With so much talk about energy efficiency in buildings people have somehow lost track of what comes before or after a single measurement. When actually looking at long term sustainability the existing materials matter, and considering these changes a view on what is the most sustainable approaches to ensure our build environment matches our sustainability goals. Jennifer O’Connor is the President of the Athena Sustainable materials Institute. She has been working in construction-sector sustainability since 1983, with diverse multidisciplinary roles in research, design, analysis, and education in Canada and the U.S. Her work experience has an emphasis on energy efficiency, sustainable design, and overall building performance, and her background in both architecture and HVAC engineering provides a strong technical foundation in many building systems. She has been President of the Athena Institute since 2011. This talk was given at a TEDx event using the TED conference format but independently organized by a local community. Learn more at https://www.ted.com/tedx