Background: Incorporating environmental sustainability (ES) into engineering education is vital to both individual engineering students' success and to the profession as a whole. This study explores attitudes, conceptions, and misconceptions about ES that students bring to the classroom. A promising framework of design-based research is applied to gauge how instructional innovation can impact student attitudes, conceptions, and misconceptions. Purpose: Two questions guided this research: What knowledge and attitudes about ES, particularly those pertaining to engineering, do first-year engineering students have? How can an engineering module focused on life cycle assessment in a first-year engineering course affect students' conceptual understanding to prepare them to develop a robust appreciation of environmental issues and ES in engineering? Design/Method: A quantitative research design in the context of a comparative design-based research study was utilized to examine first-year engineering students' environmental awareness coming into the program and changes in their conceptions of ES following their participation in a module that focused on life cycle assessment (LCA). Results/Conclusion: Following the participation in the LCA module, the intervention was able to address certain misconceptions and support students' shift to deeper understanding about ES. Students' perceptions regarding the complexity of LCA did not change. Including multifaceted issues such as LCA in the teaching of engineering students seems beneficial.