Assessing Existing Buildings for LEED Retrofit: Case Study of a University Building M. Oytun, B.A. Bilginer and G. Atasoy Middle East Technical University, Civil Engineering Department, Ankara, Turkey moytun@metu.edu.tr, aykutb@metu.edu.tr, guzide@metu.edu.tr Abstract The sustainable built environment concept gained significant attention from the scientific community due to the tremendous increase in the emission of greenhouse gases triggered by the exploitation of natural resources. Changing the conventional way of building construction and retrofit into a greener one is an indispensable step to ensure a sustainable built environment as the buildings cover most of the surrounding. Accordingly, Architecture Engineering and Construction (AEC) industry has started to incorporate green building rating systems like LEED and BREAM in past decades. In this context, accreditation systems have been used in many countries, for both new and existing buildings. The purpose of this study is to assess an existing university building’s sustainability potential. First, the current condition of the building is examined using a LEED checklist. Then alternative retrofit strategies, considering potential improvements, are identified from the Life Cycle Cost (LCC) and cost efficiency perspectives. Based on the findings, investing in buildings’ sustainability can easily be compensated, as it leads to a remarkable reduction in resource allocation in the long run. Especially, from the cost-efficiency perspective, location and transportation, and indoor environmental quality-related improvements are leading solutions while water and energy efficiency-related improvements are prominent when LCC is considered. Keywords: Campus Building Renovation, Green Building Certification, LEED, Life Cycle Cost, Retrofit