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San Francisco Overview
San Francisco Charter
San Francisco Administrative Code
ADMINISTRATIVE CODE
THE SAN FRANCISCO CODES
PREFACE TO THE ADMINISTRATIVE CODE
CHAPTER 1: GENERAL PROVISIONS
CHAPTER 2: BOARD OF SUPERVISORS
CHAPTER 2A: EXECUTIVE BRANCH
CHAPTER 2B: ASSESSMENT APPEALS BOARDS (TAX APPEAL BOARDS)
CHAPTER 3: BUDGET PROCEDURES
CHAPTER 4: CITY BUILDINGS, EQUIPMENT, AND VEHICLES
CHAPTER 5: COMMITTEES
CHAPTER 6: PUBLIC WORKS CONTRACTING POLICIES AND PROCEDURES
CHAPTER 7: DISASTER COUNCIL
CHAPTER 8: DOCUMENTS, RECORDS AND PUBLICATIONS
CHAPTER 9A: FARMERS' MARKET
CHAPTER 9B: FLEA MARKET
CHAPTER 10: FINANCE, TAXATION, AND OTHER FISCAL MATTERS
CHAPTER 10A: [REQUEST FOR SHERIFF’S SERVICES]*
CHAPTER 10B: SPECIAL LAW ENFORCEMENT AND PUBLIC WORKS SERVICES
CHAPTER 10C: REIMBURSEMENT FOR TOWING AND STORAGE OF VEHICLES
CHAPTER 10E: PLANNING MONITORING
CHAPTER 10F: 1660 MISSION STREET SURCHARGE
CHAPTER 10G: BOARD OF APPEALS SURCHARGE FOR PERMITS AND FEES
CHAPTER 10H: RECOVERY OF COSTS OF EMERGENCY RESPONSE
CHAPTER 11: FRANCHISES
CHAPTER 12: HOUSING AUTHORITY
CHAPTER 12A: HUMAN RIGHTS COMMISSION
CHAPTER 12D: MINORITY/WOMEN/LOCAL BUSINESS UTILIZATION
CHAPTER 12E: BAN ON CITY USE OF GAS-POWERED LANDSCAPING EQUIPMENT
CHAPTER 12F: IMPLEMENTING THE MACBRIDE PRINCIPLES - NORTHERN IRELAND
CHAPTER 12G: PROHIBITION ON USE OF PUBLIC FUNDS FOR POLITICAL ACTIVITY BY RECIPIENTS OF CITY CONTRACTS, GRANTS, AND LOANS
CHAPTER 12H: IMMIGRATION STATUS
CHAPTER 12I: CIVIL IMMIGRATION DETAINERS
CHAPTER 12J: CITY BUSINESS WITH BURMA PROHIBITED
CHAPTER 12L: PUBLIC ACCESS TO RECORDS AND MEETINGS OF NONPROFIT ORGANIZATIONS
CHAPTER 12M: PROTECTION OF PRIVATE INFORMATION*
CHAPTER 12N: LESBIAN, GAY, BISEXUAL, TRANSGENDER, QUEER, AND QUESTIONING YOUTH: YOUTH SERVICES SENSITIVITY TRAINING
CHAPTER 12O: EARNED INCOME CREDIT INFORMATION
CHAPTER 12S: WORKING FAMILIES CREDIT PROGRAM
CHAPTER 12X: [REPEALED]*
CHAPTER 12Y: SAN FRANCISCO SLAVERY DISCLOSURE ORDINANCE*
CHAPTER 13: JAILS AND PRISONERS
CHAPTER 14A: DISADVANTAGED BUSINESS ENTERPRISE PROGRAM
CHAPTER 14B: LOCAL BUSINESS ENTERPRISE UTILIZATION AND NON-DISCRIMINATION IN CONTRACTING ORDINANCE
CHAPTER 14C: [EXPIRED]
CHAPTER 15: MENTAL HEALTH SERVICE
CHAPTER 16: OFFICERS AND EMPLOYEES GENERALLY
CHAPTER 17: PUBLIC OFF-STREET PARKING FACILITIES
CHAPTER 18: PAYROLL PROCEDURE
CHAPTER 19. COMMUNITY SAFETY CAMERA ORDINANCE
CHAPTER 19A: PUBLIC HEALTH
CHAPTER 19B: ACQUISITION OF SURVEILLANCE TECHNOLOGY
CHAPTER 20: SOCIAL SERVICES
CHAPTER 21: ACQUISITION OF COMMODITIES AND SERVICES
CHAPTER 21A: HEALTH-RELATED COMMODITIES AND SERVICES
CHAPTER 21B: COMMODITIES AND SERVICES RELATING TO PROJECTS ADDRESSING HOMELESSNESS
CHAPTER 21D: FOOD PURCHASES AT HOSPITALS OPERATED BY THE DEPARTMENT OF PUBLIC HEALTH AND JAILS OPERATED BY THE SHERIFF’S DEPARTMENT
CHAPTER 21E: GOODS OR SERVICES CONTRACTS FOR INCARCERATED PERSONS
CHAPTER 21F: SAN FRANCISCO PUBLIC UTILITIES COMMISSION SOCIAL IMPACT PARTNERSHIP PROGRAM.
CHAPTER 21G: GRANTS
CHAPTER 22: RADIO COMMUNICATION FACILITIES
CHAPTER 22A: INFORMATION AND COMMUNICATION TECHNOLOGY
CHAPTER 22B: TELECOMMUNICATIONS FACILITIES
CHAPTER 22C: PUBLIC INTERNET ACCESS
CHAPTER 22D: OPEN DATA POLICY
CHAPTER 22E: CITY-OWNED FIBER-OPTIC FACILITIES
CHAPTER 22G: OFFICE OF EMERGING TECHNOLOGY
CHAPTER 22H: DESIGNATION UNDER HEALTH INSURANCE PORTABILITY AND ACCOUNTABILITY ACT (HIPAA)
CHAPTER 22I: OFFICE OF CYBER SECURITY AND DUTIES OF THE CHIEF INFORMATION SECURITY OFFICER
CHAPTER 23: REAL PROPERTY TRANSACTIONS
CHAPTER 23A: SURPLUS PUBLIC LANDS ORDINANCE
CHAPTER 24: REDEVELOPMENT AGENCY
CHAPTER 24A: ADMINISTRATIVE STRUCTURE LOCAL RENT SUPPLEMENT PROGRAM IN THE OFFICE OF MAYOR
CHAPTER 24B: RELOCATION APPEALS BOARD
CHAPTER 25: STREET LIGHTING
CHAPTER 26. DEEMED APPROVED OFF-STREET ALCOHOL USE NUISANCE REGULATIONS
CHAPTER 27: HEALTHY NAIL SALON RECOGNITION PROGRAM
CHAPTER 28: ADMINISTRATIVE DEBARMENT PROCEDURE
CHAPTER 29: FINDINGS OF FISCAL RESPONSIBILITY AND FEASIBILITY
CHAPTER 29A: APPROVAL OF POWER PLANT; PLANNING CODE SEC. 303(q) CRITERIA
CHAPTER 29B: CHILD CARE FEASIBILITY STUDY FOR CITY AND CITY-FUNDED PROJECTS
CHAPTER 30: CENTRALIZATION OF WORKFORCE DEVELOPMENT
CHAPTER 31: CALIFORNIA ENVIRONMENTAL QUALITY ACT PROCEDURES AND FEES
CHAPTER 32: RESIDENTIAL REHABILITATION LOAN PROGRAM
CHAPTER 33: COMMISSION ON THE STATUS OF WOMEN
CHAPTER 33A: LOCAL IMPLEMENTATION OF THE UNITED NATIONS CONVENTION ON THE ELIMINATION OF ALL FORMS OF DISCRIMINATION AGAINST WOMEN (CEDAW)*
CHAPTER 34: NOTIFICATION TO ASSESSOR CONCERNING ZONING RECLASSIFICATIONS OF PROPERTY, CONDITIONAL USE PERMITS AND VARIANCES
CHAPTER 35: RESIDENTIAL, HOTEL, AND PDR COMPATIBILITY AND PROTECTION
CHAPTER 36: COMMUNITY IMPROVEMENTS AREA PLANS AND PROGRAMS
CHAPTER 37: RESIDENTIAL RENT STABILIZATION AND ARBITRATION ORDINANCE
CHAPTER 37A: RENT STABILIZATION AND ARBITRATION FEE
CHAPTER 37B: MIDTOWN PARK APARTMENTS
CHAPTER 37C: EVICTION PROTECTIONS FOR COMMERCIAL TENANTS DURING COVID-19 PANDEMIC
CHAPTER 38: COMMERCIAL LANDLORDS; ACCESS IMPROVEMENT OBLIGATIONS AND NOTICE TO SMALL BUSINESS TENANTS REGARDING DISABILITY ACCESS
CHAPTER 39: [RIGHT TO RETURN TO REVITALIZED PUBLIC HOUSING]
CHAPTER 40: HOUSING CODE ENFORCEMENT LOAN PROGRAM
CHAPTER 41: RESIDENTIAL HOTEL UNIT CONVERSION AND DEMOLITION
CHAPTER 41A: RESIDENTIAL UNIT CONVERSION AND DEMOLITION
CHAPTER 41B: COMMUNITY OPPORTUNITY TO PURCHASE ACT
CHAPTER 41C: TIME-SHARE CONVERSION ORDINANCE
CHAPTER 41D: RESIDENTIAL HOTEL VISITOR POLICIES
CHAPTER 41E. RESIDENTIAL HOTEL MAIL RECEPTACLE ORDINANCE
CHAPTER 41F: TOURIST HOTEL CONVERSION*
CHAPTER 41G: RESIDENTIAL HOTEL COVID-19 PROTECTIONS
CHAPTER 42: INDUSTRIAL DEVELOPMENT AUTHORITY
CHAPTER 43: MUNICIPAL FINANCE LAW
CHAPTER 44: ADULT DAY HEALTH CARE PLANNING COUNCIL
CHAPTER 45: JURY FEES
CHAPTER 47: PREFERENCE IN CITY AFFORDABLE HOUSING PROGRAMS
CHAPTER 48: RENTAL SUBSIDY PROGRAM FOR LOW-INCOME FAMILIES
CHAPTER 49: SECURITY DEPOSITS FOR RESIDENTIAL RENTAL PROPERTY
CHAPTER 49A: RESIDENTIAL TENANT COMMUNICATIONS
CHAPTER 49B: RESIDENTIAL RENTAL UNITS: LOCK REPLACEMENTS BY LANDLORD WHEN TENANTS VACATE
CHAPTER 50: NONPROFIT PERFORMING ARTS LOAN PROGRAM
CHAPTER 51: VOLUNTARY ARTS CONTRIBUTIONS PROGRAM
CHAPTER 52: SAN FRANCISCO CARBON MITIGATION PROGRAM
CHAPTER 53: URBAN AGRICULTURE
CHAPTER 53A: URBAN AGRICULTURE INCENTIVE ZONES ACT PROCEDURES
CHAPTER 54: SOUTHEAST COMMUNITY FACILITY COMMISSION
CHAPTER 56: DEVELOPMENT AGREEMENTS
CHAPTER 57: FILM COMMISSION
CHAPTER 58: RIGHT TO COUNSEL IN CIVIL MATTERS
CHAPTER 58A: RIGHT TO CIVIL COUNSEL FOR VICTIMS OF DOMESTIC VIOLENCE
CHAPTER 59: HEALTHY FOOD RETAILER ORDINANCE
CHAPTER 59A: FOOD SECURITY AND EQUITY REPORTS
CHAPTER 60: ASSISTED HOUSING PRESERVATION ORDINANCE
CHAPTER 61: WATERFRONT LAND USE
CHAPTER 62: DOMESTIC PARTNERSHIPS
CHAPTER 63: WATER EFFICIENT IRRIGATION ORDINANCE*
CHAPTER 64: CITY EMPLOYEE AND CITY CONTRACTOR SAFETY AND HEALTH
CHAPTER 65: RENT REDUCTION AND RELOCATION PLAN FOR TENANTS INCONVENIENCED BY SEISMIC WORK PERFORMED PURSUANT TO CHAPTERS 14 AND 15 OF THE SAN FRANCISCO BUILDING CODE
CHAPTER 65A: COMPENSATION, OR SUBSTITUTE HOUSING SERVICE, FOR TENANTS AFFECTED BY TEMPORARY SEVERANCE OF SPECIFIED HOUSING SERVICES DURING MANDATORY SEISMIC WORK REQUIRED BY BUILDING CODE CHAPTER 34B
CHAPTER 66: SEISMIC SAFETY RETROFIT PROGRAM
CHAPTER 67: THE SAN FRANCISCO SUNSHINE ORDINANCE OF 1999
CHAPTER 67A: CELL PHONES, PAGERS AND SIMILAR SOUND-PRODUCING ELECTRICAL DEVICES
CHAPTER 67B: PARENTAL LEAVE AND TELECONFERENCING
CHAPTER 68: CULTURAL EQUITY ENDOWMENT FUND
CHAPTER 69: SAN FRANCISCO HEALTH AUTHORITY
CHAPTER 70: IN-HOME SUPPORTIVE SERVICES PUBLIC AUTHORITY
CHAPTER 71: MILLS ACT CONTRACT PROCEDURES
CHAPTER 72: RELOCATION ASSISTANCE FOR LEAD HAZARD REMEDIATION
CHAPTER 74: RENT ESCROW ACCOUNT PROGRAM
CHAPTER 77: BUILDING INSPECTION COMMISSION APPEALS
CHAPTER 78: DEPARTMENT OF BUILDING INSPECTION PERMIT TRACKING SYSTEM
CHAPTER 79: PREAPPROVAL NOTICE FOR CERTAIN CITY PROJECTS
CHAPTER 79A: ADDITIONAL PREAPPROVAL NOTICE FOR CERTAIN CITY PROJECTS
CHAPTER 80: ANTI-BLIGHT ENFORCEMENT PROCEDURE
CHAPTER 80A: ORDERS TO VACATE DUE TO HAZARDOUS HOUSING CONDITIONS
CHAPTER 82: LOCAL HIRING POLICY FOR CONSTRUCTION
CHAPTER 83: FIRST SOURCE HIRING PROGRAM
CHAPTER 84: SAN FRANCISCO RESIDENTIAL RENT ASSISTANCE PROGRAM FOR PERSONS DISQUALIFIED FROM FEDERAL RENT SUBSIDY PROGRAMS BY THE FEDERAL QUALITY HOUSING AND WORK RESPONSIBILITY ACT OF 1998 (QHWRA)
CHAPTER 85: THE HOUSING INNOVATION PROGRAM
CHAPTER 86: CHILDREN AND FAMILIES FIRST COMMISSION
CHAPTER 87: FAIR HOUSING IMPLEMENTATION ORDINANCE
CHAPTER 88: PERFORMANCE AND REVIEW ORDINANCE OF 1999
CHAPTER 89: DEPARTMENT OF CHILD SUPPORT SERVICES
CHAPTER 90: ENTERTAINMENT COMMISSION
CHAPTER 90A: PROMOTING AND SUSTAINING MUSIC AND CULTURE
CHAPTER 91: LANGUAGE ACCESS
CHAPTER 92: REAL ESTATE LOAN COUNSELING AND EDUCATION
CHAPTER 93: PREGNANCY INFORMATION DISCLOSURE AND PROTECTION ORDINANCE
CHAPTER 94: THE SAN FRANCISCO PLAZA PROGRAM
CHAPTER 94A: THE SAN FRANCISCO SHARED SPACES PROGRAM
CHAPTER 95: IDENTIFICATION CARDS
CHAPTER 96: COORDINATION BETWEEN THE POLICE DEPARTMENT AND THE DEPARTMENT OF POLICE ACCOUNTABILITY
CHAPTER 96A: LAW ENFORCEMENT REPORTING REQUIREMENTS
CHAPTER 96B: POLICY MAKING MARIJUANA OFFENSES THE LOWEST LAW ENFORCEMENT PRIORITY
CHAPTER 96C: POLICE INTERROGATION OF YOUTH - JEFF ADACHI YOUTH RIGHTS ORDINANCE
CHAPTER 96D: PRESENTATION OF YOUTH CASES
CHAPTER 96E [DOMESTIC VIOLENCE DATA REPORTING]*
CHAPTER 96F: COMMUNITY POLICING PLANS
CHAPTER 96G: LIMITS ON POLICE DEPARTMENT USE AND STORAGE OF DNA PROFILES
CHAPTER 96H: LAW ENFORCEMENT EQUIPMENT POLICIES
CHAPTER 97: HEALTHCARE IMPACT REPORTS
CHAPTER 98: THE BETTER STREETS POLICY
CHAPTER 99: PUBLIC POWER IN NEW CITY DEVELOPMENTS
CHAPTER 100: PROCEDURES GOVERNING THE IMPOSITION OF ADMINISTRATIVE FINES
CHAPTER 101: RESTRICTING THE PURCHASE, SALE, OR DISTRIBUTION OF SUGAR-SWEETENED BEVERAGES BY OR FOR THE CITY
CHAPTER 102: OUR CHILDREN, OUR FAMILIES COUNCIL
CHAPTER 103: NON-COOPERATION WITH IDENTITY-BASED REGISTRY ORDINANCE
CHAPTER 104: COLLECTION OF SEXUAL ORIENTATION AND GENDER IDENTITY DATA
CHAPTER 105: CIGARETTE LITTER ABATEMENT FEE ORDINANCE
CHAPTER 106: CITY NAVIGATION CENTERS
CHAPTER 107: CULTURAL DISTRICTS
CHAPTER 107A: AFRICAN AMERICAN ARTS AND CULTURAL DISTRICT
CHAPTER 107B: CASTRO LESBIAN, GAY, BISEXUAL, TRANSGENDER, AND QUEER (LGBTQ) CULTURAL DISTRICT
CHAPTER 107C: AMERICAN INDIAN CULTURAL DISTRICT
CHAPTER 107D: SUNSET CHINESE CULTURAL DISTRICT
CHAPTER 109: PRIORITIZING 100% AFFORDABLE HOUSING
CHAPTER 111: HOUSING REPORTS FOR SENIORS AND PEOPLE WITH DISABILITIES
CHAPTER 115: AUTOMATED POINT OF SALE STATION REGISTRATION AND INSPECTION ORDINANCE
CHAPTER 116: COMPATIBILITY AND PROTECTION FOR RESIDENTIAL USES AND PLACES OF ENTERTAINMENT
CHAPTER 117: COOPERATIVE LIVING OPPORTUNITIES FOR MENTAL HEALTH PROGRAM
CHAPTER 118: PLACE FOR ALL PROGRAM
CHAPTER 119: SAFE PARKING PROGRAMS
CHAPTER 120: ADMINISTRATION OF AFFORDABLE HOUSING FUNDS
CHAPTER 121: CLOSURE OF JUVENILE HALL
CHAPTER 122: CLOSURE OF COUNTY JAIL 4
CHAPTER 123: LIBRARY LAUREATE PROGRAMS
APPENDIX: Table of Initiative Ordinances and Policy Declarations
References to Ordinances
San Francisco Business and Tax Regulations Code
BUSINESS AND TAX REGULATIONS CODE
THE SAN FRANCISCO CODES
PREFACE TO THE BUSINESS AND TAX REGULATIONS CODE
ARTICLE 1: PERMIT PROCEDURES
ARTICLE 2: LICENSE FEES
ARTICLE 3: [REPEALED]
ARTICLE 4: [RESERVED]
ARTICLE 5: ELECTRICAL MUSICAL DEVICES
ARTICLE 6: COMMON ADMINISTRATIVE PROVISIONS
ARTICLE 7: TAX ON TRANSIENT OCCUPANCY OF HOTEL ROOMS
ARTICLE 8: SUGARY DRINKS DISTRIBUTOR TAX ORDINANCE
ARTICLE 9: TAX ON OCCUPANCY OF PARKING SPACE IN PARKING STATIONS
ARTICLE 10: UTILITY USERS TAX
ARTICLE 10B: ACCESS LINE TAX
ARTICLE 11: STADIUM OPERATOR ADMISSION TAX
ARTICLE 12: BUSINESS REGISTRATION
ARTICLE 12-A: [REPEALED]
ARTICLE 12-A-1: GROSS RECEIPTS TAX ORDINANCE
ARTICLE 12-B: [REPEALED]
ARTICLE 12B-1: NEIGHBORHOOD BEAUTIFICATION AND GRAFFITI CLEAN-UP FUND TAX OPTION
ARTICLE 12-C: REAL PROPERTY TRANSFER TAX
ARTICLE 12-D: UNIFORM LOCAL SALES AND USE TAX
ARTICLE 13: CONNECTIONS TO THE POLICE DEPARTMENT TERMINAL ALARM PANEL
ARTICLE 14: TRANSPORTATION AUTHORITY
ARTICLE 15: BUSINESS IMPROVEMENT DISTRICTS PROCEDURE CODE
ARTICLE 15A: PUBLIC REALM LANDSCAPING, IMPROVEMENT AND MAINTENANCE ASSESSMENT DISTRICTS ("GREEN BENEFIT DISTRICTS")
ARTICLE 16: [REPEALED]
ARTICLE 17: [REPEALED]
ARTICLE 20: FINANCIAL INFORMATION PRIVACY ORDINANCE
ARTICLE 21: EARLY CARE AND EDUCATION COMMERCIAL RENTS TAX ORDINANCE
ARTICLE 22: PARKING STATIONS; REVENUE CONTROL EQUIPMENT
ARTICLE 23: VEHICLE REGISTRATION FEE EXPENDITURE PLAN
ARTICLE 28: HOMELESSNESS GROSS RECEIPTS TAX ORDINANCE
ARTICLE 29: VACANCY TAX ORDINANCE
ARTICLE 29A: EMPTY HOMES TAX ORDINANCE
ARTICLE 30: CANNABIS BUSINESS TAX
ARTICLE 32: TRAFFIC CONGESTION MITIGATION TAX
ARTICLE 33: OVERPAID EXECUTIVE GROSS RECEIPTS TAX
ARTICLE 36: [REPEALED]
ARTICLE 37: FAIR WAGES FOR EDUCATORS PARCEL TAX ORDINANCE
References to Ordinances
San Francisco Campaign and Governmental Conduct Code
San Francisco Environment Code
ENVIRONMENT CODE
THE SAN FRANCISCO CODES
PREFACE TO THE ENVIRONMENT CODE
CHAPTER 1: PRECAUTIONARY PRINCIPLE POLICY STATEMENT
CHAPTER 2: ENVIRONMENTALLY PREFERABLE PURCHASING ORDINANCE
CHAPTER 3: INTEGRATED PEST MANAGEMENT PROGRAM
CHAPTER 4: HEALTHY AIR AND CLEAN TRANSPORTATION PROGRAM
CHAPTER 5: RESOURCE CONSERVATION ORDINANCE
CHAPTER 7: MUNICIPAL GREEN BUILDING REQUIREMENTS*
