David Tilley is an Associate Professor in the Department of Environmental Science and Technology at the University of Maryland. His work focuses on ecological engineering, which he defines as an emerging field that combines natural applied sciences with engineering design. Tilley is particularly interested in how to design, build, and operate new types of ecosystems that connect society with nature to benefit both. He leads the Ecosystem Engineering Design Lab (EEDL), where he researches the effects of various ecological systems, including green walls, green roofs, and artificial wetland gardens. Additionally, Tilley examines energy and water balances, as well as water quality within built environments. His lab investigates the theoretical foundations of dynamic emergy accounting, aiming to establish a framework for environmental accounting that remains independent from neoclassical economic biases.