The progression from novice to expert may involve logical hierarchies and increased structural complexity in the manner in which students develop an understanding of concepts. Appreciating students’ prior knowledge can facilitate this progression and inform what and how academics teach students about sustainability and equip them to influence sustainable construction in Ghana. This research, therefore, investigates the conception and structural variation of MSC construction students’ prior knowledge of sustainability. The study explores the relationship between previous education in sustainability, work experience as well as age, and the level of structural complexity of students’ conception of sustainability. Before taking a course in sustainable construction, students’ descriptions of sustainability were collected using questionnaires. The descriptions of sustainability were classified using a structure of learning outcomes (SOLO) based analytical framework. Student descriptions were also scrutinized for themes related to key principles of sustainable development (SD) by Gibson. Results revealed that 78% of respondents indicated that they were aware of sustainability. However, students’ conception of sustainability was narrow with a focus on environmental dimensions (44%). Issues of sustainability related to precaution and adaption as well as immediate and long-term integration are not mentioned at all (0%). The structural complexity of students’ conception of sustainability was lower for their prior knowledge than the summative evaluation (final course assessment). The study highlights the areas of sustainability that need to be emphasised in the course to develop graduates who have a balanced understanding of sustainability. It also recommends the need for further research amongst Ghanaian students at all levels and in all fields to explore understanding within different groups of students.