CHAPTER 8: TROPICAL HARDWOOD AND VIRGIN REDWOOD BAN
CHAPTER 9: GREENHOUSE GAS EMISSIONS TARGETS AND DEPARTMENTAL ACTION PLANS
CHAPTER 10: TRANSPORTATION OF AGGREGATE MATERIALS
CHAPTER 11: CELL PHONE DISCLOSURE REQUIREMENTS
CHAPTER 12: URBAN FORESTRY COUNCIL
CHAPTER 13: ARSENIC-TREATED WOOD
CHAPTER 14: CONSTRUCTION AND DEMOLITION DEBRIS RECOVERY ORDINANCE*
CHAPTER 15: GREEN BUSINESS PROGRAM
CHAPTER 16: FOOD SERVICE AND PACKAGING WASTE REDUCTION ORDINANCE
CHAPTER 17: PLASTIC BAG REDUCTION ORDINANCE
CHAPTER 18: SOLAR ENERGY INCENTIVE PROGRAM
CHAPTER 19: MANDATORY RECYCLING AND COMPOSTING
CHAPTER 20: EXISTING BUILDINGS ENERGY PERFORMANCE
CHAPTER 21: CLEAN ENERGY FULL DISCLOSURE ORDINANCE
CHAPTER 22: SAFE DRUG DISPOSAL
CHAPTER 23: DRINK TAP ORDINANCE
CHAPTER 24: BOTTLED DRINKING WATER
CHAPTER 25: CLEAN CONSTRUCTION REQUIREMENTS FOR PUBLIC WORKS
CHAPTER 26: BETTER ROOF REQUIREMENTS
CHAPTER 27: ANTIBIOTIC USE IN FOOD ANIMALS
CHAPTER 28: FLAME RETARDANT CHEMICALS IN UPHOLSTERED FURNITURE AND JUVENILE PRODUCTS
CHAPTER 29: ELECTRIC VEHICLE READINESS IMPLEMENTATION*
CHAPTER 30: RENEWABLE ENERGY FOR COMMERCIAL BUILDINGS
CHAPTER 31: ELECTRIC VEHICLE AND CHARGING IN COMMERCIAL PARKING LOTS AND GARAGES*
CHAPTER 32: MANDATORY EDIBLE FOOD RECOVERY
References to Ordinances
San Francisco Fire Code
San Francisco Health Code
HEALTH CODE
THE SAN FRANCISCO CODES
PREFACE TO THE HEALTH CODE
ARTICLE 1: ANIMALS
ARTICLE 1A: ANIMAL SACRIFICE
ARTICLE 1B: PERFORMANCE OF WILD OR EXOTIC ANIMALS FOR PUBLIC ENTERTAINMENT OR AMUSEMENT
ARTICLE 1C: SALE OF ANIMALS
ARTICLE 1D: ANIMAL FUR PRODUCTS
ARTICLE 2: COMMUNICABLE DISEASES
ARTICLE 3: HOSPITALS
ARTICLE 4: DECEASED PERSONS
ARTICLE 5: PUBLIC HEALTH - GENERAL
ARTICLE 6: GARBAGE AND REFUSE
ARTICLE 7: LAUNDRIES
ARTICLE 8: FOOD AND FOOD PRODUCTS
ARTICLE 8A: CANNABIS CONSUMPTION PERMITS
ARTICLE 9: DAIRY AND MILK CODE
ARTICLE 10: MEAT AND MEAT PRODUCTS
ARTICLE 11: NUISANCES
ARTICLE 11A: BED BUG INFESTATION PREVENTION, TREATMENT, DISCLOSURE, AND REPORTING
ARTICLE 11B: HEALTHY BUILDINGS
ARTICLE 12: SANITATION - GENERAL
ARTICLE 12A: BACKFLOW PREVENTION
ARTICLE 12B: SOIL BORING AND WELL REGULATIONS
ARTICLE 12C: ALTERNATE WATER SOURCES FOR NON-POTABLE APPLICATIONS
ARTICLE 14: AMBULANCES AND ROUTINE MEDICAL TRANSPORT VEHICLES
ARTICLE 15: PUBLIC SWIMMING POOLS
ARTICLE 16: REGULATING THE USE OF 'ECONOMIC POISONS'
ARTICLE 17: DISPOSAL OF UNCLAIMED PERSONAL PROPERTY AT SAN FRANCISCO GENERAL HOSPITAL
ARTICLE 18: PROVIDING FOR ISSUANCE OF CITATIONS TO VIOLATORS
ARTICLE 19: SMOKING POLLUTION CONTROL
ARTICLE 19A: REGULATING SMOKING IN EATING ESTABLISHMENTS [SUSPENDED]
ARTICLE 19B: REGULATING SMOKING IN SHARED OFFICE WORKPLACE [SUSPENDED]
ARTICLE 19C: REGULATING SMOKING IN PUBLIC PLACES AND IN HEALTH, EDUCATIONAL AND CHILD CARE FACILITIES [SUSPENDED]
ARTICLE 19D: PROHIBITING CIGARETTE VENDING MACHINES
ARTICLE 19E: PROHIBITING SMOKING IN PLACES OF EMPLOYMENT AND CERTAIN SPORTS ARENAS [SUSPENDED]
ARTICLE 19F: PROHIBITING SMOKING IN ENCLOSED AREAS, CERTAIN UNENCLOSED AREAS, AND SPORTS STADIUMS
ARTICLE 19G: ENFORCEMENT OF SMOKING PROHIBITIONS
ARTICLE 19H: PERMITS FOR THE SALE OF TOBACCO
ARTICLE 19I: PROHIBITING SMOKING IN CITY PARK AND RECREATIONAL AREAS AND FARMERS' MARKETS
ARTICLE 19J: PROHIBITING PHARMACIES FROM SELLING TOBACCO PRODUCTS
ARTICLE 19K: PROHIBITING SALES OF TOBACCO PRODUCTS ON PROPERTY OWNED BY OR UNDER THE CONTROL OF THE CITY AND COUNTY OF SAN FRANCISCO
ARTICLE 19L: PROHIBITING SMOKING AT CERTAIN OUTDOOR EVENTS
ARTICLE 19M: DISCLOSURE TO PROSPECTIVE RESIDENTIAL TENANTS OF WHETHER A UNIT IS SMOKE FREE OR SMOKING OPTIONAL, AND INFORMING EXISTING RESIDENTIAL TENANTS WHERE SMOKING IS OPTIONAL
ARTICLE 19N: ELECTRONIC CIGARETTES - RESTRICTIONS ON SALE AND USE
ARTICLE 19O: [SMOKELESS TOBACCO - USE PROHIBITED AT ATHLETIC VENUES]
ARTICLE 19P: PROHIBITING THE SALE OF TOBACCO PRODUCTS TO PERSONS AGED 18, 19, OR 20
ARTICLE 19Q: PROHIBITING THE SALE OF FLAVORED TOBACCO PRODUCTS
ARTICLE 19R: PROHIBITING THE SALE OF ELECTRONIC CIGARETTES LACKING FOOD AND DRUG ADMINISTRATION PREMARKET APPROVAL
ARTICLE 19S: PROHIBITING THE SALE AND DISTRIBUTION OF TOBACCO PRODUCTS IN SAN FRANCISCO
ARTICLE 20: ALKYL NITRITES
ARTICLE 21: HAZARDOUS MATERIALS
ARTICLE 21A: RISK MANAGEMENT PROGRAM
ARTICLE 22: HAZARDOUS WASTE MANAGEMENT
ARTICLE 22A: ANALYZING SOILS FOR HAZARDOUS WASTE
ARTICLE 22B: CONSTRUCTION DUST CONTROL REQUIREMENTS
ARTICLE 23: VIDEO DISPLAY TERMINAL WORKER SAFETY
ARTICLE 24: CHLOROFLUOROCARBON RECOVERY AND RECYCLING
ARTICLE 25: MEDICAL WASTE GENERATOR REGISTRATION, PERMITTING, INSPECTIONS AND FEES
ARTICLE 26: COMPREHENSIVE ENVIRONMENTAL LEAD POISONING INVESTIGATION, MANAGEMENT AND ENFORCEMENT PROGRAM
ARTICLE 27: HEALTH SERVICE SYSTEM AGREEMENT
ARTICLE 28: MEDICAL CANNABIS USER AND PRIMARY CAREGIVER IDENTIFICATION CARDS
ARTICLE 29: LICENSING AND REGULATION OF MASSAGE PRACTITIONERS AND MASSAGE BUSINESSES
ARTICLE 30: REGULATION OF DIESEL BACKUP GENERATORS
ARTICLE 31: HUNTERS POINT SHIPYARD
ARTICLE 32: DISEASE PREVENTION DEMONSTRATION PROJECT
ARTICLE 33: MEDICAL CANNABIS ACT
ARTICLE 34: HEALTHY PRODUCTS, HEALTHY CHILDREN ORDINANCE
ARTICLE 35: BIOLOGICAL AGENT DETECTORS
ARTICLE 36: CHILD COUGH AND COLD MEDICINE WARNING ORDINANCE
ARTICLE 37: TRANS FAT FREE RESTAURANT PROGRAM ORDINANCE
ARTICLE 38: ENHANCED VENTILATION REQUIRED FOR URBAN INFILL SENSITIVE USE DEVELOPMENTS
ARTICLE 39: COMMERCIAL DOG WALKING
ARTICLE 40: SAFE BODY ART
ARTICLE 41: MENTAL HEALTH
ARTICLE 42: [REPEALED]
ARTICLE 43: SURPLUS MEDICATION REPOSITORY AND DISTRIBUTION
ARTICLE 45: CITY-OPERATED ADULT RESIDENTIAL FACILITY
ARTICLE 46:
ARTICLE 47: ADULT SEX VENUES
ARTICLE 48: REQUIRING RETAIL PHARMACIES TO STOCK OPIOID ANTAGONISTS
ARTICLE 49: SPECIMEN TEST COLLECTION SITES
References to Ordinances
San Francisco Municipal Elections Code
San Francisco Labor and Employment Code
San Francisco Park Code
San Francisco Planning Code
San Francisco Zoning Maps
San Francisco Police Code
POLICE CODE
THE SAN FRANCISCO CODES
PREFACE TO THE POLICE CODE
ARTICLE 1: PUBLIC NUISANCES
ARTICLE 1.1: REGULATING THE USE OF VEHICLES FOR HUMAN HABITATION
ARTICLE 1.2 DISCRIMINATION IN HOUSING AGAINST FAMILIES WITH MINOR CHILDREN
ARTICLE 1.3: TEMPORARY MORATORIUM ON RENTAL INCREASES RENT ROLLBACK BASED UPON APRIL 15, 1979, RENTAL RATES AND REFUNDING ANY RENT INCREASES
ARTICLE 1.5: DISPLAY OF LIFE AND PROPERTY CONSERVATION DECALS
ARTICLE 2: DISORDERLY CONDUCT
ARTICLE 3: GAMES OF CHANCE
ARTICLE 4: PARADES
ARTICLE 4.5: FUNERAL PROCESSION ESCORTS
ARTICLE 5: OFFENSIVE POWDERS
ARTICLE 6: FRAUD AND DECEIT
ARTICLE 7: ANIMALS AND BIRDS
ARTICLE 7.1: HORSE-DRAWN VEHICLES
ARTICLE 8: MINORS
ARTICLE 9: MISCELLANEOUS CONDUCT REGULATIONS
ARTICLE 9.5: PROHIBITING OF PROFESSIONAL STRIKEBREAKERS
ARTICLE 9.6: REGULATIONS FOR SOLICITATION FOR CHARITABLE PURPOSES
ARTICLE 10: REGULATIONS FOR ADVERTISING
ARTICLE 10.1: REGULATING EXPOSURE OF PHOTOGRAPHS, CARTOONS OR DRAWINGS ON NEWSRACKS
ARTICLE 10.2: REGULATION OF COMPUTER RENTAL BUSINESSES
ARTICLE 11: REGULATIONS FOR AMUSEMENTS
ARTICLE 11.1: COMMERCIAL DISPLAY OF DEAD HUMAN BODIES
ARTICLE 11.2: REGULATIONS FOR ADULT THEATERS AND ADULT BOOKSTORES PERMIT AND LICENSE PROVISIONS
ARTICLE 12: REGULATIONS FOR AUTOMOBILES
ARTICLE 13: MISCELLANEOUS REGULATIONS FOR PROFESSIONS AND TRADES
ARTICLE 13.1: JUNK DEALERS - PERMIT AND REGULATION
ARTICLE 13.2 BICYCLE MESSENGER BUSINESSES
ARTICLE 13.3: CAR RENTAL BUSINESSES
ARTICLE 13.4: REDUCING RENTAL-CAR BURGLARIES
ARTICLE 14: LICENSES FOR ADVERTISING
ARTICLE 15: LICENSES FOR AMUSEMENTS
ARTICLE 15.1: ENTERTAINMENT REGULATIONS PERMIT AND LICENSE PROVISIONS
ARTICLE 15.2: ENTERTAINMENT REGULATIONS FOR EXTENDED-HOURS PREMISES
ARTICLE 15.3: PROHIBITING NUDE PERFORMERS, WAITERS AND WAITRESSES
ARTICLE 15.4: ENCOUNTER STUDIOS
ARTICLE 15.5: NUDE MODELS IN PUBLIC PHOTOGRAPHY STUDIOS
ARTICLE 15.6: ESCORT SERVICES
ARTICLE 15.7: EVENT PROMOTERS
ARTICLE 16: REGULATION OF CANNABIS
ARTICLE 17: MISCELLANEOUS LICENSE REGULATIONS
ARTICLE 17.1: REGULATIONS FOR FORTUNETELLING; PERMIT AND LICENSE PROVISIONS
ARTICLE 18: SAN FRANCISCO POLICE PISTOL RANGE
ARTICLE 19: DISPOSAL OF UNCLAIMED PROPERTY
ARTICLE 20: REPRODUCING AND FURNISHING REPORTS
ARTICLE 21: BAN ON PUBLIC USE OF GAS-POWERED LANDSCAPING EQUIPMENT
ARTICLE 22: CITATIONS FOR VIOLATIONS OF CERTAIN PROVISIONS OF THE HEALTH CODE AND POLICE CODE
ARTICLE 23: REGULATIONS FOR PORT AREA*
ARTICLE 24: REGULATING STREET ARTISTS*
ARTICLE 25: REGULATIONS FOR PRIVATE PROTECTION AND SECURITY SERVICES*
ARTICLE 26: REGULATIONS FOR PUBLIC BATH HOUSES
ARTICLE 27: REGULATIONS FOR MORTGAGE MODIFICATION CONSULTANTS
ARTICLE 28: REGULATIONS FOR PAWNBROKERS PERMIT AND LICENSE PROVISIONS
ARTICLE 29: REGULATION OF NOISE
ARTICLE 30: PERMITS FOR TOW CAR DRIVERS
ARTICLE 30.1: PERMITS FOR TOW CAR FIRMS
ARTICLE 31: REGULATIONS FOR TEMPORARY HELIPORTS AND PERMIT PROVISIONS
ARTICLE 32: REGULATIONS FOR CONDUCTING BINGO GAMES
ARTICLE 32A: REGULATIONS FOR CONDUCTING POKER GAMES
ARTICLE 33: PROHIBITING DISCRIMINATION BASED ON RACE, COLOR, ANCESTRY, NATIONAL ORIGIN, PLACE OF BIRTH, SEX, AGE, RELIGION, CREED, DISABILITY, SEXUAL ORIENTATION, GENDER IDENTITY, WEIGHT, OR HEIGHT
ARTICLE 33B: PROHIBITION AGAINST DISCRIMINATION BY CLUBS OR ORGANIZATIONS WHICH ARE NOT DISTINCTLY PRIVATE
ARTICLE 33K: [EXPIRED]
ARTICLE 33L: [EXPIRED]
ARTICLE 33M: [EXPIRED]
ARTICLE 34: REGULATIONS FOR PHOTOGRAPHERS - PERMIT AND LICENSE PROVISIONS
ARTICLE 35: FIREARM STRICT LIABILITY ACT
ARTICLE 36: PROHIBITING THE CARRYING OF A FIREARM WHILE UNDER THE INFLUENCE OF AN ALCOHOLIC BEVERAGE OR DRUG, OR POSSESSION OF A FIREARM WHILE UPON PUBLIC PREMISES SELLING OR SERVING ALCOHOLIC BEVERAGES
ARTICLE 36A: [SALE, MANUFACTURE, AND DISTRIBUTION OF FIREARMS AND AMMUNITION; POSSESSION OF HANDGUNS]
ARTICLE 36B: STORAGE OF FIREARMS IN MOTOR VEHICLES
ARTICLE 36C: PROHIBITION OF FIREARMS AT PUBLIC GATHERINGS
ARTICLE 36D: GUN VIOLENCE RESTRAINING ORDERS
ARTICLE 37: POLICE EMERGENCY ALARM ORDINANCE
ARTICLE 38: PROHIBITING DISCRIMINATION ON THE BASIS OF AIDS AND ASSOCIATED CONDITIONS
ARTICLE 39: PEDICABS
ARTICLE 41: PROHIBITING THE SALE OR POSSESSION OF REPLICA HYPODERMIC NEEDLES OR SYRINGES
ARTICLE 42: SALE AND DISPLAY OF AEROSOL PAINT CONTAINERS AND MARKER PENS
ARTICLE 42A: COLOR TIRES
ARTICLE 42B: MERCURY THERMOMETERS
ARTICLE 42D: SALE AND DISPLAY OF PRODUCTS CONTAINING HYDROFLUORIC ACID
ARTICLE 43: ACCESS TO REPRODUCTIVE HEALTH CARE FACILITIES
ARTICLE 44: CLOSED CAPTIONS ACTIVATION REQUIREMENT ORDINANCE
ARTICLE 45: FIREARMS AND WEAPONS VIOLENCE PREVENTION ORDINANCE
ARTICLE 46: PROHIBITING SELF-SERVICE MERCHANDISING OF TOBACCO PRODUCTS EXCEPT IN PLACES TO WHICH MINORS HAVE NO ACCESS
ARTICLE 47: PERSONAL WATERCRAFT
ARTICLE 48: LASER POINTERS
ARTICLE 49: PROCEDURES FOR CONSIDERING ARRESTS AND CONVICTIONS AND RELATED INFORMATION IN EMPLOYMENT AND HOUSING DECISIONS
ARTICLE 50: CRIMINAL HISTORY IN ADMISSION TO POST-SECONDARY EDUCATIONAL INSTITUTIONS
ARTICLE 51: STORMWATER FLOOD RISK DISCLOSURE
ARTICLE 52: OCCUPANT'S RIGHT TO CHOOSE A COMMUNICATIONS SERVICES PROVIDER
ARTICLE 53: REGULATION OF THIRD-PARTY FOOD DELIVERY SERVICES
ARTICLE 55: ACCEPTANCE OF CASH BY BRICK-AND-MORTAR BUSINESSES
ARTICLE 56: MOTOR VEHICLE STUNT DRIVING
References to Ordinances
San Francisco Port Code
San Francisco Public Works Code
PUBLIC WORKS CODE
THE SAN FRANCISCO CODES
PREFACE TO THE PUBLIC WORKS CODE
ARTICLE 1: GENERAL REQUIREMENTS
ARTICLE 2: PUBLIC CONTRACT PROCEDURE
ARTICLE 2.1: PERMIT FEES AND OCCUPANCY ASSESSMENTS
ARTICLE 2.3: HUNTERS POINT SHIPYARD
ARTICLE 2.4: EXCAVATION IN THE PUBLIC RIGHT-OF-WAY
ARTICLE 3: REGULATIONS IN REGARD TO WORKING CONDITIONS
ARTICLE 4: SEWERS
ARTICLE 4.1: INDUSTRIAL WASTE
ARTICLE 4.2. SEWER SYSTEM MANAGEMENT
ARTICLE 4.3: SEWERS
ARTICLE 5: STREET FLOWER MARKETS
ARTICLE 5.1: ANTI-LITTER RECEPTACLES
ARTICLE 5.2: TABLES AND CHAIRS IN PUBLIC SIDEWALK OR ROADWAY AREAS
ARTICLE 5.3: DISPLAY OF FRUITS AND VEGETABLES OR NONFOOD MERCHANDISE ON PUBLIC SIDEWALKS
ARTICLE 5.4: REGULATION OF NEWSRACKS
ARTICLE 5.5: DISTRIBUTION OF FREE SAMPLE MERCHANDISE ON PUBLIC PROPERTY
ARTICLE 5.6: POSTING OF SIGNS ON CITY-OWNED LAMP POSTS OR UTILITY POLES
ARTICLE 5.7: HANDBILL DISTRIBUTION ON PRIVATE PREMISES; DISPLAY OF BANNERS
ARTICLE 5.8: PERMIT REGULATIONS FOR MOBILE FOOD FACILITIES CONCERNING PRODUCTS FOR HUMAN CONSUMPTION
ARTICLE 5.9: PERMIT REGULATIONS FOR VENDORS
ARTICLE 6: STREET IMPROVEMENT PROCEDURE
ARTICLE 6.1: IMPROVEMENT PROCEDURE CODE
ARTICLE 7: MAINTENANCE DISTRICTS
ARTICLE 9: UNACCEPTED STREETS
ARTICLE 11: SPUR TRACKS
ARTICLE 13: ENGINEERING INSPECTION
ARTICLE 14: UNDERGROUND PIPES, WIRES AND CONDUITS
ARTICLE 15: MISCELLANEOUS
ARTICLE 16: URBAN FORESTRY ORDINANCE
ARTICLE 16.1: TREE DISPUTE RESOLUTION
ARTICLE 17: CONTROL OF DUMPS DISPOSING OF MATERIALS FROM CONSTRUCTION OR DEMOLITION
ARTICLE 18: UTILITY FACILITIES
ARTICLE 19: PUBLIC TELEPHONE BOOTHS ON PUBLIC SIDEWALKS
ARTICLE 20: PROHIBITED BICYCLE ACTIONS AND TRANSACTIONS
ARTICLE 21: RESTRICTION OF USE OF POTABLE WATER FOR SOIL COMPACTION AND DUST CONTROL ACTIVITIES
ARTICLE 22: RECLAIMED WATER USE
ARTICLE 23: GRAFFITI REMOVAL AND ABATEMENT
ARTICLE 24: SHOPPING CARTS
ARTICLE 25: PERSONAL WIRELESS SERVICE FACILITIES
ARTICLE 26*: ILLEGAL DUMPING
ARTICLE 27: SURFACE-MOUNTED FACILITIES
References to Ordinances
San Francisco Subdivision Code
San Francisco Transportation Code
Comprehensive Ordinance List
San Francisco Building Inspection Commission (BIC) Codes
AB-107 Application of Engineering Criteria in SFEBC Chapter 5E
NO. AB-107   :
 
