As global climate targets push the built environment toward decarbonization, achieving net-zero energy (NZE) and whole-life carbon neutrality has become a crucial design objective. While the architecture and construction industries have made strides in operational efficiency, embodied carbon and lifecycle impacts remain complex challenges. Without accessible models and clear processes, NZE ambitions often face obstacles during early design phases. This research investigates the requirements for achieving NZE across a project’s entire carbon profile — from initial concept through construction and operation. By analyzing eight Gensler projects with diverse typologies, contexts, and carbon goals, we identified key success factors, recurring decision points, and implementation challenges. The resulting insights go beyond technical checklists to reveal the human, financial, and storytelling dynamics that shape whether a project succeeds. More than a roadmap to compliance, it is a call to rethink how teams embed carbon reduction goals into project DNA — starting from day one.