Planning board approves special permit to convert 350 Massachusetts Ave. to lab with ground-floor retail; board conditions design review

The Cambridge Planning Board voted May 20 to grant a project-review special permit for 350 Massachusetts Ave., a five‑story office building that Biomed Realty will renovate and convert to lab space with ground-floor retail.

Biomed Realty representative Ashley Maslinski described the proposal as a reuse of a mostly vacant 1998 office building to “revitalize the ground floor space” and improve the pedestrian experience on Massachusetts Avenue. The application requests conversion to roughly 100,000 square feet of lab use with about 4,000 square feet of retail at grade; no additional vehicle parking is proposed and the project includes 30 new bicycle parking spaces.

Why the project needed a special permit

City staff explained that a change of use above 50,000 square feet in the Cambridge Port Revitalization Development District triggers the Planning Board’s project-review special-permit requirement. The project team said the design preserves most of the existing structure and brick, targets a LEED-equivalent green building approach, and aims to reduce embodied carbon by reusing the building envelope rather than constructing a new building.

Key design and operations elements discussed at the hearing

- Ground-floor activation: the applicant proposed deeper arched openings, movable glazing and multiple retail entrances on Mass. Ave. and Blanche Street to encourage retail variety and spill‑out activity. Developer and architect emphasized flexibility for future retail tenants. Ashley Maslinski said the plan would add “new retail along Massachusetts Avenue, as well as redesigning the lobby and making the pedestrian experience that much more friendly.” - Flood resiliency: the parcel lies within flood-risk contours; the team described designs that protect critical infrastructure with a concrete ring wall, raise vulnerable interior areas and route expected floodwater into recoverable spaces. The team showed a 10‑year and a 100‑year flood-event strategy for protecting building systems. - Mechanical penthouse and roofscape screening: the design places taller mechanical equipment away from Massachusetts Avenue and Sydney Street and uses cornice elements and a stepped screen to reduce visible massing; staff and board emphasized continued attention to sight lines and screening. - Loading, deliveries and outdoor activity: the project retains two loading bays; board members and the project team discussed truck turning radii and operations, concluding that deliveries typically occur outside dining hours and can be managed operationally. The team proposed using Blanche Street for flexible, temporary outdoor activation and event programming while recognizing its service function. - Sustainability and electrification: the applicant said it would achieve a 25 percent electrification level at occupancy (primarily via air-source heat pumps covering the bulk of heating needs) with the ability to move toward full electrification over the building’s life. The project team said it would meet Cambridge Article 22 green-building requirements and expected a substantial embodied-carbon reduction versus new construction.

Public testimony and community support

Speakers from the Central Square Business Improvement District, local artists and several nonprofit and community groups spoke in support of the redevelopment, highlighting Biomed Realty’s prior event partnerships, community programming, and the potential for new retail and artist space. Michael Monastine, president of the Central Square BID, said he was “calling in tonight to express my strong support for the proposal to repurpose 350 Mass Ave.” Several community organizations advocated for local retail opportunities and art activation.

Board findings and vote

Board member Mary Liedecker moved to grant the requested project-review special permit; Diego Macias seconded. Before voting, the board discussed outstanding design refinements staff should track — including roof screening, flood-resilient first-floor details, bike-room transparency and art-box curation, activation and temporary seating strategies on Blanche Street, and additional street-tree/streetscape work with city departments.

The board made the required findings for a project-review special permit and approved the permit on a 7–0 roll-call vote (Ted Cohen, Mary Liedecker, Diego Macias, Ashley Tan, Carolyn Zurn, Joy Jackson, and Tom Sanovich voting yes). The board’s approval includes continued coordination with CDD, DPW, Transportation, and the city’s sustainability reviewers to finalize details and the applicant’s commitment to the described flood‑resiliency and electrification approach.

Next steps

The project will proceed to final permitting and design review with staff to resolve the remaining streetscape, mechanical-screening and operations details described during the hearing. The developer said it expects the reuse to boost activation in University Park and Central Square and cited existing community partnerships such as festival activations and artists’ studios used in the building.