This study sought to collect data from teens and librarians about their preferences and recommendations for the effective design of physical library spaces for teens. Librarians and teens at twenty-two U.S. public libraries filmed narrated video tours of their young adult (YA) public library spaces. The researchers used qualitative content analysis techniques to analyze the video data and to develop a framework for guiding the design of effective YA public library spaces. In addition to providing specific recommendations for user-centered YA library space design, this study highlights the need for continued user input into the design and maintenance of YA public library spaces as teens' needs evolve and vary across time and from community to community.