The principles of future-proofing are derived through a literature review of the use of the terms “future-proofing” and “resiliency” in the architecture, engineering, and construction (AEC) industry and other industries such as electronics and environmental design. The principles are focused on application to the preservation of historic buildings and are demonstrated through a case study of the 1980-2000 walrus head and tusk repairs at the Arctic Building in Seattle, Washington. The principles assist in consideration of the best practices for the treatment of an historic building by establishing a baseline series of criteria by which to evaluate interventions in historic buildings.