The Air Force Academy Cadet Chapel—an iconic and landmarked structure—has experienced water leakage since it was built in 1963. The unique skin on the repeating tetrahedrons is sloped, with exterior water drainage and management behavior somewhere between a wall and a roof. This study will review the existing detailing conditions resulting in water leakage. A reclad design was developed to incorporate a new weather-resistant panel backup wall and inboard metal cladding panels matching the existing historical appearance. The building science principles governing the design development are examined. To evaluate the design, a laboratory mock-up was constructed and performance tested. Challenges related to acquiring and constructing the custom repair design skin assemblies for a full-scale laboratory mock-up will be reviewed. Performance testing of the design included rounds of air, water, thermal, and structural load testing. Lessons learned from the performance testing and the resulting design modifications will be presented.