Completing a retrofit or refurbishing an existing historical building improves building energy performance and tenant satisfaction. Existing buildings that pursue LEED certification as part of this process implement modifications that improve energy efficiency, indoor air quality, water reduction, and tenant satisfaction to name a few. These buildings can reduce operational costs, attract tenants, and create increased productivity. We look to provide a robust discussion around how to pursue strategies to decarbonize your building by completing a green retrofit and why LEED is a great tool to support these strategies.