Several properties in the Merchant City are not qualified as listed buildings but are designated shortly after restoration. This controversial phenomenon reflects legislation issues of listed buildings on the one hand and restoration issues with built heritage on the other. An investigation incorporating the review of existing preservation policies, archival research, and detailed case studies, complemented by on-site inspections, has led to the identification of a key concept: 'Group Value.' Researchers notice the growing limitation of the listed system or preservation policies, yet few have analyzed this phenomenon in specific cases with historical context.

This paper will elaborate on the formation of the concept of ‘group value’ and provide a theoretical lens for understanding the crisis and opportunities of ‘group value’ in the adaptation of historic buildings.