DATE   :
June 27, 2017 (Updated 01/01/2023)
SUBJECT   :
Seismic Strengthening of Soft Story Wood Frame Buildings
TITLE   :
Application of Engineering Criteria in SFEBC Chapter 5E
PURPOSE   :
The purpose of this Bulletin is to establish acceptable design criteria, standards and technical provisions for complying with Chapter 5E of the San Francisco Existing Building Code, as amended by Ordinance 66-13.
REFERENCES   :
Chapter 5E, Current edition of the San Francisco Existing Building Code;
San Francisco Building Code Section 1905
Current edition of the California Existing Building Code, Appendix A - Chapter A4
ASCE 31-03, Seismic Evaluation of Existing Buildings
ASCE 41-06, Seismic Rehabilitation of Existing Buildings
ASCE 41-13, Seismic Evaluation and Retrofit of Existing Buildings
FEMA P-807, Seismic Evaluation and Retrofit of Multi-Unit Wood-Frame Buildings with Weak First Stories
Administrative Bulletin AB-106, Procedures for Implementation of SFEBC Chapter 5E
ABK, 1981, “Methodology for Mitigation of Seismic Hazards in Existing Unreinforced Masonry Buildings: Diaphragm Testing [Topical Report 03],” ABK, A Joint Venture, El Segundo, California, December.
ANSI/AWC 2021 Special Design Provisions for Wind and Seismic
Countryman, D., 1952. “Lateral Tests on Plywood Sheathed Diaphragms [Laboratory Report Number 55],” Douglas Fir Plywood Association, March 28, Information reaffirmed August 1963.
Countryman, D. and Colbenson, P., 1955. “1954 Horizontal Plywood Diaphragm Tests [Laboratory Report 63a],” Douglas Fir Plywood Association, January 25.
NDS 05 Table 11E
SEAOC Blue Book – Seismic Design Recommendations “Anchor Bolts in Light-Frame Construction at Small Edge Distances”
ASTM E488/E488M-22 “Standard Test Methods for Strength of Anchors in Concrete Elements”
DISCUSSION   :
SFEBC Chapter 5E, created with Ordinance 66-13, mandates the seismic retrofit of certain wood-frame residential buildings. Section 506E.2 allows different criteria, or compliance alternatives. Section 506E.4 calls for the development and publication of this Administrative Bulletin to “detail the technical requirements to be used for the evaluation and retrofitting of buildings required to meet the criteria established in Section 506E.2.”
SCOPE   :
This bulletin covers only SFEBC Sections 506E.2 through 506E.4. AB-106 covers administrative and procedural requirements of Chapter 5E. This Bulletin is separate from, but intended to be in coordination with, other sections of Chapter 5E, other Administrative Bulletins, and other forms and instructions.
Part A of this Bulletin applies to all projects seeking to comply with Chapter 5E, regardless of the compliance alternative. Parts B through G apply, respectively, to the specific compliance alternatives allowed in Section 506E.2.
 
