There has been an increasing demand for maximizing the environmental, social, and economic value of our built infrastructure for supporting sustainable construction. However, a major gap still exists in the areas of value analysis; there is no formal model to conceptualize, represent, and reason about value and valuation of our built infrastructure. This paper presents our work in the area of formal axiology-based, sustainability-oriented value analysis of building projects. "Axiology" is a theory of values and worth. Our formal axiology is a theory-based, semantic model for analyzing and assessing the value (worth) of building projects on the basis of environmental, social, and economic values of stakeholders (e.g., energy conservation, safety, economic growth). The first step toward developing our formal axiology is discovering stakeholder values in the context of building projects. Value discovery is the process of identifying the values that are relevant to a particular system. In this paper, we focus on presenting our value discovery work for educational building projects. We discovered stakeholder values from project documents and value literature, and from using stakeholder questionnaire surveys. The paper discusses the questionnaire design, survey results, results analysis, and conclusions in terms of how educational building projects are related to the environmental, social, and economic values of stakeholders. The paper also presents the modeling of these discovered values in the form of a concept hierarchy (taxonomy) as part of our formal axiological modeling.