18-48.010.1 High seismic activity. The City of Santa Rosa is located in an area of high seismic activity between the Healdsburg-Rogers Creek and San Andreas Faults. It has experienced, and will continue to experience, moderate to severe seismic activity in the foreseeable future.
18-48.010.2 Life safety danger. Existing buildings subject to high seismic hazard levels continue to be a serious life safety danger to the people who live and work in, and around, them. The primary goal of seismic retrofit is to improve building performance and life safety during a seismic event. To improve life safety in seismically hazardous buildings, yet keep seismic retrofits economically feasible, the City adopted Resolution 9820 (in 1971) which was later repealed and reenacted in certain parts as set forth in this chapter.
18-48.010.3 Goals. This chapter provides procedures for the systematic evaluation and retrofit of existing buildings within the City of Santa Rosa.
(Ord. 2022-015 § 13)
For the purpose of this chapter, the following words, terms, and phrases shall be defined as follows:
Abatement.
The lessening of potential and/or existing life-safety hazards, in the built environment, to occupants and neighboring uses.
Addition.
An extension or increase in floor area, number of stories, or height of a building or structure.
Alteration.
Any construction or renovation to an existing structure, other than repair or addition.
Authority having jurisdiction.
An organization, political subdivision, office, or individual responsible for administering and enforcing the requirements of a code or standard, or for approving equipment, materials, an installation, or a procedure.
Building.
Any structure utilized or intended for supporting or sheltering any occupancy.
Building element.
A fundamental component of building construction which may or may not be of fireresistance-rated construction and is constructed of materials based on the building type of construction.
Building height.
The vertical distance from grade plane to the average height of the highest roof surface.
Building type.
A building classification defined in Section 3.2.1 (Table 3-1) of ASCE 41-13 that groups buildings with common seismic-force-resisting systems and performance characteristics in past earthquakes.
Evaluation.
A process that critically examines a building and/or building elements for life-safety hazards based on the standards specified and referenced in this chapter. The process involves collecting and analyzing information about the building and/or building element characteristics, and the resulting report stating judgments about deficiencies, hazards, and potential solutions.
Historical significance.
Historical building qualifications for use with the California Historical Building Code (Title 24, Part 8), or with the Santa Rosa City Code.
Level of seismicity.
A degree of expected seismic hazard. For ASCE 41-13, levels are categorized as very low, low, moderate, or high, based on mapped acceleration values and site amplification factors, as defined in Section 2.5 (Table 2-5) of ASCE 41-13.
Light-frame wood construction.
A type of construction whose vertical and horizontal structural elements are primarily formed by a system of repetitive wood framing members.
Occupancy classification (occupancy class).
The formal designation of the primary purpose of the building, structure, or portion thereof, as defined in Chapter 3 of the California Building Code.
Performance level.
A limiting damage state for a building, considering structural and nonstructural components, used in the definition of Performance Objective.
Performance objective.
One or more pairings of a selected Seismic Hazard Level with both an acceptable or desired Structural Performance Level and an acceptable or desired Nonstructural Performance Level.
Permitted.
A building and/or other construction permit is/was issued for the proposed work.
Rehabilitation.
The restoration, re-classification, demolition, and/or abatement of deficient buildings and building elements to a state of acceptable life safety, as determined in accordance with this chapter and other applicable codes and standards.
Repair.
The reconstruction or renewal of any part of an existing building for the purpose of its maintenance or to correct damage.
Seismic hazard level.
Ground-shaking demands of specified severity, developed on either a probabilistic or deterministic basis.
Significant addition, alteration, or repair.
An addition, alteration, repair, or any combination of the preceding that affects, exposes, or reveals more than 10% of the existing building area or building elements of concern.
Site classification (site class).
A classification assigned to a site based on the types of soils present and their engineering properties, as defined in ASCE 41 or ASCE 7.
Soft story.
One or more stories constructed above an open-front garage, or other significant opening(s), with insufficient vertical elements of the lateral-resisting-system in line with, and at the level of, the open-front garage (or other significant opening(s)).
Story.
The portion of a structure between the tops of two successive finished floor surfaces and, for the topmost story, from the top of the floor finish to the top of the roof structural element.
Structural observation.
The visual observation of the structural system by a licensed design professional for general conformance to the approved construction documents.
Type of construction.
Construction classification as defined in Chapter 6 of the California Building Code.
(Ord. 2022-015 § 13)
18-48.030.1 Buildings and building elements subject to evaluation. The classifications of buildings and building elements listed in Sections 18-48.030.1.1 through 18-48.030.1.6 are subject to abatement by demolition, or by seismic evaluation and rehabilitation in accordance with Section 18-48.040 of this chapter. If abatement is proposed by demolition, a demolition permit is required to be issued prior to demolition work on any building or building element, except as provided for "emergency repairs" in the California Building Code. Buildings, building elements, or hazards which are not voluntarily abated within 365 days of notice to correct deficiencies may be required by the City to be vacated and abated in accordance with the provisions of Chapter 18-20 of this code.