DEFINITIONS: In addition to the definitions in Section 503E, the following definitions shall apply for purposes of this Bulletin:
TARGET STORY. Any story above grade plane, or any basement or underfloor space that extends above grade at any point, in which the wall layout or plan configuration is substantially different from the wall layout or plan configuration in the story above, except that a story is not a Target Story if it is the topmost story or if the difference in configuration is primarily due to the story above being a penthouse, an attic with a pitched roof, or a setback story.
 
Commentary: This definition is taken from the Screening Form Instructions developed to implement Section 506E.2, but it has been modified to clarify that the consideration of “substantially different” wall layout or configuration applies to basements and underfloor areas as well as to stories above grade plane. As discussed in the Screening Form Instructions, “substantially different from” generally means “substantially weaker than” and can be a matter of engineering judgment, to be decided as part of the Screening Form approval process. As described in the Screening Form and Screening Form Instructions, Chapter 5E applies only to wood-frame target stories, that is, target stories in which the seismic force-resisting system in any direction relies on wood-frame wall elements. A building can have more than one target story.
Part A. GENERAL REQUIREMENTS
A1. Compliance
A1.1. Required scope of evaluation and/or retrofit. Evaluation and/or retrofit shall address:
   1.   Vertical elements of the seismic force-resisting system (SFRS) in each target story in which the existing SFRS relies on wood-frame elements, and
   2.   Each floor diaphragm immediately above such a target story, and
   3.   Elements of the seismic force-resisting load path from each such diaphragm through the foundation.
Exception: Where the existing vertical elements of the SFRS are shown to comply by evaluation, the diaphragm immediately above each target story need to be evaluated.
A.1.1.1. Floor diaphragm evaluation and/or retrofit. Floor diaphragms subject to evaluation and/or retrofit shall be shown to have adequate strength at the following locations:
   1.   For straight lumber sheathed diaphragms without integral hardwood flooring: Throughout the diaphragm. At the discretion of the code official, this requirement may be waived where the condition occurs only in relatively small portions of each dwelling unit.
   2.   For other diaphragms: At locations where forces are transferred between the diaphragm and a new or strengthened vertical of the SFRS. Collector elements may be provided to distribute the transferred force over a greater force over a greater length of diaphragm.
 
