MMW Architects in Missoula, Montana, approached investigators at WTI about using an innovative concrete material in a commercial building project to help them achieve the highest feasible LEED rating for their project. The LEED (Leadership in Energy and Environmental Design) rating system, developed by the United States Green Building Council, provides a quantitative measure of a project’s performance relative to human and environmental health. Part of a project’s rating is based on the characteristics of the materials from which it is constructed, with points being awarded for the use of recycled and locally available materials. Surprisingly, an attractive material in this regard may be concrete; notably, concrete made with an alternate binder to traditional Portland cement and recycled aggregates. For this project (a new banking facility in Missoula, MT), the focus is on characterizing the engineering and long term durability performance of a 100% “green” concrete made with recycled crushed glass as the aggregate and a high calcium class C fly ash as the binder. This approach is unique; much of the existing and current research on fly ash in concrete focuses on partial replacement of Portland cement, not 100% replacement.