rebar and the use of cement replacement materials. This means it is possible to achieve “exemplary performance” LEED points by following standard practice. Once we acknowledge that LEED was not designed for parking facilities, we can accept that attempting to apply their rating system to parking garages is much like trying to fit a square peg into a round hole. It can result in achieving credits for simply following standard practice, while missing other garage-specific sustainable strategies that can make a meaningful difference. In addition, forcing the system to work for parking garages confuses owners and creates skepticism among those knowledgeable about sustainable design. Does this mean that parking garages cannot be green and cannot be built in a sustainable way? The answer is “No.” In their 2009 PARKING article “Going Green,” Dennis Burns and Gary Cudney suggested several ways that parking structures can incorporate sustainable design elements, such as providing support for transportation alternatives, green roofs and parking canopies, “cool”

Smart parking technology at Tampa International Airport helps parkers reach their spaces faster and eliminates unnecessary travel, and emissions, within the garage. Photo Courtesy Gresham Smith and Partners.

Unlike most structures where the operational energy can far outweigh the embodied energy, parking structures experience the reverse, with regard to energy and carbon emissions. Therefore, the emphasis on energy reduction should be on the embodied energy in the structure. To illustrate why one should pay particular attention to the embodied energy in a parking garage, the embodied carbon within the structure, in the cement alone, could be more than the operational carbon resulting from over 10 years of the lighting energy. However, this embodied energy can be drastically reduced by innovative design and construction teams willing to push the limits of cement replacement. The challenge faced today by garage designers—establishing what defines a green garage—is similar to the challenge faced by healthcare designers approximately eight years ago. At that time, LEED was gaining popularity, and while it could be applied to hospitals, it was not developed for that building type. Some LEED credits were not
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July/August 2010 Parking

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