The City of San Mateo has policies in the General Plan that support historic preservation, a Historic Resources Ordinance that identifies the process for modifying historic resources, and has also established a local historic resource inventory, which is largely based on the Historic Building Survey completed in 1989. Consistency with these requirements is reviewed in the planning application process in order to ensure that projects will not adversely affect a historic resource’s character and integrity.

The requirements below apply to projects requiring a planning application. The following general information is intended for applicants and property owners when submitting development applications for sites that may be listed or eligible as historic resources.

Historic Resources Evaluations for CEQA

A Historic Resources Evaluation (HRE) by the City’s architectural historian is required when a planning application for substantial demolition (50% or more of exterior walls) is submitted for a property that is more than 50 years old and has not been surveyed previously. This report makes findings and a recommendation whether the property qualifies as a historic resource under the California Environmental Quality Act (CEQA). This process allows the City to identify historic resources that may be eligible for listing and assess the project’s impacts to the resource’s historic integrity. A Secretary of the Interior’s Standards Review by the City’s architectural historian may also be required for planning applications involving exterior alterations to a known historic resource (identified through a prior HRE or in the City’s 1989 Historic Building Survey). The 1989 Historic Building survey recognized approximately 200 significant buildings, including contributors to two historic districts.

CEQA covers many areas of the environment, including impacts to historic districts (either listed in or eligible for the National Register or California Register). CEQA review is triggered by projects that require planning applications. If a project proposes alterations, demolitions, and new construction in a historic district, the CEQA review process may require an independent architectural historian to analyze the project’s potential impacts to that district. Projects that meet the Secretary’s Standards typically will have a less than significant impact to historic districts and may be exempt from CEQA. More impactful projects may require an environmental document to be prepared, such as an Initial Study or an Environmental Impact Report. Note that CEQA does not necessarily prevent impacts to historic districts, but instead it requires the City and the public to be aware of the impacts to determine whether a project should be approved. 

Historic Preservation Ordinance 

The City’s Historic Preservation Ordinance applies to all buildings in the City that are individually eligible for or listed in the National Register, as well as contributors to the Downtown Historic District. Proposals to modify the exterior or construct an addition to any of these resources requires a planning application. These types of projects must also be reviewed by an independent architectural historian to ensure the project meets the Secretary of the Interior’s Standards.

General Plan Community Design Element

The City’s Community Design and Historic Resources Element (CD) of General Plan 2040 sets the policy framework for San Mateo’s physical form, which is shaped first by nature and then by human factors. Applicable Community Design Element policies and actions include policies CD 5.1 through CD 5.13. The Community Design and Historic Resources Element as well as the full General Plan can be found at www.strivesanmateo.org.

Things to Consider

• Can a lot split or duplex development under Senate Bill (SB) 9 occur on a historic resource property?
  No, Senate Bill (SB) 9, does not apply to historic properties or districts.
• Can I make exterior and/or interior alterations to a historic resource?
  Yes, exterior alterations to a historic resource are allowed but may require a planning application and a review by the City’s architectural historian to evaluate consistency with Secretary of Interior Standards, local design standards, and ensure the project does not cause a substantial adverse change in the significance of the historical resource. In addition, exterior alterations may require a building permit following the planning application and HRE. Generally, interior alterations to a historic resource are not subject to a planning application or architectural historian review, and may only require a building permit.
• Can an accessory dwelling unit (ADU) be created within historic districts or on eligible or listed historic properties? 
  Yes, ADUs are allowable, but local governments are allowed to impose design standards that prevent adverse impacts on the resource.