Old city, like Tainan in Taiwan, actively seeking renewal to prevent decay. The ideas of “Creative City”, is to identify, attract and sustain talent so it is able to mobilize ideas, talents and creative organizations. The built environment and the setting—is crucial for establishing the milieu. However, housing and offices are expensive for young people want to start a creative profession. This design propose a new solution to transform the usually messy, unintegrated rooftop structure and billboard to a “Co-sharing Startup Hub” for young generation.