The purpose of the study was to (a) determine the design features of the physical learning environment that support collaborative, project-based learning, and (b) to gain an understanding of the rationale for the selection of the features. The literature review indicated a need for changing learning expectations to prepare learners for rapidly changing roles and responsibilities for the 21st century. Collaborative, project-based learning was identified as a pedagogy that prepares learners for these new learning expectations. Data were collected in three phases using a phenomenological approach. Collection methods included site visits, observations, reflection, text, interviews, and designs. Architects and educators participated in the study. Thirty-two design features were identified and placed into six categories. Upon further reflection and analysis, it appears the essence of the findings is the interrelationship among spaces and people. (Contains 2 tables and 6 figures.)