The idea of increasing density in a neighborhood is frequently an off-putting concept for residents, but Dan Parolek has a solution: the "missing middle." He coined the term in 2010 to identify a range of housing types that provide more dwelling units than a single-family home but fewer than a midrise apartment building. These missing middle housing types—duplexes, fourplexes, cottage courts, and more—increase density while still keeping with the scale and character of a neighborhood. His firm, Opticos Design, helps communities implement form-based coding to allow for these structures.

Dan shares the firm's ideas and work with host Courtney Kashima, AICP, including a project in South Bend, Indiana, that tackles the issue of one neighborhood's 500 vacant lots and how to build on them. He stresses the need for a foundation of physical design within planning—without turning planners into designers. Courtney and Dan also explore his career path: He started as an architect but quickly realized he wanted to earn a graduate degree in urban design. After being told by several firms that he needed to choose one discipline or the other, he founded Opticos—a creative maneuver that allowed him the freedom to work on his dual passions.