Chapter 15.31 — DISASTER REPAIR AND RECONSTRUCTION

This chapter establishes standards and regulations for the expeditious reconstruction of structures damaged as a result of a disaster for which a local emergency has been declared by the city council. The chapter does not allow exemptions from the building, fire, electrical, mechanical, plumbing, other codes, or city ordinances.

(Ord. 1532 § 2, 2013)

• A. The provisions of this chapter are applicable to all buildings and structures regulated by the city following each disaster after a local emergency has been declared by the city council.

• B. The requirements of this chapter may be waived by the building official subject to an engineering evaluation as defined in Section 15.31.030.

• (Ord. 1532 § 2, 2013)

For the purpose of this chapter, the following definitions apply:

"Architect" means a person licensed by the state of California to practice architecture as prescribed by the state of California Business and Professions Code.

"Building official" is the officer or other designated authority charged with the administration and enforcement of this chapter or duly authorized representative.

"Civil engineer" means a person registered by the state of California to practice civil engineering as prescribed by the state of California Business and Professions Code.

"Current code" means the edition of the California Building Code as published by the International Code Council as adopted by the city in accordance with operation of law pursuant to Section 18941.5 of the state of California Health and Safety Code. The edition to be applied shall be that edition in effect at the time of the declaration of a local emergency by the city council.

"Engineering evaluation" is an evaluation of a damaged building or structure, or suspected damaged building or structure, performed under the direction of a structural engineer, civil engineer, or architect retained by the owner of the building or structure. Engineering evaluations shall, at a minimum, contain recommendations for repair with appropriate opinion of construction cost for those repairs. All engineering evaluations shall include the engineer's or architect's stamp, wet-signature and license expiration date.

"Substantial structural damage" is a condition where:

1. In any story, the vertical elements of the lateral-force-resisting system, have suffered damage such that the lateral load-carrying capacity of the structure in any direction has been reduced by more than twenty percent from its pre-damaged condition, or

2. The capacity of any vertical gravity load-carrying component, or any group of such components, that supports more than thirty percent of the total area of the structure's floor(s) and roof(s) has been reduced more than twenty percent from its pre-damaged condition, and the remaining capacity of such affected elements with respect to all dead and live loads is less than seventy-five percent of that required by the building code for new buildings of similar structure, purpose, and location.

(Ord. 1532 § 2, 2013)

• A. Buildings and structures of all occupancies which have been damaged as the result of a disaster, except as otherwise noted, shall be repaired in accordance with the following criteria:

  1. When the estimated value of repair does not exceed ten percent of the replacement value of the structure, the damaged portion may be restored to the pre-disaster condition; except that when the damaged elements include suspended ceiling systems, the ceiling system shall be repaired with all bracing required by current code.

  2. When the estimated value of repair is greater than ten percent the replacement value of the structure, the damaged elements shall be repaired and/or brought into conformance with structural requirements of the current codes.

• B. For the purposes of this chapter, the following repair requirements are hereby added as a new Subsection 3403.5 to Section 3403 Additions, Alterations or Repair in the 2013 California Building Code (CBC):

3403.5.1 Repairs. Repairs of structural elements shall comply with this section.

3403.5.1.1 Seismic Evaluation and Design. Seismic evaluation and design of an existing building and its components shall be based on the following criteria:

3403.5.1.1.1 Evaluation and Design Procedures. The seismic evaluation and design shall be based on the procedures specified in the building code, ASCE 31 Seismic Evaluation of Existing Buildings (for evaluation only) or ASCE 41 Seismic Rehabilitation of Existing Buildings . The procedures contained in Appendix A of the International Existing Building Code shall be permitted to be used as specified in Section 3403.5.1.1.3.

3403.5.1.1.2 CBC Level Seismic Forces. When seismic forces are required to meet the building code level, they shall be one of the following:

1. 100 percent of the values in the building code. The R factor used for analysis in accordance with Chapter 16 of the building code shall be the R factor specified for structural systems classified as "Ordinary" unless it can be demonstrated that the structural system satisfies the proportioning and detailing requirements for systems classified as "Intermediate" or "Special."

2. Forces corresponding to BSE-1 and BSE-2 Earthquake Hazard Levels defined in ASCE 41. Where ASCE 41 is used, the corresponding performance levels shall be those shown in Table 3403.5.1.1.2.

