The relationship between architect and engineer has evolved as sustainable design has gained importance. The design process between the team is less hierarchical and much more collaborative. Beyond the team’s reliance on engineers for technical expertise, they must also have a broader understanding of a project’s goals, as their input has a much greater impact than before. Today, the process of engineer more closely reflects the process of architecture, each relying on the other. Understanding the importance of integrating HVAC design and building envelope strategies into the early stages of the design process creates a synergy within architecture and engineering.