A communication transmitted from Louis A. DePasquale, City Manager, relative to a Planning Board recommendation on the Green Roofs Ordinance (Oliver, et al.) Zoning Petition

CITY OF CAMBRIDGE, MASSACHUSETTS P L A N N I N G B O A R D CITY HALL ANNEX, 344 BROADWAY, CAMBRIDGE, MA 02139 Page 1 of 2 Date: March 2, 2021 Subject: Green Roofs Ordinance (Oliver, et al.) Zoning Petition Recommendation: The Planning Board does NOT RECOMMEND adoption. To the Honorable, the City Council, On February 10, 2021, the Planning Board (the “Board”) held a public hearing to discuss the Green Roofs Ordinance (Oliver, et al.) Zoning Petition (the “Petition”). Representatives of Mothers Out Front, a climate advocacy group, presented the Petition at the hearing. Staff from the City’s Community Development Department and Department of Public Works also attended the hearing and answered questions from the Board. The proposed revisions to Section 20.30 of the Zoning Ordinance would require new construction and “significant rehabs” of buildings with 20,000 square feet or more to install green roof systems. These systems could be vegetative or a combination of vegetative and solar energy systems, referred to as “BioSolar.” The petition stipulates that the green roof system must cover 100% of the roof, with exceptions for “appropriate vegetated free zones and roof gravel,” parking, and some mechanical equipment. If this standard cannot be met, the petition proposes that a payment must be made to a city-controlled “Green Roofs fund” that would be used to provide grants to property owners for the creation of green roofs on existing buildings. The petition proposes adding definitions for “Green Roof,” “Functional Green Roof,” and “BioSolar Roof” to Article 2.000 Definitions. Following a presentation by the Petitioners, Board members posed a number of questions to the Petitioners and City staff and discussed the merits of the Petition. The following is a summary of comments made by Board members: • All members of the Board expressed support for encouraging the construction of green roofs in Cambridge and believe that the climate crisis demands urgent action; several members also remarked on the importance of Mothers Out Front’s work and commended the group for their organization and advocacy on this issue. • Board members raised many concerns regarding the clarity of the proposed language, noting that it is not clear how the zoning would apply under different circumstances nor does it provide appropriate guidance to a property owner or designer to understand how to comply with the requirement. Some terms are not clearly defined and it is not clear how some provisions would interact with current provisions in the Zoning Ordinance, such as provisions related to Functional Green Roof Area and Gross Floor Area. The Board noted that there are several general statements about the benefits of green roofs

City of Cambridge, MA • Planning Board Report Green Roofs Ordinance (Oliver, et al.) Zoning Petition March 2, 2021 Page 2 of 2 that are confusing in the context of zoning requirements. The “payment-in-lieu” provisions are also unclear. In its current state, the text could require significant changes that may legally require refiling and new public hearings prior to adoption. • Several Board members raised concerns about the practicality of green roofs in all circumstances, including buildings with sloped roofs and the rehabilitation of existing structures. Board members also raised concerns about how the proposed requirements would interact with code requirements related to safety, accessibility, and building mechanical systems. • Board members raised concerns that there did not appear to be much input from entities that would be most directly affected by the proposed zoning, such as property owners, developers, designers, and engineers. They expressed interest in hearing more from those who would be responsible for complying with the requirements if they were adopted. • Board members recognized the ongoing work of the City’s Climate Resilience Zoning Task Force (“Task Force”) that was appointed to make recommendations on zoning changes related to climate change resilience and adaptation. Board members noted that the City is trying to accomplish multiple environmental objectives and that the Task Force is the appropriate venue for stakeholders to have conversations about benefits and trade-offs. Board members see green roofs as one of many strategies to manage the climate crisis and appreciate the comprehensive approach that the Task Force is taking. • Some Board members were generally comfortable with a prescriptive approach to requiring green roofs; however, many others expressed preference for an approach that provided property owners and developers with different choices for meeting the City’s environmental objectives, rather than mandating only one approach. Some Board members gave the “Cool Factor” approach being contemplated by the Task Force as an example of the type of flexible requirement that they would prefer. • Board members questioned whether 20,000 square feet was an appropriate threshold given that the threshold for Green Building Review and other special development standards is set at 25,000 square feet or more. • Board members raised concerns about the impact on affordable housing developments, given the unique financial circumstances of such developments, and questioned whether such projects should have an exemption from these requirements. Following deliberation, the Board voted to recommend that City Council not adopt this Petition, with eight members voting in favor and one opposed. All nine Board members voted in favor of forwarding this summary of Board members’ comments to the City Council. Respectfully submitted for the Planning Board, Catherine Preston Connolly, Chair.