Dennis began his career in building in 1975 because of a passionate interest in solar energy and a desire to use resources more sensibly. Since then, he has become a nationally recognized authority on environmentally friendly building practices. He has spoken before the Policy Advisory Board of the Joint Center for Housing Studies at Harvard University, the national Remodelers Guild, and a variety of community groups on green building issues. His commentaries on sustainable solutions to environmental and social problems have been published locally, regionally, and nationally.

Dennis is active in community organizations: since 1995, he has served as a member of the County of Santa Barbara’s Innovative Building Review Program, which encourages energy efficiency and sustainable practices in building projects within the county. He chairs the Dean’s Council of the Bren Graduate School of Environmental Science and Management at the University of California, Santa Barbara. He founded the Parade of Green Buildings, an annual event for a number of years that exhibited the best local examples of green building to the public. He is currently a board member at the Museum of Natural History and a sustainable champion on their master plan committee.

In addition to his interest in sustainable land use planning, design, and construction, Dennis enjoys foreign languages, wilderness retreats, healthy cooking, and plein air watercolor painting.