Historical buildings are unique assets in any society, embodying cultural significance and architectural heritage. Denmark, with its rich architectural background, has taken steps to preserve these values. As the imperative of sustainability continues to grow, recognizing the social, economic, and environmental values of historic buildings is becoming increasingly important. As an important step towards adapting sustainability certification systems for historic buildings in order to identify and preserve their historical values, this paper aims to conduct a comparative analysis between the GBC and HB (Green Building Council–Historic Building), which has been adapted for historic buildings in Italy and the Danish GBC system (GBC-DK or so-called DGNB-DK). The study is based on a theoretical framework underpinned by a systematic approach utilizing a qualitative comparative analysis (QCA) alongside the triangulation method. This includes a systematic literature review comparing the GBC-DK and GBC-HB systems and an analysis of an actual building renovation project at a municipal hospital in Aarhus, Denmark. The findings indicate a notable absence of criteria and sub-criteria pertaining to the protection of tangible and intangible values in the application of the GBC-DK system. It is justified that in order to improve the sustainability of historic buildings in Denmark, a broader and more in-depth study on the adaptation of the GBC-DK system for historic buildings is needed.