The concept of value seems to have capital importance both in the scientific literature and in various heritage actors’ professional discourse. The actions undertaken to develop the built environment inherited from previous generations seem to depend on thevalue we assign it. In this essay, the concepts of value, assessor, and heritage assessment are discussed. Two historical contexts are compared: the classical axiology of the 19th century based on the Enlightenment search for rationality and the typologies of contemporary values struggling with complexity. This historical reassessment shows a complexification and multiplication of evaluation grids, as well as the need to question the subjectivity inherent in heritage actors’ decisions. In order to not sink into excessive relativism definitively discrediting any attempt to make the process of heritage assessments more objective, a dynamic point of view is proposed, linking the constructivist approach with the use of a criteria-based value grid.