Commentary: Evaluation of the diaphragm’s adequacy is only required when new vertical elements are added to the target story or existing vertical elements in the target story are strengthened. This allowance is considered appropriate for the limited objective of Chapter 5E. Therefore diaphragm adequacy need only be confirmed in two cases.
Case 1. Straight lumber sheathed diaphragms without integral hardwood flooring are thought to be considerably weaker and more flexible than other diaphragm systems. Though there are no known collapses due to this condition, expected poor performance could compromise the building’s ability to meet even the limited objective of Chapter 5E. Integral hardwood flooring - but not newer “floating” wood flooring - provides significant added strength and stiffness. Even in buildings with original hardwood flooring, some remodeled, carpeted, or tiled areas might have had the original wood flooring removed. Areas of the diaphragm that form a roof for the target story (such as the portion of a garage that extends beyond the wall line above, or at a lightwell or building setback) are also unlikely to have hardwood flooring to supplement the straight sheathing. These areas should be identified as part of the condition assessment (see Section A3) and evaluated. Small isolated areas without hardwood flooring are not expected to affect overall building performance, so the provision grants a waiver for these cases. As a rule of thumb, an area up to 150 square feet per unit might represent such an acceptable condition.
Case 2. Where vertical SFRS elements are added or strengthened, an adequate load path and diaphragm must be provided. This provision requires a local check for each such element but does not require an overall analysis of the full diaphragm. The unit shear demand at each vertical element is calculated as the force in the element divided by the length of the element plus any collector. The shear demand is then compared to the unit shear capacity of the diaphragm. Where demand is greater than capacity, either the diaphragm is strengthened or the collector is lengthened. An existing diaphragm can be strengthened by adding a wood structural panel soffit attached to the bottom of the floor joists in the vicinity of the vertical SFRS element. The rules given in Section B5.1.1.2 may be useful for combining the capacities of new and existing diaphragm components. Diaphragm capacity need not be checked at existing vertical elements that are not strengthened because (except for Case 1) it is assumed that the unit capacities of the existing vertical elements and the diaphragm are comparable.
A1.2. Other SFEBC requirements and Administrative Bulletins. Alterations and repairs required to meet the provisions of Chapter 5E shall comply with all other applicable structural requirements of the SFEBC unless specifically waived by those requirements, by this Bulletin, or by related Administrative Bulletins.
 
Commentary: See Administrative Bulletin 106 regarding procedural compliance with SFEBC Chapter 5E, specifically Section 506E.6.
A1.3. Qualified historic buildings. In addition to or in place of the criteria allowed by SFEBC Section 506E.2, qualified historical buildings shall be permitted to use structural engineering criteria provided in the latest edition of the California Historical Building Code (California Code of Regulations Title 24 Part 8), subject to the eligibility requirements of that code.
 
Commentary: SFEBC Section 504E.5 also mentions the CHBC, but that provision is about historic preservation in accord with San Francisco Planning Department guidelines and has no direct bearing on the structural engineering criteria.
A2. Seismicity, Soil, and Geotechnical issues
A2.1. Site Class E. Buildings located in areas labeled “NEHRP E” on the latest USGS map of “Soil Type and Shaking Hazard in the San Francisco Bay Area” will be assigned to Site Class E unless site-specific investigation in accordance with ASCE 7-16 Chapter 20 indicates otherwise.
A2.2. Site Class F. The requirement in ASCE 7-16 Section 11.4.8 for site response analysis of Site Class F sites is waived, such sites should be considered as Site Class E.
 
Commentary: SFEBC Chapter 5E does not require mitigation of existing geologic site hazards such as liquefiable soil. Also, many buildings subject to Chapter 5E would be exempt from site response analysis by the exception to ASCE 7-16 Section 20.3.1.
A2.3. Seismic ground motion values. Where seismic ground motion values are calculated per ASCE 7-16 Section 11.4 or by similar provisions, the value of Fa shall be taken as 1.3 for Site Class E.
 
Commentary: This requirement applies to any code-based procedure for calculating seismicity parameters, such as that used by CEBC Appendix A - Chapter A4 and application of “regular code” provisions through the California Historical Building Code. It also applies where criteria such as ASCE 31, ASCE 41, and FEMA P-807 apply equations similar to those in ASCE 7 Section 11.4. When using the USGS ground motion application, engineers are cautioned to confirm use of the correct value Fa as described above.
A3. Assessment of Existing Building Conditions
A3.1. Building investigation and report. In support of an engineering evaluation or retrofit design, the owner shall conduct or cause to be conducted an investigation of the existing building. The engineer of record shall prepare a written report documenting procedures, findings, and conclusions of the investigation. The report may reference other materials submitted to demonstrate compliance or to support findings and conclusions.
A3.1.1. Scope of investigation. At minimum, the investigation shall comply with any investigation and assessment provisions in the engineering criteria selected from SFEBC Section 506E.2, as modified by subsequent Parts of this Bulletin. Otherwise, the investigation scope and methods may generally be set at the discretion of the engineer of record, but all findings shall be reported. The Department is authorized to require additional investigation as needed to fulfill the purpose of the report and the intent of SFEBC Chapter 5E. With the approval of the Department, field verification of assumed conditions may be performed during the construction phase.
As needed or required, the investigation shall include identification, verification, and assessment of existing conditions relevant to the engineering assumptions applied in the evaluation or retrofit design. The investigation shall be based on a combination of non-destructive testing or inspection, destructive testing or inspection, and reference to record documents. Where record documents are used to reduce the scope of testing or other on-site work, appropriate field verification is required.
 
