That the City Manager be and hereby is requested to work with the relevant departments, including Community Development and Law to review the attached proposed amendment language and propose any adjustments no later than the October 2, 2023 Regular City Council Meeting

Councillor Quinton Zondervan Solar RequirementGreen Roofs Amendment September 11, 2023 (with Attachment A) Whereas: The City Council adopted the Green Roofs Zoning Ordinance in June of 2021 which requires certain new construction buildings to install a Green Roof or Solar Energy System; Whereas: Technology and economic improvements make it feasible to require solar installations in areas that were rightfully excluded from the Green Roofs requirement, including parking decks, rooftop HVAC equipment and access pathways on the roof, through the use of solar canopies; Whereas: The ongoing and worsening global climate crisis that continues to deliver unprecedented catastrophes on an almost daily basis compels us to maximally leverage the urban spaces available for renewable energy production, in Cambridge primarily through the deployment of Solar Energy Systems; Whereas: The City Council would like to propose appropriate amendments to the Green Roofs Zoning Ordinance to maximize the solar energy potential of new construction in Cambridge; therefore be it Ordered: That the City Manager be and hereby is requested to work with the relevant departments, including Community Development and Law to review the attached proposed amendment language and propose any adjustments no later than the October 2nd, 2023 Regular City Council Meeting Please see attached additional text

ATTACHMENT A 22.30 - GREEN ROOFS 22.31 Purpose. The purpose of this Section is to remove potential impediments to the development of green roof systems on new and existing buildings by clarifying that such systems should not count against a building's Gross Floor Area, and by providing for limited access and enjoyment of green roofs by occupants of a building, and to require new buildings of substantial size to include vegetation and/or solar energy roofing systems on much or most of the available roof area. 22.32 Green Roof Area as defined in Article 2.000 of this Zoning Ordinance may be accessible by means of a roof entrance. 22.33 Floor Area Exemptions for Green Roof Area. 22.33.1 Spaces meeting the definition of Green Roof Area, which are to be accessed only for maintenance purposes and are not intended to be used by building occupants or others, shall be exempt from the calculation of Gross Floor Area of a building. 22.33.2 Spaces meeting the definition of Green Roof Area, which are intended to be accessed for use by occupants of the building or others, and which are located above the third floor of the building, may be exempted from the calculation of Gross Floor Area of a building only after the granting of a special permit by the Planning Board. The proponent seeking such a special permit must demonstrate that the Green Roof Area is designed such that the vegetation will withstand the foot traffic associated with its anticipated use. The Planning Board shall also consider the potential visual, noise and privacy impacts of the anticipated use on neighbors. Unless such a special permit is granted, any Green Roof Area located above the third floor of a building that is intended to be accessed for use by building occupants or others shall be counted as Gross Floor Area. 22.34 Floor Area Exemptions for Patios or Decks Adjacent to Green Roof Area. 22.34.1 In non-residential zoning districts and in Residence C-1A, C-2, C-2A, C-2B, C-3, C-3A, and C- 3B zoning districts, where a rooftop surface above the third floor includes Green Roof Area, adjacent open-air outdoor space intended for use by building occupants or other persons that does not meet the definition of Green Roof Area, such as a patio or deck, shall be exempted from the calculation of Gross Floor Area of the building, provided that the total space exempted in such a manner shall not exceed fifteen percent (15%) of the amount of Green Roof Area on the building and that all such usable outdoor space shall be set back at least ten (10) feet from all outer roof edges. 22.34.2 In residential zoning districts not listed in Section 22.34.1 above, where a rooftop surface above the third floor includes Green Roof Area, adjacent open-air outdoor space intended for use by building occupants or other persons that does not meet the definition of Green Roof Area, such as a patio or deck, may be exempted from the calculation of Gross Floor Area of the building only after the granting of a special permit by the Planning Board. The total space exempted in such a manner shall not exceed fifteen percent (15%) of the amount of Green Roof Area on the building and all such usable outdoor space shall be set back at least ten (10) feet from all outer roof edges. In granting the special permit,

