Beverly Hills Municipal Code Art. 4 Standards for Seismic Strengthening of Existing Wood- Frame Buildings With…

The purpose of this article is to promote the public welfare and safety by reducing the risk of death or injury that may result from the effects of earthquakes on existing wood-framed multi- story buildings with soft, weak or open front walls. Generally, this type of structure consists of partial tuck under parking on the first floor level with living space in the floors above. In past earthquakes many of these types of structures have performed poorly and collapsed causing loss of life, personal injury, and substantial property damage. This article creates minimum standards intended to mitigate the risk of collapse and improve the performance of these buildings during earthquakes, reducing, but not necessarily preventing, the loss of life, injury and damage to property. (Ord. 18-O-2767, eff. 1-11-2019)

Notwithstanding the applicable definitions, symbols and notations in the Building Code, the following definitions shall apply for the purposes of this article:

BUILDING CODE: Is the current Building Code adopted by the City of Beverly Hills.

CRIPPLE WALL: Is a wood-framed stud wall extending from the top of the foundation wall to the underside of the lowest floor framing.

GROUND FLOOR: Is any floor within the wood-frame portion of a building whose elevation is immediately accessible from an adjacent grade by vehicles or pedestrians. The ground floor portion of the structure does not include any floor that is completely below adjacent grades.

OPEN-FRONT WALL LINE: Is an exterior wall line lacking sufficient vertical elements of the lateral force-resisting system, which then requires tributary seismic forces to be resisted by diaphragm rotation, or requires excessive cantilever beyond parallel lines of shear walls. Diaphragms that cantilever more than twenty five percent (25%) of the distance between the first two (2) adjacent parallel lines of lateral force resisting elements from which the diaphragm cantilevers shall be considered excessive. Cantilevers shall not exceed more than six feet (6'). Diaphragm cantilevers or exterior balconies of six feet (6') or less in width shall not be considered excessive cantilevers.

OWNER OR BUILDING OWNER: Is the person, individual(s), agent, firm, corporation, or entity having legal possession, equitable interest in the property, or rights to sanction evaluation or retrofit of a building.

QUALIFIED HISTORICAL BUILDING: Is any building designated or currently in the process of being designated as a "qualified historical building" as defined in part 8, title 24 of the California Code of Regulations.

RETROFIT: Is an improvement of the seismic lateral force resisting system by alteration of the existing structural elements or addition of new structural elements.

SEISMIC DESIGN GUIDELINES: Are current guidelines developed by the building official, which are intended to calibrate, delineate and detail technical requirements to be used for the retrofitting of buildings subject to this article.

SOFT WALL LINE: Is a wall line, the lateral stiffness of which is less than what is required by story drift limitations or deformation compatibility requirements of this article. In lieu of the engineering analysis required by this article to determine whether a wall line's lateral stiffness is less than the aforementioned story drift limitations or deformation compatibility requirements, a soft wall line may be defined as a wall line in a story where the wall stiffness is less than seventy percent (70%) of the stiffness of the exterior wall above for the direction under consideration.

STORY: As used in this article, is defined as the portion of a structure between the tops of two (2) successive finished floor surfaces and, for the topmost story, from the top of the floor finish to the top of the roof structural element, but also includes any basement or underfloor space of a building exceeding four feet (4') in height.

STORY STRENGTH: Is the total strength of all seismic-resisting elements sharing the same story shear in the direction under consideration.

WALL LINE: Is any length of a wall along a principal axis of the building used to provide resistance to lateral loads.

WEAK WALL LINE: Weak wall line is a deficiency of a wall line at the ground floor in which the wall strength is less than eighty percent (80%) of the strength of the wall above in the direction under consideration. (Ord. 18-O-2767, eff. 1-11-2019)

A. The provisions of this article shall apply to all existing buildings of wood-frame construction, or wood-frame portions thereof, where:

1. A permit for construction of a new building was applied for before January 1, 1978, or if no permit can be located, the structure is determined by the City building official to have been built under Building Code standards enacted prior to January 1, 1978, and

2. The ground floor or basement portion of the structure contains parking or other similar open floor space that causes soft, weak, or open-front wall lines and there exists one or more stories above.

