Marsh serves as Assistant Director for the Conn Center for Renewable Energy Research at the University of Louisville. In 2012 -13, he supported a team of engineering and architecture students as they designed and built the Phoenix House for the 2013 Department of Energy Solar Decathlon competition. After the competition in fall of 2013, Marsh coordinated the siting of the house on UofL's campus and oversaw its conversion into the Conn Center's administrative offices and residential scale in situ laboratory, which opened in spring of 2016.
As part of the installation of the Phoenix House, Marsh created an outdoor laboratory and sculpture garden from massive pieces of discarded concrete roadway as well as local felled walnut, maple, and ash, which had been devastated by the emerald ash borer. He created unique seating, workbenches, and hardscape around the exterior of the house and installed 3 of his carved wood and cast iron sculptures.
The site is a common gathering area for faculty, staff, and students. The installation showcases sustainability and features demonstrations on various renewable energy concepts, including residential solar and energy storage, smart metering, and the industrial hemp and kenaf energy crops.