Commentary: With respect to evaluation, the primary purpose of the investigation is to identify or confirm the nature of the existing construction as needed to justify load drift curves, tributary floor weights, load path assumptions, etc. A secondary purpose is to provide condition assessment sufficient to rule out deterioration or construction defects significant enough to affect earthquake performance of the structure as a whole. The investigation should therefore seek evidence of damage, deterioration, or defective construction sufficient to affect significantly the performance of the seismic force-resisting system. With respect to retrofit design, the primary purpose of the investigation is to confirm design assumptions regarding the adequacy of existing seismic load path components within the context of the retrofitted structure. In addition, though it need not be stated in the provision, the Department is always authorized to require repair of damage, correction of defects, and elimination of dangerous conditions; hence the requirement that “all findings shall be reported.”
A3.1.2. Timing of investigation. Unless otherwise required by the engineering criteria selected from SFEBC Section 506E.2, as modified by subsequent Parts of this Bulletin, with the approval of the Department, investigation may be deferred to a confirmation or construction phase. The deferred investigation shall be specified as a special inspection item in accordance with SFBC Chapter 17.
 
Commentary: This allowance is offered for the benefit of owners for cases in which destructive investigation will be unusually disruptive or expensive. However, the owner will bear the risk of change orders, design revisions, and supplemental design review if actual conditions differ from those assumed by the evaluation or design. Approval of the Department is required to allow the Department to identify cases where deferred investigation will complicate its review and approval process. The Department may allow some parts of the investigation to be delayed while requiring other parts of the investigation to be completed prior to review of calculations.
A3.2. Existing materials and components. Where the applicable engineering criteria specify material or structural properties of existing elements, those criteria shall be used. Otherwise, the general rules of this section apply.
A3.2.1. Damage and defects. The capacity of any element damaged by deterioration, wear, or other causes or constructed or altered so as to differ from its intended condition shall be reduced based on the judgment of the engineer of record, subject to review of condition assessment findings and the approval of the Department. This provision shall apply where the applicable engineering criteria do not make an explicit provision for capacity reduction.
 
Commentary: This provision is consistent with ASCE 31-03 Section 4.2.4.4.
A3.2.2. Relation of nominal and expected strength to allowable stress. Where element capacities are based on allowable stresses from codes and standards, nominal strengths shall be taken no greater than the allowable stresses multiplied by the following factors: 1.7 for steel; 2.5 for masonry; 2.0 for wood. Where the element is ductile or deformation-controlled, the expected strength shall be taken as 1.25 times the nominal strength.
 
Commentary: This provision is consistent with ASCE 31-03 Section 4.2.4.4.
A3.2.3. Concrete footings and stem walls. Evaluation and design of existing concrete footings shall be permitted to assume default concrete strength based on ASCE 41-13.
A3.2.4. Unreinforced brick footings. The capacity of an existing brick footing to resist shear or pullout of an existing or new anchor shall be established by testing or by reference to approved tests of similar conditions. Where the capacity of an anchor is limited by failure of the footing or grout, the anchored wall or frame element shall be considered non-ductile or force-controlled.
 
Commentary: Because FEMA P-807 presumes ductile retrofit elements, the last sentence of this provision means that retrofit elements designed with FEMA P-807 may only be used with brick footings when testing has demonstrated that the anchor will develop the strength of the wall or frame element or will yield itself in a ductile fashion.
A3.2.5. Concrete or masonry retaining walls.
Reserved.
A3.2.6. Sheathed wood-frame walls and partitions. Wood-frame walls and partitions shall be permitted to use peak strength values from Bulletin Section B5.1.1. Where these values are used, they shall be taken as expected strengths and reduced to nominal strength per Bulletin Section A3.2.2 where used on non-ductile or force-controlled elements. This provision is subject to the following limitations:
1.   A wall assembly may be considered deformation-controlled if all sheathing materials that are individually force-controlled are ignored in the strength calculation.
2.   Retrofit designs based on R values from the building code shall use only code-approved sheathing materials and combinations appropriate to the assumed R value.
A3.2.7. Anchorage of sill plates.
Sill plates of all walls that are considered to resist seismic shear forces shall be anchored to the foundation, structural slab or stem walls that they rest on. Total shear capacity of competent existing bolts and any added anchor bolts shall be adequate to resist the shear demand on the wall. Anchors in walls that are not considered to resist seismic shear forces are not required to be investigated.
When investigation confirms the presence of concrete foundations supporting 2x or 3x sill plates anchored with ½" to ¾" diameter bolts with washers and nuts, it is acceptable to determine in-plane shear capacities in accordance with applicable tables in ANSI/AWC National Design Specification, provided that the supporting concrete is sound, sill plates are in good condition, anchor bolts do not show extensive corrosion, and anchors are located in the concrete per SFBC Section 1905.
The capacity of existing sill plate anchors in brick footings or stem walls shall be established per Section A3.2.4.
Maximum spacing between existing sill plate anchor bolts shall be six (6) feet for walls with plywood sheathing and ten (10) feet for other shear walls (archaic walls). There shall be a minimum of two (2) shear anchors per each wall segment that is considered to resist seismic forces.
All anchors for which capacity cannot be determined by calculation, or for which capacities are not published in an approved Standard, may have capacities established by testing. Anchor bolts that are placed out of plumb, are loose, show extensive signs of corrosion, or are otherwise damaged shall not be considered to provide lateral load resistance.
Where new anchors are required, strength, spacing and installation requirements shall be determined in accordance with the SFBC.
 
Commentary: Reliable performance of a lateral load resisting system depends on the presence of a complete load path, from floor diaphragm through the lateral load resisting elements and their foundation, to the supporting soils. Absence of an adequate connection between the wood sill and foundation is a gap in the load path that limits the ability of the shear wall to resist seismic forces.
A3.2.8. Default strength values for diaphragms. Default values for evaluation and retrofit design of existing or strengthened diaphragms may be taken from ASCE 41-13 Table 12-2 or 15-2 when using ASCE 31 or ASCE 41, or from SDPWS-08 Tables 4.2A through 4.2D (AF&PA, 2009) when using CEBC Appendix A- Chapter A4, with adjustments for nominal v. expected strength, ASD, or LRFD. When using FEMA P-807, diaphragm strength may be determined using the nominal strength from ASCE 41 or SDPWS multiplied by phi = 1.0, or peak expected strength as provided in Table A3.2.8.
Table A3.2.8 Peak Expected Strength of Existing or Strengthened Horizontal Diaphragms for use with FEMA P-807.
 
Diaphragm Description
Peak Expected Strength (plf)
Unblocked wood structural panel with thickness 3/8 in. or greater, any case1
730
Unblocked wood structural panel with thickness ½ in. or greater, Case 11 with 8d common nails
1380
Blocked wood structural panel with thickness 15/32 in. or greater and 8d nails, any case1
1380
Blocked wood structural panel with thickness 15/32 in. or greater and 10d nails @ 4/6/12 or better, any case1
1710
Diagonal wood sheathing with directly applied built-up roofing (derived from ABK Topical Report 03)
860
1 Case refers to load case diagrams in SDPWS Table 4.2A
 
Commentary: This section identifies sources of diaphragm capacities suitable where Chapter 5E requires diaphragm evaluation or strengthening. Table A3.2.8-1 is for use only with procedures like FEMA P-807 in which capacities are based on estimated peak strength. Because FEMA P-807 is based on the estimated peak strength of vertical elements, the diaphragm strength is allowed to be derived on a similar bases, with a phi factor of 1.0. Expected strengths in Table A3.2.8-8 are based on test information from APA (Countryman, 1952; Countryman and Colbenson, 1955) and ABK (1981). Reference to SDPWS in the table is only for load case diagrams; expected strengths are to be taken from the table.
A4. Structural Calculations and Project Documentation
A4.1. Submittals. Structural calculations and supporting documents shall be prepared and submitted as required by Bulletin Section A4.2. Other documents shall be prepared and submitted as required by Administrative Bulletin 106.
A4.2. Structural calculations and supporting documents. Structural calculations shall be submitted as required to confirm compliance with the selected engineering criteria. Calculations shall be specific to the engineering criteria used and shall include, at minimum:
1.   A statement that the evaluation or retrofit design was prepared to demonstrate compliance with SFEBC Chapter 5E.
2.   Identification of the engineering criteria used for the evaluation or retrofit design, including the performance objective used with FEMA P-807, ASCE 41-06, or ASCE 41-13.
3.   All building investigation, soils, geotechnical, or other supporting reports, as well as a summary of such reports indicating how the findings or conclusions are reflected in the structural calculations.
4.   Identification of structural properties and capacities assumed for all existing materials and elements, including any capacity reductions for damage, deterioration, or defect.
5.   Identification of structural properties and capacities assumed for all new materials and elements, including product literature for proprietary devices.
6.   If requested by the Department, verification calculations for any engineering software used.
7.   Other information as required by the Department.
A5. Construction Quality Assurance
A5.1. Testing and inspection. All work shall comply with inspection and testing requirements of the building code as they apply to existing buildings and structures. Additional field verification, structural observation, testing, and inspection may be required in accordance with the selected engineering criteria or as directed by the Department.
A6.1. Use of Steel Special Moment Frames. Special Steel Moment Frames shall comply with all applicable provisions of AISC 341-10, including but not limited to connection design and lateral bracing of beams.
Exception: The “strong-column/weak-beam” provision of AISC 341-16, Section E3.4a is waived, provided that the columns carry no gravity load.
It is permitted to employ approved commercially available proprietary frame systems to achieve the Special Moment Frame classification.
A6.2. Use of Steel Ordinary Moment Frames or Steel Intermediate Moment Frames. CEBC Appendix A - Chapter A4 allows the use of any seismic force resisting system permitted in the building code, when the applicable R factor is employed. The building code (through reference to ASCE7) permits the use of steel moment frames other than Steel Special Moment Frames in light frame construction only when specific limitations regarding the building height and unit weights of floors and walls are met. These limitations are waived for buildings with no more than three stories above the highest Target Story. The R, Ω0, and Cd factors employed shall be those applicable to the selected system.
A6.3. Use of Cantilevered Column Systems. Cantilevered column systems conforming to the following provisions may be considered as moment frame systems (Special, Intermediate, or Ordinary, as applicable, based on detailing) with regard to determination of the R, Ω0, and Cd factors.
1.   Columns shall not carry gravity load.
2.   Columns shall be configured in pairs (or larger groups) connected by a continuous foundation or grade beam.
3.   The continuous foundation or grade beam shall be designed to resist the expected plastic moment at the base of each column, computed as RyFyZ, as defined in AISC 341-16.
4.   The flexibility of the continuous foundation or grade beam, considering cracked section properties of reinforced concrete, shall be included in computing the deformation of the cantilevered column system.
5.   Cantilevered columns shall be considered as twice their actual height when checking lateral torsional buckling.
Part B. APPLICATION OF FEMA P-807 TO EVALUATION AND RETROFIT DESIGN
 
DISCUSSION:
FEMA P-807, unlike the other documents cited by Section 506E.2, is not a code or standard and is written in a guideline or narrative style. Enforceable provisions in “code language” are therefore provided here, adapted from FEMA P-807 Appendix B. In general, use of FEMA P-807 for compliance with SFEBC Chapter 5E shall mean compliance with the code language provisions in this Bulletin; FEMA P-807 itself constitutes a commentary to these provisions.
B1. Compliance
B1.1. Performance Objective
B1.1.1. Hazard level. The spectral demand shall be 0.5SMS, calculated in accordance with ASCE 7-16 Section 11.4 except that for sites in Site Class E, the value of Fa shall be taken as 1.3.
 
