Holly Lennihan

Director of Sustainable Design | Hickok Cole Architects

Holly Lennihan


Holly serves as Director of Sustainable Design for Hickok Cole Architects' high-performance building practice. Currently, she is spearheading the completion of the American Geophysical Union’s Headquarters renovation, the largest existing building net zero energy retrofit on the east coast. She is a member of ULI Washington’s Sustainability Committee, the Tysons Partnership Sustainability Council, the Net Zero Energy Coalition of the National Capital Region and the USGBC NCR Chapter’s Women in Green.

Under Holly’s leadership, the team has won a series of state and federal grants focused on sustainability, resilience and urban ecological systems. The Sustainable Design practice has also provided consultation services to the District of Columbia’s Department of Energy and the Environment including, a budget analysis for sustainable infrastructure construction, a masterplan for the Kingman and Heritage Island Park, and creating a Sustainability Guide for Existing and Historic Properties. Holly and her team were awarded a United States Forest Service Wood Innovation Grant to design the Kingman Island Ranger Station out of cross laminated timber, resulting in a more comprehensive understanding of how to incorporate mass timber into the firm’s holistic design offerings.

Over the course of her design career, Holly has worked on repositioning of existing office buildings, historic preservation and adaptive reuse projects, corporate interiors, multifamily housing, educational facilities, and master planning studies. For over 20 years, she served on the board of Mi Casa, a DC-based nonprofit housing developer whose expertise includes representing tenants in the TOPA process, applying LIHTC financing, and creating affordable rental properties while maintaining those in existence.

Holly graduate magna cum laude with a Bachelor of Fine Arts from Harvard University and a Master’s of Architecture from Harvard’s Graduate School of Design.