We analyze the collective sense-making activity of the teaching staff regarding key facets of the start-up process. While the teachers received a variety of supports, including time and resources for collaborating, there was a lack of specific support for the conceptualization and creation of multi-disciplinary, STEM-focused projects. The risk-taking and collaborative actions of the teachers led to three specific instructional approaches that were continuously adjusted to respond to the evolving vision of the STEM-focused school. The teachers also solicited the needs and interests of their students and utilized these in curricular design and instruction, which promoted student buy-in and participation. By the end of the school year, a common vision for STEM-focused, project-based learning was emerging, but not solidified.