Notwithstanding any provision of the Building Code, compliance with this article shall not require existing electrical, plumbing, mechanical or fire-safety systems to be altered to comply with existing code unless they constitute a hazard to life or property. The existing electrical, plumbing, mechanical or fire-safety systems shall comply with the current Building Code if the seismic retrofit interferes or alters any of these systems. (Ord. 18-O-2767, eff. 1-11-2019)

The owner of each building within the scope of this article shall cause an investigation of the existing construction and a structural analysis to be made of the building by a registered civil or structural engineer in the State of California, or a qualified architect licensed by the State of California, and if the building does not meet the minimum standards specified in this article, that shall cause it to be structurally altered to conform to such standards within the time limits stated in this article.

The owner of each building within the scope of this article, which has been analyzed to demonstrate compliance or structurally altered to comply with the minimum earthquake standards in this article, shall maintain such building in conformity with the requirements of this article in effect at the time of such analysis or structural alteration.

Buildings within the scope of the article may not be added to or structurally altered or otherwise remodeled without first complying with the provisions of this article unless the building official determines that the alterations are minor in nature.

Notwithstanding any other provisions of this Code to the contrary, a building that is found to be within the scope of this article and is not brought into compliance with this article in the time frame indicated in subsection 9-5-405B, table A of this article, shall be declared unsafe and subject to the requirements of section 203 of the Uniform Administrative Code.

This provision shall not apply if alteration or repair work has commenced to bring the building into compliance with requirements of this article, and such work is proceeding in accordance with the time limits set forth in any order of the building official. (Ord. 18-O-2767, eff. 1-11-2019)

A. Engineering Report: Within the time limits shown in subsection B, table A of this section, the owner of any building that may be subject to the provisions of this article shall engage an engineer or architect to submit a properly completed screening form to the Development Services Division. The screening form is intended to demonstrate whether the structure conforms to the earthquake design provisions contained in this article. Minimum form requirements shall be as specified by the building official. Buildings determined to be outside of the scope of this article based on the screening form, shall not be required to retrofit.

B. Plan, Permits And Construction: If the screening form concludes the structure is within the scope of this article, the structure shall be strengthened to comply with the standards of this article within the time periods shown in table A of this subsection B. Minimum plan requirements and necessary permits shall be as specified by the building official.

TABLE A

TIME LIMITS FOR OWNER

C. Priority Designations: The department shall prioritize its enforcement of this article as defined in table B of this subsection C.

TABLE B

PRIORITY DESIGNATION

(Ord. 18-O-2767, eff. 1-11-2019)

A. Issuance Of Order: When the City determines that a building is within the scope of this article, the City shall issue an order as described in subsection B of this section to the owner of the building.

B. Contents Of Order: The order shall specify that the building has been determined by the building official to be within the scope of this article and, therefore, is required to meet the seismic strengthening provisions of this article. The order shall specify the building type classification and shall set forth the owner's alternatives and time limits for compliance.

C. Service Of Order: The order shall be in writing and shall be given by USPS certified mail in a sealed envelope, postage prepaid, addressed to the owner as shown on the last equalized assessment roll.

D. Failure To Receive Order: Failure of any owner to receive such notice shall not relieve the owner from compliance with this article.

E. Appeal From Order: The owner of the building may appeal the building official's determinations relative to the application and interpretation of this article to an Administrative Hearing Officer appointed pursuant to section 1-3-317 of this Code. Such appeal shall be filed with the building official within the earlier of sixty (60) days from the service date of the notice or within sixty (60) days of the date of the determination being appealed. The building official shall promptly forward the written appeal to the appointed Hearing Officer who shall schedule a public hearing to occur not less than fifteen (15) days, nor more than sixty (60) days after receipt of the written appeal. The appeal shall contain a statement of the facts on which the appeal is based sufficient to enable the Hearing Officer to understand the nature of the controversy, the basis of the appeal and the relief requested. Upon receipt of such appeal, the building official shall, by USPS certified mail, provide notice of the hearing to adjacent property owners having common boundary line with the subject building. The Hearing Officer shall conduct the hearing in accordance with the procedures set forth in section 1-3-318 of this Code. The building official, or legal representative, shall present the City's case. Within thirty (30) days of the hearing, the Hearing Officer shall prepare and serve by USPS certified mail, a written decision regarding the appeal stating all determinations and findings thereof in a clear and concise manner. The Hearing Officer shall sustain the appeal, with or without conditions, or deny the appeal. The Hearing Officer's decision shall be final. If the appeal is denied, it is the appellant's responsibility to immediately comply with this article. If the appeal is sustained with conditions, then, in addition to any other applicable violations of this article, it shall be a violation of this article for the appellant to fail to comply with those conditions. The compliance periods set forth in section 9-5-405, table A of this article, shall not be deemed tolled or extended as a result of filing any appeal that is denied.

