Cambridge planners unveil zoning proposals for Mass. Ave. and Cambridge Street, with bonuses for active ground floors

Cambridge Planning Board members heard a presentation July 22 from city planning staff proposing new zoning districts for Massachusetts Avenue (Mass Ave) and Cambridge Street that would allow taller residential buildings in exchange for active ground-floor uses, design standards and public benefits in parts of the corridors.

The proposals, presented by Drew Cain, senior city planner, and summarized by Jeff Roberts, director of zoning and development, would create corridor-specific districts that keep current nonresidential density limits while permitting greater residential height where projects provide active uses at street level and meet design standards. "These are places that serve kind of the everyday needs of the neighborhoods," Cain said, describing both corridors as neighborhood main streets that the plan seeks to preserve and reinforce.

City staff landed on a set of shared recommendations for both corridors: retain a base floor-area ratio (FAR) for nonresidential uses, allow greater heights for housing, tie additional height to broadly defined "active" ground-floor uses (including retail, community spaces and smaller offices), and implement minimum building-design standards—such as first-floor height and facade transparency—to support a continuous, walkable street wall.

Under the proposal for Mass Ave, the base residential standard would allow roughly eight stories (about a 1:1 ratio of street wall…