A small vacant lot nestled among the gray office buildings of Yeouido! We sought to realize a new mixed-use residential complex that embodies a happy life through an eco-friendly “Forest Step”—a concept no one could have imagined. To achieve this, we planned a mixed-use complex comprising Happy Housing, a hotel, officetels, and green living facilities as a strategy to revitalize the area through community engagement, cultural and welfare services, and job creation. We proposed a space where architecture, nature, culture, and people interact, serving as a new-concept urban Happy Housing prototype that embodies the commitment to the evolution of Happy Housing.