F. Recordation: Once a building that was determined to be within the scope of this article has failed to comply with the requirements of this article within the time limits provided in subsection 9-5-405B, table A of this article, the building official shall record in the Office of the Los Angeles County Recorder a certificate stating that the subject building is within the scope of this article and requires seismic retrofit. The certificate shall also state that the owner thereof has been notified of the need to retrofit the building. Once the building has been retrofitted to comply with this article, the building official shall record a certificate indicating that the subject building no longer is in violation of this article.

G. Extensions: The building owner may request an extension to the time period for compliance set forth in subsection 9-5-405B, table A of this article. An application for extension may only be filed after the owner has submitted a Screening Report to the City and the Retrofit Plans have been approved by the City. The building owner has the burden of proof to establish with substantial evidence that good cause for the extension exists. The building owner must also provide a new proposed schedule for compliance, and plan to comply with the provisions of this article during that timeframe. Upon good cause shown, the building official may approve, approve with modifications or deny the extension request for an extension that is commensurate with the justification for the extension. (Ord. 18-O-2767, eff. 1-11-2019)

A. Notification To Tenants And Occupants: When the building official determines that a building is within the scope of this article per field survey, the owner shall advise in writing all current and prospective tenants, subtenants, lessees, sublessees, or any other person(s) entitled to the use and/or occupancy of the building of such determination. With respect to current and prospective tenants, subtenants, lessees, sublessees, or other person(s) entitled to the use and/or occupancy of the building, the property owner shall advise such persons of the building official's determination in writing. Upon compliance with this article the owner shall provide a letter of notification to the tenants indicating the current status of the building. The language of the written notifications shall be as specified by the building official.

B. Construction Means And Method Plan: The building owner shall comply with subsection 9-1-108L of this title. (Ord. 18-O-2767, eff. 1-11-2019)

Buildings designated as historical or architecturally significant landmarks on national, State or local historical registers shall also comply with the provisions of this article. At the building official's discretion, modifications to the standards set forth in this article may be permitted when such modifications are consistent with the provision of the California Historical Building Code. (Ord. 18-O-2767, eff. 1-11-2019)

A. Scope Of Analysis: As required by this article, the alteration, repair, replacement or addition of structural elements and their connections shall meet the strength and stiffness in conformance with the Building Code except as modified herein. The lateral-load-path analysis shall include the resisting elements and connections from the wood diaphragm immediately above any soft, weak or open wall lines to and including the foundation. Stories above the weak wall line shall be considered in the analysis but need not be modified. Engineer shall investigate existing conditions as applicable for the required analysis, including performing initial material testing and as-built of existing conditions. Minimum investigation requirements shall be specified by the building official.

B. Design Base Shear And Design Parameters: The design force in a given direction shall not be less than seventy five percent (75%) of the design base shear as determined based on the seismic provisions of ASCE 7 and design provisions as specified by the current Seismic Design Guidelines. The structure shall be analyzed and/or strengthened in order to mitigate the weak, open- front, and/or soft wall line deficiencies defined in section 9-5-402 of this article.

1. Exception: Alternatively, the structure may be retrofitted per appendix A4 of the California Existing Building Code, provided the entire story is analyzed and/or strengthened in order to mitigate the weak and/or soft wall line deficiencies defined in section 13.28.030.

C. Limitations To Lateral Force Resisting System: Strengthening systems with concrete walls or masonry walls, or steel braced frames shall not be permitted unless a full story analysis considering proper diaphragm stiffness and torsional behavior is performed.

D. Horizontal Structural Irregularities In Buildings With Three Or More Stories: Structures with three (3) or more stories having horizontal structural irregularities of either type 2, 3, 4, or 5 listed in ASCE 7, "Horizontal Structural Irregularities" table, shall be altered to meet the additional requirements of those sections referenced in the table for the weak or open wall lines being considered.

E. Alternate Analysis, Base Shear And Design Parameters: The building official may approve alternate analysis and/or design methodologies that meet the same performance intent as those prescribed by this article and that achieve the objectives established by this article. Design criteria shall be submitted to the City for review and approval prior to submission of plans.

F. Story Drift Limitations: The calculated story drift for each retrofitted wall line shall not exceed the allowable deformation compatible with all vertical load-resisting elements and 0.025 times the story height. Drift calculations shall be in accordance with ASCE 7 requirements and design provisions as approved by City building official.

