In response to societal shifts, K-12 teachers are struggling to design effective learning environments. The advent of increased access to world-linking technology has extended the use of distance education to enrich and expand the learning landscape for students. A number of individuals have suggested that a body of learning theory, constructivism, supports technology-rich classrooms as a part of a vision of the twenty-first century. To support and facilitate teachers' responses to these changes in their classrooms, this project sought to identify a core of constructivist-based learning environment designs, experiences, or elements necessary for their implementation in a distance education setting. A panel of knowledgeable individuals in the areas of constructivism and technologically-mediated education participated in an electronic Delphi study. Findings indicated that teachers who wish to develop constructivist-based distance learning environments need training in the creation of authentic, student-centered lessons. (Contains 5 tables.)