the Planning Board shall consider the location and orientation of the patio or deck in relation to adjacent properties and potential visual, noise and privacy impacts of the anticipated use on abutters. 22.35 Green Roofs Requirement. 22.35.1 Applicability. This Section 22.35, et. seq., shall apply to any new building or structure of twenty- five thousand (25,000) gross square feet or more, except it shall not apply to affordable housing buildings that either are developed under the Affordable Housing Overlay (AHO) as defined in Section 11.207 or have a majority of their units permanently reserved for households at or below 100% of AMI. 22.35.2 Requirement. (a) At least 80% of the roof area of the building as measured in plan view, excluding those portions of the roof listed below, shall be devoted to Green Roof Area, Biosolar Green Roof Area, or Solar Energy Systems. 1. Areas having a slope greater than 3 in 12 or twenty-five percent (25%). 2. Areas designed and managed for use by building occupants or the general public. 3. Vehicular parking decks. 4. Chimneys, water towers, air conditioning equipment, elevator bulkheads, skylights, ventilators and other necessary features appurtenant to buildings which are usually carried above roofs and are not used for human occupancy, in addition to conduit, visual and acoustical screening, access routes for maintenance and service, and other areas that must be clear of obstruction to comply with applicable building and safety codes. (b) In the case of non-residential or mixed-use buildings in which at least half of the Gross Floor Area is devoted to one or more of the non-residential uses listed below (with reference to the Table of UseRegulations, Section 4.30 of this Zoning Ordinance), excluding any municipal buildings, at least 80% of the roof area of the building as measured in plan view, excluding those portions of the roof listed above, shall be devoted to Green Roof Area or Biosolar Green Roof Area: 1. Transportation, Communication & Utility Uses (Section 4.32); 2. Educational Purposes (Section 4.33-b.); 3. Noncommercial Research Facilities (Section 4.33-c.); 4. Other Institutional Uses (Section 4.33-h.); 5. Office and Laboratory Use (Section 4.34); 6. Retail Business and Consumer Service Establishments (Section 4.35); 7. Open Air or Drive In Retail & Service (Section 4.36); 8. Light Industry, Wholesale Business and Storage (Section 4.37); or 9. Heavy Industry (Section 4.38). (c) In addition to the above, any remaining portions of the roof, up to 80% of the roof area of the building as measured in plan view, including individual portions greater than 500 square feet in size, not devoted to Green Roof or Biosolar Green Roof, including portions exempted in 22.35.2(a) above, shall be devoted to Solar Energy Systems, including via the construction of a solar canopy, unless an Exemption is granted via special permit by the Planning Board for the following reasons:

1. The area is shaded from the sun and therefore unsuitable for Solar Energy production. If the Planning Board determines that the area could reasonably become available for Solar Energy production in the future (because e.g. a shading structure is scheduled for removal), the area must be wired for Solar Energy Systems and installation of such a System shall commence within one year from the time that the obstacles are removed. 2. The Electric Utility is unable to provide an interconnect, in which case the area must be wired for Solar Energy Systems and installation of such a System shall commence within one year from the date that the Electric Utility announces the availability of an interconnect. 3. The Solar Energy System will be owned and operated by a third party (e.g. Community Solar), in which case the roof area must be wired for Solar Energy Systems, and installation of such a System shall commence no later than one year from the issuance of the Certificate of Occupancy. 22.35.3 Exemption. The Planning Board may grant a special permit to reduce the required Green Roof Area, Biosolar Green Roof Area, or Solar Energy System below the area required by Section 22.35.2, provided that each square foot so reduced be compensated by a unit price contribution to the Cambridge Affordable Housing Trust. This unit price shall be determined based on the average costs to design, install, and maintain green roofs and rooftop solar energy systems in Cambridge using actual cost figures to the extent possible, shall be subject to annual adjustment based on standard construction cost indices, and shall be calculated, and recalculated approximately every three years, by the Cambridge Community Development Department. All such funds contributed to the Trust shall be dedicated to the design and incorporation of Green Roof Area, Biosolar Green Roof Area, or Solar Energy Systems into new or existing affordable housing developments. 22.35.4 Effective Date. The provisions of this Section 22.35, as adopted on June 1, 2021, shall not apply to structures lawfully in existence or lawfully begun before June 1, 2021, or to a building or special permit issued before June 1, 2021, and shall take effect on June 1, 2021.