G. Cantilever Column System: The effects of rotation and soil stiffness shall be included in the calculated story drift where lateral loads are resisted by vertical elements where required depth of embedment is determined by pole formulas or as specified by an approved geotechnical investigation report.

H. Elements Not Part Of The Lateral Force Resisting System: The requirements of the Building Code shall apply, except as modified herein. All structural framing elements along the retrofitted line and immediately adjacent to the retrofitted line and their connections not required by the design to be part of the lateral force resisting system, shall be designed and detailed to be adequate to maintain support of design dead plus live loads when subject to the expected deformations caused by seismic forces. The stress analysis of cantilever columns shall use an effective length factor of 2.1 for the direction normal to the axis of the beam.

I. Ties, Continuity And Collectors: All parts of the structure included in the scope of analysis shall be interconnected and the connection shall be capable of resisting the seismic force created by the parts being connected as required per the Building Code.

J. Anchorage Of Masonry/Concrete Structural Walls To Diaphragms: When using new masonry or concrete walls to meet the requirements of this article, proper in-plane and out-of-plane anchorage of walls into the diaphragm shall be provided per the Building Code. (Ord. 18-O-2767, eff. 1-11-2019)

A. General: For existing and new construction, the plans and specifications shall be of sufficient clarity to indicate the nature, design methodology, and extent of the proposed work and to show in detail that it will conform to the provisions of this article and other applicable section of the Building Code.

B. Engineer's Or Architect's Statement: The responsible engineer or architect shall provide the following statements on the approved plans:

I am responsible for designing this building's seismic strengthening in compliance with the minimum standards of the Mandatory Earthquake Hazard Reduction In Existing Wood-Frame Buildings with Soft, Weak or Open-Front Walls (Title 9, Chapter 5, Article 4).

C. Owner Or Owner's Representative Statement: Unless the entire building has been evaluated and retrofitted as needed to meet the full intent of the current Building Code, the owner shall provide and sign the following statement on the cover of the drawings:

I understand the seismic evaluation and strengthening performed under this project complies with the Mandatory Earthquake Hazard Reduction in Existing Wood-Frame Buildings with Soft, Weak or Open-Front Walls (Title 9, Chapter 5, Article 4) which is intended to improve the performance of the building during a seismic event. I understand the entire building has not been evaluated nor strengthened for other potential structural deficiencies that may cause a life safety concern, injury, or property damage risk resulting from a seismic event.

D. Quality Control And Assurance Requirements: General notes shall show the requirements for material testing, special inspection, structural observation and the proper installation of newly added materials. (Ord. 18-O-2767, eff. 1-11-2019)

A. Structural Observation: All structures regulated by this article require structural observation during construction. The owner shall employ the engineer or architect responsible for the structural design, or another engineer or architect designated by the engineer or qualified architect responsible for the structural design, to perform structural observation as defined in the Building Code.

B. Special Inspection: Special inspections shall be provided as required by the Building Code. Additional inspections shall be noted on drawings as required by building official. (Ord. 18-O-2767, eff. 1-11-2019)

A. Violation: Notwithstanding any other provision of this Code to the contrary, it shall be unlawful for person or business entity receiving the order described in section 9-5-406 of this article, to: 1) fail to comply with any of the time limits set forth in subsection 9-5-405B, table A of this article, including bringing the affected structure into full compliance with the minimum seismic standards specified in this article; and/or 2) maintain, use or occupy any such structure that has not been brought into full compliance within the time limits set forth in subsection 9-5-405B, table A of this article.

Any person who violates or causes or permits another person to violate this article is guilty of a misdemeanor, and shall be subject to prosecution and/or administrative enforcement under this Code. For purposes of this paragraph, "any person" includes an owner, lessor, sublessor, manager or person in control of a building subject to this article. This term shall not include any person who is merely a tenant or other individual occupying any dwelling unit, efficiency dwelling unit, guest room or suite in a building. The legal owner of a building is that person, firm, corporation, partnership or other entity whose name or title appears on the record with the Office of the County Recorder, as well as all successors or assignees of these persons.

B. Exception: This section shall not apply to any building on which work is proceeding in compliance with the time limits set forth in this article, or in compliance with any extensions of time granted by the building official; or any action, order or determination made by the building official in the implementation of this article. (Ord. 18-O-2767, eff. 1-11-2019)