Text read from an image; its layout may differ:
TABLE 3403.5.1.1.2
ASCE 41 and ASCE 31 PERFORMANCE LEVELS
OCCUPANCY PERFORMANCE LEVEL FOR USE PERFORMANCE LEVEL FOR
CATEGORY (BASED WITH ASCE 31 AND WITH ASCE USE WITH ASCE 41 BSE-2
ON IBC TABLE 41 BSE-1 EARTHQUAKE HAZARD EARTHQUAKE HAZARD
1604.5) LEVEL LEVEL
I Life Safety (LS) Collapse Prevention (CP)
II Life Safety (LS) Collapse Prevention (CP)
III Note (a) Note (a)
IV Immediate Occupancy (IO) Life Safety (LS)

• a. Performance Levels for Occupancy Category III shall be taken as halfway between the performance levels specified for Occupancy Category II and Occupancy Category IV.

3403.5.1.1.3 Reduced CBC Level Seismic Forces. When seismic forces are permitted to meet reduced building code levels, they shall be one of the following:

1. 75 percent of the forces prescribed in the building code. The R factor used for analysis in accordance with Chapter 16 of the building code shall be the R factor as specified in Section 3403.5.1.1.2.

2. In accordance with the applicable chapters in Appendix A of the International Existing Building Code as specified in Items 2.1 through 2.5 below. Structures or portions of structures that comply with the requirements of the applicable chapter in Appendix A shall be deemed to comply with the requirements for reduced building code force levels.

   • 2.1. The seismic evaluation and design of unreinforced masonry bearing wall buildings in Occupancy Category I or II are permitted to be based on the procedures specified in Appendix Chapter A1.

   • 2.2. Seismic evaluation and design of the wall anchorage system in reinforced concrete and reinforced masonry wall buildings with flexible diaphragms in Occupancy Category I or II are permitted to be based on the procedures specified in Appendix Chapter A2.

   • 2.3. Seismic evaluation and design of cripple walls and sill plate anchorage in residential buildings of light-frame wood construction in Occupancy Category I or II are permitted to be based on the procedures specified in Appendix Chapter A3.

   • 2.4. Seismic evaluation and design of soft, weak, or open-front wall conditions in multiunit residential buildings of wood construction in Occupancy Category I or II are permitted to be based on the procedures specified in Appendix Chapter A4.

   • 2.5. Seismic evaluation and design of concrete buildings and concrete with masonry infill buildings in all Occupancy Categories are permitted to be based on the procedures specified in Appendix Chapter A5.

3. In accordance with ASCE 31 based on the applicable performance level as shown in Table 3403.5.1.1.2.

4. Those associated with the BSE-1 Earthquake Hazard Level defined in ASCE 41 and the performance level as shown in Table 3403.5.1.1.2. Where ASCE 41 is used, the design spectral response acceleration parameters Sxs and Sx1 shall not be taken less than 75 percent of the respective design spectral response acceleration parameters SDS and SD1 defined by the California Building Code and its reference standards.

3403.5.1.2 Wind Design. Wind design of existing buildings shall be based on the procedures specified in the building code.

3403.5.2 Repairs to Damaged Buildings. Repairs to damaged buildings shall comply with this section.

• 3403.5.2.1 Unsafe Conditions. Regardless of the extent of structural damage, unsafe conditions shall be eliminated.

• 3403.5.2.2 Substantial Structural Damage to Vertical Elements of the LateralForce-Resisting System. A building that has sustained substantial structural damage to the vertical elements of its lateral-force-resisting system shall be evaluated and repaired in accordance with the applicable provisions of Sections 3403.5.2.2.1 through 3403.5.2.2.3.

• 3403.5.2.2.1 Evaluation. The building shall be evaluated by a registered design professional, and the evaluation findings shall be submitted to the code official. The evaluation shall establish whether the damaged building, if repaired to its pre-damage state, would comply with the provisions of the building code. Wind forces for this evaluation shall be those prescribed in the building code. Seismic forces for this evaluation are permitted to be the reduced level seismic forces specified in Code Section 3403.5.1.1.3.

• 3403.5.2.2.2 Extent of Repair for Compliant Buildings. If the evaluation establishes compliance of the pre-damage building in accordance with Section 3403.5.2.2.1, then repairs shall be permitted that restore the building to its pre-damage state, using materials and strengths that existed prior to the damage.

