This study investigates agency-structure dynamics in students and teachers' social activity in a novel design and making environment in the context of the Finnish school system, which has recently undergone major curricular reform. Understanding that agency is an important mediator of educational change, we ask the following questions: How are agency-structure dynamics manifested in the social activity of students and their teachers in a novel design and making environment? How do agency-structure dynamics create possibilities and obstacles for educational change? The data comprise 65 hours of video recordings and field notes of the social activity of students aged 9-12 years old (N = 94) and their teachers collected over a period of one semester. Our study shows how the introduction of the novel learning environment created a boundary space in which traditional teacher-centered activity patterns interacted and came into tension with student-centered modes of teaching and learning. Our study reveals three distinctive agency-structure dynamics that illuminate how the agentive actions of both teachers and students stabilized existing teacher-centered practices and, at other, times ruptured and broke away from existing patterns, thus giving rise to possibilities for educational change.