I-SUSTAIN was started in 2003 while Patricia Chase and Jayson Antonoff were living in Denmark. While Jayson was getting his Masters degree in Renewable and Sustainable Energy Planning, they were impressed not only with Denmark’s advanced energy systems, but also with the public transit system, public spaces, bicycling infrastructure, waste management and more. What started as one professional research mission for public and private decision makers from the Pacific Northwest to Denmark and Sweden has evolved into a company that leads study tours and delegations throughout the world.
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When Patricia started I-SUSTAIN she had no experience in sustainable development. Over the years she has learned from leading practitioners worldwide, including clients willing to push boundaries and explore what is possible - architects, developers, engineers, labor leaders, utility professionals, tribal representatives, elected officials, and public agency staff.
 
I-SUSTAIN is headquartered in Seattle, Washington.