How Do I Write a Sustainable Concrete Specification? – Concrete is used in nearly every structure we build today, including buildings, bridges, homes and infrastructure. With greater emphasis placed on sustainability, design professionals are faced with the challenge of meeting traditional design criteria with evolving criteria that support green building and efforts to reduce impact on climate change. Performance-based specifications for concrete represent an important synergy with sustainability initiatives because they provide the opportunity to optimize mixtures for performance that can also reduce environmental impacts. Prescriptive specifications often adversely impact the environmental footprint of concrete structures. This presentation outlines how concrete performance can be improved while lowering environmental footprint by implementing performance-based specifications.