18-48.030.1.1 All buildings constructed prior to December 31, 1957.
Exceptions to Section 18-48.030.1.1:
1.
Public school buildings.
2.
One-family and two-family dwellings of light-frame wood construction.
18-48.030.1.2 All buildings, regardless of when constructed, that do not meet the building benchmark criteria of ASCE 41-13, Table 4-6.
18-48.030.1.3 All buildings constructed with unreinforced masonry walls.
18-48.030.1.4 All buildings with concrete or masonry walls that were constructed or permitted prior to November 1, 2002 (the effective date of the 2001 California Building Code).
18-48.030.1.5 Suspension of lighting fixtures in suspended grid ceilings, in all buildings, regardless of when built.
18-48.030.1.6 Existing multi-story construction with one or more stories over open front or garage door opening(s), creating a "soft story" condition, as determined by a licensed design professional or the Authority Having Jurisdiction.
18-48.030.2 Timing. The requirement for seismic evaluation and abatement/rehabilitation shall be identified by the City at the time of permit application for fire sprinklers, change of use, addition, alteration, or repair of buildings and/or building elements identified in Section 18-48.030.1.
18-48.030.3 Exemptions. The project types identified in Sections 18-48.030.3.1 through 18-48.030.3.4 are exempt from the mandatory seismic evaluation requirements of this chapter.
18-48.030.3.1 Trade permits. Plumbing, mechanical, and electrical permits, in buildings with concrete and/or masonry walls, that do not significantly alter the roofing or ductwork, and that do not significantly affect or expose the building elements identified in this chapter.
18-48.030.3.2 Repairs. Small repair permits, in buildings with concrete and/or masonry walls, that do not significantly alter the roofing or ductwork, and that do not significantly affect or expose the building elements identified in this chapter.
18-48.030.3.3 Photovoltaic systems. Photovoltaic system installations that do not significantly alter the roofing, and that do not significantly affect or expose the building elements identified in this chapter.
18-48.030.3.4 Soft story alterations. Alterations, valued at less than $50,000.00, to soft story buildings that do not include any alteration, addition, or repairs to the soft story level, nor to the story directly above the soft story level.
(Ord. 2022-015 § 13)
18-48.040.1 Evaluation and rehabilitation. When a seismic evaluation is required by Section 18-48.030.1, the building owner or authorized representative shall retain a design professional, licensed in the State of California, to evaluate the building and building elements in accordance with one of the standards listed in Section 18-48.050.1 and this section. Rehabilitation and/or demolition of all deficient buildings and building elements is required in accordance with the evaluation of the licensed design professional and this chapter. The licensed design professional shall submit a written evaluation report to the Authority Having Jurisdiction which shall include, but not be limited to, the items listed in Sections 18-48.040.1.1 through 18-48.040.1.3. Unknown building elements shall be verified or otherwise addressed by the design professional retained.
18-48.040.1.1 Scope and intent. The purpose of the evaluation, a summary of the evaluation procedure(s), and the level of investigation conducted.
18-48.040.1.2 Design standard criteria. The seismic evaluation standard/criteria used, and the building performance objective chosen (minimum of life safety).
18-48.040.1.3 Site and building data. Site and building data shall include, but not be limited to, all items listed in Sections 18-48.040.1.3.1 through 18-48.040.1.3.14.
18-48.040.1.3.1 General building description. Building address, assessor's parcel number, year built, design standard/code in effect at time of original permit application, number of stories, story height, building height, building dimensions, approximate floor area, occupancy class, type of construction, historical significance, and building type.
18-48.040.1.3.2 Structural systems description. Framing, seismic-force-resisting-systems, floor and roof diaphragm construction, basement, and foundation systems. Copies of the original construction drawings shall be submitted if available.
18-48.040.1.3.3 Diaphragm chords. Diaphragm chord continuity, strength, and connections to the diaphragm web and vertical elements of the lateral force resisting system.
18-48.040.1.3.4 Diaphragm collectors. Diaphragm collector continuity, strength, and connections to the diaphragm web and vertical elements of the lateral force resisting system.
18-48.040.1.3.5 Diaphragm ties. Diaphragm tie continuity, strength, and connection to the diaphragm web elements.
18-48.040.1.3.6 Wall anchorage. Out-of-plane wall anchorage to diaphragms.
18-48.040.1.3.7 Wall strength. Out-of-plane strength of walls.
