The purpose of this research is to discover the needs a value assessment and the preceding research should fulfill, so that they may serve as a useful framework for the development and reviewing of a conservation plan for a monument. This objective has been prompted by recent developments in Dutch conservation practice and the demand resulting from this for a new understanding and process of valuation for built heritage. In the Netherlands, but also elsewhere, the development of the valuation of monuments kept pace with the emergence, development and institutionalization of built heritage conservation. Various social, political, economic and scientific developments, inside and outside the field of conservation, led up to the emergence of value assessment, in the sense of explicitly naming the values of a monument and methodically founding a value-based judgment as the basis for the monument’s conservation. Social, political and economic developments still influence the discussion about the how and why of value assessment. In addition, new insights and ideas from the art historical and architectural disciplines, and from other professional and academic fields related to the conservation of cultural heritage, are reflected in the way value assessment is approached and such an assessment is used in heritage conservation. To arrive at a contemporary approach to value assessment, it is important to look back at the past of values, valuation and value assessment, on the results it yielded us so far and the direction where it can or should go. Therefore, this thesis focuses on why and how value assessment emergence, how it developed, how it was used in the practice of built heritage conservation and which demands are currently made on the content and the procedural embedding of a value assessment and its preceding research. To that purpose, the following research questions are formulated: • What was the reason for the emergence of the instrument value assessment and how did it develop? • How was a value assessment ...