The recognition of our built environment as a cultural asset worthy of protection has stimulated corresponding legislation. In the listing process, heritage value has evolved from being a tool to determine the significance of buildings to becoming a selection criterion in legislation. However, value is open to interpretation, which leads to challenges of transparency, effectiveness, and the practical implementation of the protection process. We aim to better understand the scope and use of heritage value, in the context of the international debate and by tracing the historical development of the heritage conservation laws in Flanders and in Wallonia. The databases of the two agencies for immovable cultural heritage offered information on and access to protection rulings that reflect the practical implementation of heritage value criteria. Interviews with representatives involved in the listing process provided insights into the role of value as a legal tool. We then assessed the challenges and opportunities arising from applying value criteria. The ambiguity of value offers the possibility of discussing the adaptive reuse strategy in light of the current legal situation. We conclude that legislation must reflect the adaptive reuse strategy applied in practice to remain relevant and reflect the needs and views of society. ; This research project is funded by the Research Foundation Flanders (FWO) [G050519N].