Osborn served as the structural and MEP engineer working with Domokur Architects on renovations to the Tappan Marina in the Muskingum Watershed Conservancy District. The marina is a two-story building that houses a restaurant on the upper level and client offices, retail space, and maintenance staff areas on the lower level. Structural design incorporated the addition of a porch area along the lake side of the building, the addition of an elevator, and the creation of an attic space over the existing roof. The mechanical and plumbing design included a geothermal heat pump system using the lake for renewable energy utilized in the HVAC and domestic hot water systems. Electrical design involved a utility service upgrade and a new generator for emergency and stand-by power.