LEED 2009 Recertification of Existing Buildings: Bonus Effect

This study aimed to assess the impact of a four-point bonus system on recertification in Leadership Energy and Environmental Design for Existing Buildings (LEED-EB) 2009 office space projects four metropolitan cities: Washington, DC, Chicago, New York, San Francisco. We analyzed 123 paired LEED-EB where each pair (i.e., certification–recertification) was used same building. The percentage average score evaluate differences certification–recertification strategies: (1) gold-gold with without bonus, (2) silver-gold (3) platinum-platinum bonus. replication method overall tendency cities. found that while achievements materials resources (MR) indoor environmental quality (EQ) categories declined identified this at three levels certification–recertification: gold-gold, silver-gold, platinum-platinum. hypothesized if use resulted lower MR/EQ categories, then 10-point 4.1 could lead deterioration sustainability existing buildings.