This project was funded and sponsored by 晴美建設 for the renovation of an aging five-story building, transforming it into a German-style energy-efficient and comfortable building. The renovation upgraded the property from a purely residential use to a mixed-use commercial space. The scope of work included the installation of an external thermal insulation system, airtightness detailing, and a heat recovery ventilation system, injecting new life into the old building and significantly extending its service life. Relevant energy-efficiency technical data have been uploaded to the Passive House Database of the Passive House Institute (PHI).