Commentary: The value of Fa is modified for Site Class E to adjust the demand for site effects not considered explicitly in the development of FEMA P-807 (see FEMA P-807 section 2.6.1).
B1.1.2. Performance level. Acceptable performance shall be based on drifts corresponding to the Onset of Strength Loss in the seismic force-resisting wood-frame elements.
 
Commentary: This provision merely reflects the requirements of the ordinance, referencing the Onset of Strength Loss performance level defined in FEMA P-807. It does not require any additional work by the engineer, since the Onset of Strength Loss criteria are already embedded in the criteria given in this Bulletin.
B1.1.3. Maximum drift limit probability of exceedance. The maximum drift limit POE for evaluation or retrofit design shall be 30 percent.
Exception: Where the story or underfloor area subject to evaluation or retrofit contains only parking, storage, or utility uses or occupancies, the maximum drift limit POE for evaluation or for retrofit design shall be 50 percent, as long as the additional requirements of Bulletin Section B7.3 are met.
 
Commentary: This Exception incorporates the alternative criteria given in SFEBC Section 506E.3. The alternative criteria apply to what FEMA P-807 calls “optimized retrofit,” as discussed in FEMA P-807 Sections 6.3.1 and 6.4.2.
B1.2. Required scope of work. Compliance with the provisions of SFEBC Chapter 5E using FEMA P-807 requires:
1.   Correction of all aspects of eligibility non-compliance per Bulletin Section B3, and
2.   Correction of all building survey non-compliance per Bulletin Section B4, and either
3a.   Demonstration of an acceptable existing condition per Bulletin Section B6, or
Where retrofit is required but the provisions of Bulletin Section B7 cannot be satisfied, the building shall be considered ineligible for compliance with SFEBC Chapter 5E using FEMA P-807.
B2. Definitions
 
Commentary: In some instances, the notation and terminology differ slightly from those in FEMA P-807 Chapters 1-7.
B2.1. Terminology. Terms used in Bulletin Part B shall have the meanings provided here. Terms not defined here shall have the meanings provided in the building code.
CENTER OF STRENGTH. At each story, the location in plan that represents the weighted average location of the load in all wall lines, at the drift associated with the story strength.
DRIFT. For a given story, the calculated or postulated lateral deflection within that story divided by the story height, normally expressed as a percentage.
FIRST STORY. Any target story subject to SFEBC Chapter 5E .
LOAD-DRIFT CURVE. For a wall assembly, wall line, or story, the relationship characterizing the variation of shear resistance versus drift, for the full range of relevant drifts. For a wall assembly, the load value is given in units of force per unit length. For wall lines and stories, the load value is given in units of force.
LOAD-ROTATION CURVE. For a story, the relationship characterizing the variation of torsional resistance versus story rotation, for the full range of relevant rotations, given in units of torque as a function of rotation angle.
PROBABILITY OF EXCEEDANCE (POE). The desired or calculated probability that the structure will respond beyond the drift limits representing the desired performance level, in at least one direction, when subjected to a specified hazard level. Within SFEBC Chapter 5E and this Bulletin, POE means the probability of exceeding the drift limits associated with Onset of Strength Loss.
 
Commentary: As used in SFEBC Chapter 5E and this Bulletin, POE is identical to what FEMA P-807 Chapters 1 through 7 typically call “drift limit POE.”
QUALIFYING WALL LINE. For purposes of checking eligibility of floor or roof diaphragms, a wall line that contributes substantially to the peak story strength and has an adequate load path connecting it to the diaphragms it affects.
 
Commentary: See FEMA P-807 Section 2.6.4 for discussion of rules for “qualifying” wall lines. The definition is subject to the judgment of the engineer of record and the Department.
SPECTRAL CAPACITY. For a given POE, the highest level of spectral acceleration a structure can sustain without responding beyond the drift limits representing the desired performance level, given as a multiple of the acceleration of gravity, and calculated separately in each principal direction.
SPECTRAL DEMAND. See Bulletin Section B1.1.1. The spectral demand is given as a multiple of the acceleration of gravity.
STORY. For purposes of applying engineering criteria in SFEBC Section 506E and this Bulletin, see the building code definition and this Bulletin’s definition of First Story. The definition in SFEBC Section 503E applies only to the counting of stories for determining scope per SFEBC Section 502E.
STORY STRENGTH. The maximum load value from the story load-drift curve, calculated separately in each principal direction.
STORY STRENGTH, BASE-NORMALIZED. The story strength divided by the total seismic weight of the building.
STORY STRENGTH, STORY-NORMALIZED. The story strength divided by the sum of the tributary floor weights of all the floors above the story in question.
STORY TORSIONAL STRENGTH. The maximum torsional resistance value from the story load-rotation curve.
STRENGTH DEGRADATION RATIO. In each direction, a value between 0.0 and 1.0 calculated as the first story strength divided by the load corresponding to a drift of 3 percent from the first story load-drift curve.
TORSION COEFFICIENT. A value that need not be taken greater than 1.4, calculated as the first story torsional demand divided by the first story torsional strength.
TORSIONAL ECCENTRICITY. The absolute value of the plan distance, in x and y components, between the second story center of strength and the first story center of strength.
TRIBUTARY FLOOR WEIGHT. The total seismically active weight tributary to a single floor level comprising dead load and applicable live load, snow weight, and other loads as required by the building code.
UPPER STORY. Any story above the first story.
WALL ASSEMBLY. A unique combination of sheathing materials over wood-stud framing.
WALL LINE. A collection of full-height and partial-height wall segments or frames within a single story that satisfies the rules in Bulletin Section B5.1.2.
 
Commentary: A wood-frame wall line is generally assumed to contribute strength only in the direction parallel to its length. A wall line expected to contribute strength in a direction other than parallel to its length, such as a cantilever column or fixed-based moment frame, must be modeled appropriately.
WALL SEGMENT. A portion of wood-frame wall made from a single wall assembly. For purposes of this definition, any sheathed run of wood-stud framing that could contribute to a story’s lateral strength or stiffness shall be considered a potential wall segment, whether or not the framing and sheathing were intentionally designed, detailed, sized, or located to contribute that strength or stiffness.
B2.2. Notation
AU   The base-normalized upper-story strength, calculated separately for each direction.
AW   The weak-story ratio, calculated separately for each direction.
CD   The strength degradation ratio, calculated separately for each direction.
CT   The torsion coefficient.
CU   The minimum of the story-normalized story strengths of any of the upper stories, calculated separately for each direction.
 
Commentary: Where the story strength is roughly constant for all upper stories, CU will generally be the story-normalized strength of the second story.
COSi   The plan location, in x and y coordinates, of the center of strength of story i.
ex, ey   The x and y components, respectively, of the torsional eccentricity.
fw   The load-drift curve for wall line w.
Fi   The load-drift curve for story i, calculated separately for each direction.
hw   The floor-to-ceiling height of wall line w.
H1   The floor-to-ceiling height of the tallest first story wall line, determined separately in each direction.
I   A subscript index indicating floor or story. Story i is between floor i and floor i+1.
Lw   The length of wall line w, taken as the longest possible length of wall that satisfies the rules in Bulletin Section B5.1.2, including the length of any openings within it.
Lx   The overall building dimension in the x direction.
Ly   The overall building dimension in the y direction.
POE   Probability of Exceedance
Qopen   The adjustment factor for openings in a wall line.
Qot   The adjustment factor for overturning of a wall line.
Qs   The story height factor for the first story, calculated separately for each principal direction.
Sc   The spectral capacity, calculated separately for each direction.
Sd   The spectral demand.
ti   The load-rotation curve for story i.
Ti   The story torsional strength of story i.
V1r   The story strength of the retrofitted first story, calculated separately for each direction.
Vi   The story strength of story i, calculated separately for each direction.
VU   The story strength of the upper story that determines the value of CU.
 
Commentary: Where the story strength is roughly constant for all upper stories, VU will generally be the second story strength.
w   A subscript index indicating a single wall line.
W   The total seismic weight of the building, equal to the sum of all the tributary floor weights.
Wi   The tributary floor weight of floor i.
WSP   Wood structural panel
x   A subscript index indicating one of two principal directions.
αPOE,0   The POE adjustment factor for a CD value of 0.0.
αPOE,1   The POE adjustment factor for a CD value of 1.0.
δj   Drifts at which load-drift curves are characterized. See Table B5.1.1.
Δi   In each direction, the drift at which the story strength of story i occurs.
J1   The first story torsional demand.
B3. Eligibility
B3.1. General. Buildings that do not comply with the requirements of Bulletin Section B3 shall be considered ineligible for compliance using FEMA P-807.
Exception: Buildings in which all aspects of non-compliance will be eliminated through alteration or retrofit are eligible for compliance using FEMA P-807.
B3.2. Massing
1.   The building has no more than four stories above grade plane at any point around its perimeter.
2.   The building’s wood-framed stories are not supported by an above-grade podium structure.
 
Commentary: Item 1 relies on the building code’s definition of story above grade plane. Item 2 is referring to a concrete podium structure generally extending at least one story above grade and topped by a concrete diaphragm that provides a base for wood framing above. Item 2 is not intended to rule out concrete foundation elements or stem walls that extend above grade.
B3.3. Upper stories
1.   The upper-story seismic force-resisting systems are bearing wall or building frame systems of wood-frame walls with shear panels.
2.   The upper-story floor-to-floor heights are between 8 feet and 12 feet and are constant within each story.
3.   In each upper story, in each principal direction, the distance from the center of strength to the center of mass of the floor below it is no more than 25 percent of the corresponding building dimension.
 
Commentary: The intent of this approximate rule is to ensure that no upper story is prone to significant torsion, and that inertial forces from upper stories should transfer to the first story near the geometric center of the second floor. See FEMA P-807 Section 2.6.2.
4.   No upper story or floor above an upper story has a weight irregularity as defined by ASCE/SEI 7-16 Table 12.3-2, Type 2.
5.   No upper story has a vertical geometric irregularity as defined by ASCE/SEI 7-16 Table 12.3-2, Type 3.
B3.4. First story, basement and foundation
1.   The first story height may vary, but the maximum first story height, from top of foundation to top of second floor framing is between 8 feet and 15 feet.
2.   The first story seismic force-resisting systems are bearing wall or building frame systems of wood-frame walls with shear panels or combine such systems with steel moment-resisting frame systems, steel cantilever column systems, or steel buckling-restrained braced frame systems.
 
