Located in the heart of Siam Square, Bangkok’s trendiest shopping district, the Siam Square One project reveals the design competition winning proposal that fits the site previously occupied by the Siam Theater. The open-air concept is introduced to retain the original ambiance of the Siam Square shopping streets. The lower 2 levels occupied by small shops are air-conditioned area while the main 7 levels above are open-air. Foot traffic is another key issue of the proposed scheme. A gentle-slope walkway is designed as the main walking street connecting from the platform of the sky train to the street level inside Siam Square. The variety of the circulation routes, the dynamic spaces within the building and the overall architectural language produce the energy and reflects the the diverse characteristics of teenagers, the project’s main target group.