18-48.040.1.3.8 Seismic separation or interconnection. Separation and/or interconnection of adjacent buildings sharing common vertical or seismic-force-resisting elements.
18-48.040.1.3.9 Nonstructural systems description. All nonstructural elements that affect the seismic performance of the building, or whose failure could cause serious life-threatening injuries to occupants or persons near the building.
18-48.040.1.3.10 General site information. Site soil factors, soil type, seismic design category, level of seismicity, spectral response acceleration parameters, and soil site class (buildings within risk categories I or II may assume soil site class D unless site-specific geotechnical information is available).
18-48.040.1.3.11 Supplemental documentation. Photographs of the building exterior and structural elements, general condition of the structure, special features of the building, and any general comments that pertain to life safety or structural stability. Preliminary structural calculations, material test results, all necessary checklists, and summary data sheets.
18-48.040.1.3.12 General findings. A list of observed defects including cracks, uncleanliness, evidence of leaks, foundation settlement, sagging floors, rusting metal, rotting wood, and general deterioration of any other building material used.
18-48.040.1.3.13 Seismic findings. A list of seismic deficiencies identified during the inspection and/or evaluation of the structure.
18-48.040.1.3.14 Recommendations. Mitigation solutions and/or recommendations for further evaluation.
Exceptions to Section 18-48.040.1.3:
1.
In lieu of the information required by Section 18-48.040.1.3, the design professional retained may submit documentation showing the building complies with the benchmark provisions of Sections 4.3.1 through 4.3.4 of ASCE 41-13. This exception does not include evaluations of buildings known to have neglected or inadequately addressed the applicable design standards in effect at the time of original building permit application. Review of the record drawings of the structure shall be performed to confirm that the primary elements of the seismic-force-resisting system and their detailing were designed in accordance with the applicable provisions listed in Table 4-6 of ASCE 41-13. This exception does not apply to nonstructural elements, and a written report in accordance with ASCE 41-13 Section 16.17 shall be required for all nonstructural building elements identified in Section 18-48.030.1, as applicable.
2.
In lieu of the information required by Section 18-48.040.1.3, the design professional retained may submit documentation showing the building complies with the Uniform Building Code, 1955 Edition, including earthquake provisions (applicable only to buildings built prior to 1958). Documentation shall include a review of the record drawings of the structure to confirm that the primary elements of the seismic-force-resisting system were designed and detailed in accordance with applicable seismic provisions. This exception does not apply to nonstructural elements, and a written report in accordance with ASCE 41-13 Section 16.17 shall be required for all nonstructural building elements identified in Section 18-48.030.1, as applicable.
3.
As approved by the building official on a case-by-case basis, the design professional retained may submit documentation including all items specified in Exceptions 18-48.040.1.3a through 18-48.040.1.3c below in lieu of the information required by Section 18-48.040.1.3. (Structures and buildings larger than 10,000 square feet may have additional requirements).
3a.
One or more completed Tier 1 Checklists, as required by Table 4-7 of ASCE 41-13 (Life Safety Performance Level), including Quick Checks for Strength and Stiffness per Section 4.5.3 of ASCE 41-13.
3b.
A completed Summary Data Sheet found in Appendix C of ASCE 41-13 (Life Safety Performance Level).
3c.
An evaluation of diaphragms, chords, collectors, ties, and wall anchorage per Sections 7.2.9 through 7.2.11.2 of ASCE 41-13. Alternate: An evaluation of diaphragms, chords, collectors, ties, and wall anchorage per sections 12.10 and 12.11 of ASCE 7-16, with a design spectral response acceleration parameter at short periods (SDS) determined per section 12.8.1.3 of ASCE 7-16.
(Ord. 2022-015 § 13)
18-48.050.1 Evaluation and rehabilitation design standards. Seismic retrofit design and construction shall be performed under the direct supervision of a design professional, licensed in the State of California, and shall be based upon this chapter and the following standards, as adopted in Santa Rosa City Code Section 18-04.015 if not otherwise specified:
1. 
2025 California Building Code Title 24, Part 2.
2. 
2025 California Existing Building Code Title 24, Part 10.
3. 
2025 California Historical Building Code Title 24, Part 8.
4. 
ASCE 41-13 (or ASCE 41-17, Collapse Prevention Performance Level) Seismic Evaluation and Retrofit of Existing Buildings.
5. 
Any other nationally recognized standard for rehabilitation of existing buildings approved by the Building Official.
Structural observation in accordance with Section 1704 of the California Building Code shall be required for all structures in which a seismic retrofit is being performed. Structural observation shall include visual observation of work for conformance to the approved construction documents and confirmation of existing conditions assumed during design.
(Ord. 2022-015 § 13; Ord. 2026-001, 1/13/2026)