New buildings developed within the Overlay would be subject to the same discretionary review process(es) otherwise required by the IZO (Implementing Zoning Ordinance), and be subject to CEQA (California Environmental Quality Act), as new buildings are under the existing regulations. New buildings not within a historic district would be subject to Major SPAR. New buildings within a historic district would continue to be subject to (1) Historic SPAR (Site Plan and Architectural Review), (2) historic district design guidelines, (3) and the Secretary of the Interior’s Standards. Discretionary review with compliance with these three measures of review would provide for a robust evaluation.
Supporting guidelines and recommendations for the Secretary of the Interior’s Standards, drafted by the Technical Preservation Services, responds to new construction and infill development near historic resources, noting the following:
New construction should be appropriately scaled and located far enough away from the historic building to maintain its character and that of the site and setting. In urban or other built-up areas, new construction that appears as infill within the existing pattern of development can also preserve the historic character of the building, its site, and setting.
The Overlay considered the potential for bulk/mass conflicts that could be created by new buildings adjacent to historic resources, to propose new building setback and stepback controls. These building “setback and stepback” controls are illustrated in Exhibit 4.4 – New Development Adjacent to a Historic Resource. Staff believes that the stepbacks illustrated in Exhibit 4.4, along with the SPAR or Historic SPAR discretionary review process, and environmental review under CEQA, will ensure that new development will not create an impact to adjacent historic resources.
The Historic Commercial District’s National Register of Historic Places registration form described the district’s boundary was developed by identifying areas of distinctly different characters, following contiguous parcel lines, and encompassing nearly all of Petaluma’s pre-1946 commercial buildings. The district originally included 64 elements that contribute to its historic character, 35 that do not contribute, and 14 empty parcels. The district’s integrity is high due to the concentration of resources, the size and importance of the contributors, and the inconspicuousness of non-contributors. This historic district reflects a boundary that encompasses a single area of land containing a significant concentration of buildings for a district supporting visual continuity in the downtown area.
As noted in the previous sections of this staff report, following the June 13 study session, the Overlay boundary was reduced to three Subareas. This reduction in the Overlay boundary responds to public concerns by dramatically reducing the inclusion of properties within historic districts, specifically the Historic Commercial District. As illustrated in Exhibit 2, Subarea A retains three lots and Subarea B retains one lot at the perimeter of the Historic Commercial Historic District. Subarea C is completely outside of a historic district.
Eligible historic resources outside of the historic districts and within these Subareas have not been identified and would be evaluated as part of the discretionary review and CEQA (California Environmental Quality Act) review process. A Historic Cultural Resource Report (HCRR) is being prepared by Diana Painter for additional documentation to evaluate the historic context and provide recommendations for eligible and designated historic resources within and adjacent to the proposed Overlay Subareas, (Scope of work presented at the June 13, 2023, Study Session). A draft of the report is underway and will be presented to the PC, the HCPC, and the public when completed. Project documents for the Overlay are available on the City’s planning project dedicated project webpage.