Sustaining change beyond individual teachers is challenging and understanding factors making educational change effective is needed. We aimed to identify the factors that educators and construction specialists considered influential to educational change of a general upper-secondary school that was under construction and was to meet the pedagogical goals of the concurrently renewed national core curriculum and legislation. The analysis of multidisciplinary interviews (n = 22) conducted during the early phase of the construction process assisted in identifying the factors that the participants perceived as strengthening and hindering educational change. The strengthening factors related to leadership support, collaboration opportunities, and teachers' professional training, engagement, and transformative agency. The hindrances were constraints that related, for instance, to issues in funding, large group sizes and those that lacked applicable cross-curricular examples. We postulate the need to assist schools and individual teachers in creating conditions for educational change at all levels of municipal education.