Sunny Du focuses on net-zero building design and deep decarbonization within Thornton Tomasetti’s Sustainability & Resilience practice. She specializes in HVAC design optimization, building energy modeling, and integrated sustainability strategies for high-performance buildings. Sunny works with architects, engineers, and building owners to develop practical, low-carbon solutions that support net-zero readiness, electrification, and compliance with evolving energy codes. Her project experience spans K–12 schools, higher education facilities, and government, healthcare, residential, and community buildings. She advises clients on energy codes and stretch codes and supports incentive programs and certifications. She also coordinates mass timber and photovoltaic strategies to help clients meet ambitious carbon, resilience, and wellness goals. Sunny mentors teams and advances energy analysis workflows, helping project teams deliver consistent, high-quality decarbonization and sustainability outcomes.