McLennan is the creator of the Living Building Challenge, as well as a primary author of the WELL Building Standard. He serves as the Chairman of the International Living Future Institute and is the CEO of McLennan Design, his own architectural and planning practice.

He is the recipient of the prestigious Buckminster Fuller Prize, has been called a “World Changer” by GreenBiz magazine, and has been selected as the Award of Excellence winner for Engineering News Record. He is the author of 6 books, including the Philosophy of Sustainable Design, which is considered the ‘bible for green building,’ and is both an Ashoka Fellow and Senior Fellow of the Design Future’s Council. He has been selected by Yes! Magazine as one of ‘15 people shaping the world.’  McLennan’s work has been published in dozens of journals, magazines, and newspapers around the world.