Just as architectural history traditionally takes the form of a march of styles, so too do preservationists repeatedly campaign to save seminal works of an architectural manner several decades after its period of prominence. This is currently happening with New Brutalism and given its age and current unpopularity will likely soon befall postmodern historicism. In hopes of preventing the loss of any of the manner’s preeminent works, this study provides professionals with a framework for evaluating the significance of postmodern historicist designs in relation to one another. Through this, the limited resources required for large-scale preservation campaigns can be correctly dedicated to the most emblematic sites. Three case studies demonstrate the application of these criteria and an extended look at recent preservation campaigns provides lessons in how to best proactively preserve unpopular sites. It has repeatedly been shown that tastes change, but seminal works of a style or manner are often lost before this occurs. Through creating a model for proactive preservation of postmodern historicism, this study seeks to ensure none of the manner's most valuable sites are lost.