THE LIMITATIONS OF LEED: A CASE STUDY

INTRODUCTION

The Xanterra houses are situated against the backdrop of one of America's most spectacular natural landscapes, just a few hundred yards from the north entrance to Yellowstone National Park. The project consists of two single-family homes for seasonal workers, approximately 2000 square feet each. They are mirrored east-to-west but otherwise identical (see Figure 1). The project was completed in 2003, and certified under LEED-NC v2.0, project #1353 on December 10, 2004—the first building project in the National Park system to receive LEED (Leadership in Energy and Environmental Design) certification from the USGBC (United States Green Building Council). 1

The houses were built with the explicit intent that they would become a model for future green building projects at Yellowstone and other national parks, 2 and the project team felt it was fitting that these houses be situated in the nation's first national park. Indeed, they were fundamentally well-designed and constructed, and they incorporated some of the latest technologies for saving energy and water, authentically earning the label “high-performance.” Yet the project only earned the lowest possible rating (“certified”) from LEED, meaning it is barely considered green. This paper documents the green design strategies through the design and construction process, with special attention paid to the influence of the LEED scorecard on collaborative decision-making and to the difficulties this project encountered during the LEED assessment process. Few academic studies have examined the process of LEED self-reporting and scoring within a professional setting, 3 even though contingencies such as common business practices and human limitations clearly affect a project's LEED score.

This paper will show that the LEED scorecard turned out to be a poor assessment tool in this case study, because the reporting procedure inaccurately reflected the architectural design and construction. Furthermore, there have been a few important papers that conclude that a major problem of the LEED rating method is its failure to account for the building's performance over its projected life. 4 This paper will verify those conclusions by showing that the lifespan of concrete construction was not considered by the LEED rating process.

The larger questions that stimulated this research are consistent with the problems that have motivated the current widespread interest in green design strategies: How can we design buildings that consume less energy? How can we use materials and construction practices more responsibly in terms of reducing pollution and waste? How should we evaluate our own practices to understand their true efficacy? These questions are particularly urgent for the American homebuilding industry, which has become increasingly extravagant and has lost sight of green design strategies in the design of its dwellings 5 (and increasingly wasteful in energy consumption). Since the Xanterra houses were consciously developed as a positive alternative to typical homebuilding practices, an analysis of their performance—from design through assessment—may have implications for future projects of a similar type.