Planning Board recommends zoning changes on Massachusetts Avenue to allow up to 12‑story housing, 18 in Porter Square under PUD

CAMBRIDGE, Mass. — The Cambridge Planning Board voted 7–0 on Oct. 21 to recommend that the City Council adopt a zoning petition that would create three new base zoning districts along the Massachusetts Avenue corridor, allow taller residential buildings where projects provide active ground‑floor uses and meet urban design standards, and create a Porter Square PUD overlay permitting up to 18 stories under a special permit.

City staff said the petition is intended to implement the 2025 Mass Ave planning study. “This petition will most importantly implement the recommendations of the Mass Ave planning study,” Evan Spatrini, senior manager for zoning and development, told the board during the public hearing.

The petition would replace existing business districts that front the corridor with new Mass‑6, Mass‑12 and Mass‑18 (PUD) districts. Under the proposal, residential projects that include active nonresidential ground‑floor uses on the primary street could rise to 12 stories in the primary Mass‑12 district; residential‑only projects would be limited to 8 stories. In Porter Square, the PUD overlay would permit up to 18 stories for projects that meet PUD standards, including a minimum retail FAR of 0.5, a requirement for a grocery store, and at least 20% of lot area designated as public or publicly beneficial open space.

Why it matters: staff and the board framed the petition…