Louis Kahn’s Richards Medical Laboratories underwent a two-phased renovation (2013-2015 & 2019), driven by University of Pennsylvania’s Century Bond program’s energy-saving objective. A national historic landmark, a Modernism masterpiece and a heavy equipment-bearing facility, the building had to meet satisfactory results for all the criteria as strict as possible: preservation, Modernism and sustainability. Every Mid-Century rehabilitation project accommodates similar requirements, Richards’ renovation provides a stringent example for others to reference upon. Thus a prudent review on what guidelines suggested, architects and engineers proposed and executed, post-renovation data and findings yielded, are crucial in forming a holistic apprehension. In Richards renovation, an upgrade on HVAC systems, an evaluation on historic monolithic single-pane glass, and eventually repurposing the building are the major renovation strategies. All of the strategies are for sustainability goals but also had to address specific design intention and significance Kahn left. In parallel to Richards, two comparable case studies, Penn’s Evans Dental Building renovation, also a Century Bond program project, and Yale University Art Gallery, also rehabilitated Kahn’s single-pane glass, provided comprehensive information for complementary purposes. The information induced could serve as an epitome for projects of similar context and restrictions.