This paper explores the spatial and temporal patterns of green building in the commercial and institutional sector in the U.S. While these buildings are becoming more common place, they have yet to reach a critical mass to affect the entire construction industry. Given the potential for green building practices to reduce energy consumption and carbon emissions, we seek to understand the geography of green building. Using multiple metrics, we explain the patterning of geography of LEED and Energy Star certified buildings in the United States. We find strong evidence of clustering at the metropolitan and sub-metropolitan scales. This exploratory research serves as a foundation for future research aimed at specifying the nature of agglomerative processes in green buildings.