3403.5.2.2.3 Extent of Repair for Non-Compliant Buildings. If the evaluation does not establish compliance of the pre-damage building in accordance with Section 3403.5.2.2.1, then the building shall be rehabilitated to comply with applicable provisions of the building code for load combinations including wind or seismic forces. The wind design level for the repair shall be as required by the building code in effect at the time of original construction unless the damage was caused by wind, in which case the design level shall be as required by the code in effect at the time of original construction or as required by the building code, whichever is greater. Seismic forces for this rehabilitation design shall be those required for the design of the pre-damaged building, but not less than the reduced level seismic forces specified in Section 3403.5.1.1.3. New structural members and connections required by this rehabilitation design shall comply with the detailing provisions of the building code for new buildings of similar structure, purpose, and location.

3403.5.2.3 Substantial Structural Damage to Vertical Load-Carrying Components. Vertical load-carrying components that have sustained substantial structural damage shall be rehabilitated to comply with the applicable provisions for dead and live loads in the building code. Undamaged vertical load-carrying components that receive dead or live loads from rehabilitated components shall also be rehabilitated to carry the design loads of the rehabilitation design. New structural members and connections required by this rehabilitation design shall comply with the detailing provisions of the building code for new buildings of similar structure, purpose, and location.

3403.5.2.3.1 Lateral Force-Resisting Elements. Regardless of the level of damage to vertical elements of the lateral force-resisting system, if substantial structural damage to vertical load-carrying components was caused primarily by wind or seismic effects, then the building shall be evaluated in accordance with Section 3403.5.2.2.1 and, if non-compliant, rehabilitated in accordance with Section 3403.5.2.2.3.

3403.5.2.4 Less than Substantial Structural Damage. For damage less than substantial structural damage, repairs shall be allowed that restore the building to its pre-damage state, using materials and strengths that existed prior to the damage. New structural members and connections used for this repair shall comply with the detailing provisions of the building code for new buildings of similar structure, purpose, and location.

3403.5.3 Referenced Standards.

ASCE 31-03, Seismic Evaluation of Existing Buildings, California Building Code 3403.5.1.1.1, TABLE 3403.5.1.1.2, 3403.5.1.1.3.

ASCE 41-06, Seismic Rehabilitation of Existing Buildings, California Building Code, 3403.5.1.1.1, 3403.5.1.1.2, TABLE 3403.5.1.1.2, 3403.5.1.1.3.

(Ord. 1532 § 2, 2013)

• A. All damaged chimneys must be repaired or reconstructed to comply with the requirements of Chapter 21 of the California Building Code. Damaged portions of chimneys shall be removed in accordance with the following criteria:

  1. When the damaged portion of the chimney is located between the roof line and the top of the chimney, the damaged portion may be removed to the roof line provided the roof and ceiling anchorage are in sound condition. The reconstruction portion of the chimney shall be braced to the roof structure using an approved method.

  2. Of a single-story structure in which the damaged portion of the chimney is below the roof line or the damaged portion extends from above the roof line to below the roof line, the chimney may be removed to the top of the firebox.

  3. For a multistory structure, the damaged portion of the chimney shall be removed from the top to a floor line where anchorage is found.

  4. In any structure where the firebox has been damaged, the entire chimney and firebox shall be removed to the foundation. If the foundation is in sound condition, the firebox and chimney may be reconstructed using the existing foundation. If the foundation has been damaged, the foundation shall be removed and replaced.

• B. Where existing conditions preclude the installation of all anchorage required by Chapter 21 of the California Building Code, alternate systems may be used in accordance with the alternate methods and materials provisions of the California Building Code when approved by the Building Official.

• C. Where the portion of the chimney extending above the roof line exceeds two times the least dimension of the chimney, that portion above the roof line shall be braced to the roof structure using an approved method.

• (Ord. 1532 § 2, 2013)

• A. Buildings or structures which are included on a national, state, or local register for historic places or which are qualifying structures within a recognized historic district, which have been damaged as a result of a disaster, shall have an engineering evaluation performed.

• B. The minimum criteria for repair shall be as included in Section 15.31.040, Repair criteria, with due consideration given to the historical rating and nature of the structures. Additional standards and criteria, as noted in Part 8, Title 24, California Code shall apply.

• C. Where conflicts exists between the standards contained herein and the state of California Historic Building Code, the Historic Building Code shall govern.

• (Ord. 1532 § 2, 2013)

All damaged buildings determined to be bearing wall buildings constructed of unreinforced masonry shall be repaired and strengthened to fully comply with the requirements of the Uniform Code for Building Conservation as adopted by the city. (Ord. 1532 § 2, 2013)