Commentary: FEMA P-807 is not suitable for evaluating or designing concentrically braced frames, concrete shear walls, or reinforced masonry shear walls. See FEMA P-807 Section 6.5. If these systems exist or are proposed for as retrofit elements, compliance must be demonstrated using one of the other methods allowed by SFEBC Section 506E.2.
3.   The first story includes no full-height concrete or masonry walls.
 
Commentary: Buildings with full-height concrete or masonry walls at the full perimeter of the story of interest are expected to be exempt from SFEBC Chapter 5E. Buildings with a combination of full-height concrete or masonry walls and other systems (wood-frame walls, steel moment frames, etc.) might be required to comply with SFEBC Chapter 5E but will not be able to use FEMA P-807 to demonstrate compliance.
4.   The first story walls and frames have continuous concrete footings or concrete slab-on-grade foundations. If some or all of the first floor is raised over a crawl space, the crawl space has concrete stem walls to the underside of the first floor framing.
 
Commentary: Concrete stem walls are considered to provide a base similar to a concrete foundation. Wood-framed cripple walls, whether braced or unbraced by sheathing of any type, are not adequate to meet this provision.
5.   First story walls and frames may be partial height over a concrete or reinforced masonry retaining wall or foundation stem wall, but any partial-height wall or frame is at least four feet tall from top of stem wall to underside of second floor framing.
6.   If the building has a basement, the basement walls and the floor diaphragm just above them are capable of transferring seismic forces between the foundation and the first story, and the basement story is laterally stronger than the first story above it.
B3.5. Floor and roof diaphragms. Floor and roof diaphragms shall satisfy the eligibility requirements of this subsection.
Exception: Diaphragms shown to have no deficiencies or irregularities that would prevent development of the strength of any seismic force-resisting wall or frame or would otherwise control the overall seismic response of the structure need not satisfy the eligibility requirements in this subsection.
 
Commentary: The intent of these approximate rules for diaphragms is to ensure that the structure does not develop a premature mechanism or failure mode. See FEMA P-807 Section 2.6.4 for additional explanation and guidance.
1.   No portion of the second floor diaphragm between qualifying wall lines has an aspect ratio greater than 2:1.
2.   The second floor diaphragm does not cantilever more than 25 feet from a qualifying wall line.
3.   If the second floor diaphragm cantilevers more than 10 feet from a qualifying wall line, diaphragm chords are adequate to develop the lesser of the strength of the diaphragm or the diaphragm forces associated with the peak strength of the qualifying wall line.
4.   No floor or roof diaphragm has a reentrant corner irregularity in which either projecting leg of the diaphragm beyond the reentrant corner is longer than 15 percent of the corresponding plan dimension of the building, unless each leg of the diaphragm satisfies the aspect ratio and cantilever rules of this subsection.
 
Commentary: This provision differs from the irregularity defined in ASCE/SEI 31-03 or as Type 2 in ASCE/SEI 7-16 Table 12.3-1 in order to limit diaphragm demands. See FEMA P-807 Section 2.6.4.
5.   No floor or roof diaphragm has a vertical offset unless load path components are present and adequate to develop the diaphragm strength across the offset.
6.   No floor or roof diaphragm has cutouts or openings within it such that, along any line across the diaphragm, the sum of the opening widths along that line is more than 25 percent of the overall diaphragm dimension along that line.
B4. Building Survey
B4.1. General. Structural components shall be investigated in accordance with Bulletin Section B4 as needed to confirm eligibility per Bulletin Section B3 and to support structure characterization per Bulletin Section B5, evaluation per Bulletin Section B6, and retrofit design per Bulletin Section B7.
B4.2. Wall framing and sheathing. The investigation shall determine the length and location in plan of all wall segments and wall lines in all stories as needed to calculate load-drift curves.
The investigation shall determine the size and location of openings in each wall line as needed to calculate adjustment factors for openings and adjustment factors for overturning.
The investigation shall determine all unique frames or wall assemblies in the first story and representative wall assemblies in the upper stories. Where sheathing includes wood structural panels or where sheathing load-drift data is a function of nailing, the investigation shall also determine the nail size and edge nail spacing. Panel edge nailing shall be investigated over at least five nail spaces and as needed to confirm a reliable spacing assumption.
 
Commentary: Unless building-specific conditions indicate a need for more extensive investigation, the minimum recommended investigation should include one location of each distinct wall assembly in the first story and in any upper story, but not less than one perimeter and one interior wall line in the first story and in any upper story. If prior investigation reports based on destructive investigation are available, they may be relied on. If original drawings are available, they may be relied on to reduce the scope of investigation, but some investigation is still necessary to confirm the reliability of the drawings.
B4.3. Floor and roof framing and diaphragm. The investigation shall determine the construction of floor and roof framing and diaphragm sheathing, including the direction of framing and the mechanism of gravity load transfer, as needed for calculation of adjustment factors for overturning. The second floor shall be investigated. Subject to approval of the Department, the roof and upper floors need not be investigated in detail where there is evidence that their relevant attributes are similar to those of the second floor.
B4.4. Load path components. The investigation shall determine the nature of the load path components and connections for transfer of forces between diaphragms and walls or frames as needed to confirm that the wall line will participate in resisting drift.
 
Commentary: For non-WSP sheathing, the intent is to confirm that fastening reasonably conforms to conventional construction requirements. For existing WSP shear walls with nail spacing closer than six inches, it should be confirmed at representative locations that shear wall top and bottom connection capacity is appropriate to the sheathing capacity.
The investigation shall determine the presence or absence of hold-down hardware at the base of all first story walls, as well as the adequacy of installation of representative types at representative locations.
The investigation shall confirm that anchors are provided at the base of the first story walls.
Table B4.4 shows where the load path may be assumed adequate or is subject to investigation or confirmation. Table B4.4 applies only to walls whose strength is counted in the analysis. For any condition subject to investigation, the load path may be assumed lacking, and the corresponding wall strength may be ignored, but only if assumed so consistently throughout the building.
 
Commentary: The load path may be assumed lacking, but not selectively so as to “correct” torsion or other irregularities. This provision is similar to ASCE 31 and ASCE 41 limits on the designation of secondary components.
Exception: Wherever the strength of two stories is being compared, an adequate load path must be assumed for all walls and partitions in the upper story.
 
Commentary: The exception prevents underestimating the upper story strength. The exception will apply for calculations of weak story or soft story ratio in ASCE 31/41, CEBC Appendix A - Chapter A4, and other code-based procedures; application of the 1.3 cap on retrofit strength for ASCE 41 and CEBC Appendix A - Chapter A4 retrofits; and calculation of spectral capacity with FEMA P-807.
The adequacy of an investigated load path may be confirmed by the judgment of the design professional, without calculations, but is subject to approval by the Department. Judgment should be based on the presence of a positive connection with multiple or redundant attachments distributed over the length of the wall line. For partitions perpendicular to floor framing above, blocking between floor joists nailed to the partition top plate (through a lath nailer, if present) should be deemed adequate for partitions with non-WSP sheathing.
Table B4.4. Investigation Requirements for Load Path between Partitions and Floor Framing Above
 
Condition
First / Target Story
Second / Upper Stories
Perimeter walls with non-WSP sheathing
May be assumed adequate
May be assumed adequate
Demising walls/partitions between units or between units and common areas
May be assumed adequate
May be assumed adequate
Any wall or partition with WSP sheathing where the top of the panel is nailed directly to a header beam, floor girder, or rim joist
May be assumed adequate
May be assumed adequate
Any wall or partition with WSP sheathing where the top of the panel is nailed only to a single or double top plate.
Confirm or provide load path
Confirm or provide load path
Room partitions within units, perpendicular to floor framing above
Investigate
May be assumed adequate
Room partitions within units, parallel to floor framing above
Investigate
Investigate
 
B4.5. Foundation elements. The investigation shall determine the nature of the existing foundation elements and supporting soils as needed for calculation of adjustment factors for overturning.
B5. Structure Characterization
B5.1. Story strength
B5.1.1. Wall assemblies. For each wall assembly present, a load-drift curve shall be computed by summing contributions from Table B5.1.1 at each drift level for each layer of sheathing. With approval of the Department, test results specific to the wall assembly or its components may be used in place of Table B5.1.1.
 
Commentary: See FEMA P-807 Section 4.4 and Appendix F regarding the development of Table B5.1.1 and the use of alternate test data.
The values in Table B5.1.1 are subject to the following additional requirements:
1.   Horizontal wood sheathing or wood siding shall be at least 1/2" thick and fastened to existing studs with at least two nails per board per stud. Otherwise, the expected strength shall be taken as 0.
2.   Where siding panel edges are lapped, each panel shall be nailed separately. Otherwise, the expected strength shall be taken as 0.
Table B5.1.1. Expected Strength for Load-Drift Curves [plf]
Sheathing Material
Drift, δj [%]
0.5
0.7
1.0
1.5
2.0
2.5
3.0
4.0
5.0
Sheathing Material
Drift, δj [%]
0.5
0.7
1.0
1.5
2.0
2.5
3.0
4.0
5.0
Stucco
333
320
262
0
--
--
--
--
--
Horizontal wood sheathing or wood siding
85
96
110
132
145
157
171
0
--
Diagonal wood sheathing
429
540
686
913
0
--
--
--
--
Plaster on wood lath
440
538
414
391
0
--
--
--
--
Plywood panel siding (T1-11), 6d@6
354
420
496
549
565
505
449
0
--
Gypsum wallboard
202
213
204
185
172
151
145
107
0
Plaster on gypsum lath
402
347
304
0
--
--
--
--
--
WSP, 8d@6
521
621
732
812
836
745
686
0
--
WSP, 8d@4
513
684
826
943
1,018
1,080
1,112
798
0
WSP, 8d@3
1,072
1,195
1,318
1,482
1,612
1,664
1,686
1,638
0
WSP, 8d@2
1,393
1,553
1,713
1,926
2,096
2,163
2,192
2,130
0
WSP, 10d@6
548
767
946
1,023
1,038
1,055
1,065
843
0
WSP, 10d@4
707
990
1,275
1,420
1,466
1,496
1,496
1,185
0
WSP, 10d@3
940
1,316
1,696
1,889
1,949
1,990
1,990
1,576
0
WSP, 10d@2
1,120
1,568
1,999
2,248
2,405
2,512
2,512
2,231
0
 
B5.1.1.1. Wall assemblies without wood structural panel sheathing. The assembly load drift curve is the sum of the load drift curves for each of the sheathing layers.
B5.1.1.2. Wall assemblies with wood structural panel sheathing. The assembly load drift curve is whichever of the following two load-drift curves has the larger peak strength:
1.   The assembly load-drift curve using 50 percent of the strength of the wood structural panel layers and 100 percent of the strength of the other sheathing materials.
2.   The assembly load-drift curve using 100 percent of the strength of the wood structural panel layers and 50 percent of the strength of the other sheathing materials.
B5.1.2. Wall line assignment. Each segment of sheathed wall framing within a story shall be assigned to a wall line. Wall lines shall satisfy the following rules:
1.   Full-height wall segments separated by window or door openings but connected by sheathed segments and continuous framing above or below the opening shall be assigned to the same wall line, unless other rules require them to be treated separately.
2.   Wall segments assigned to the same wall line shall not be offset out-of-plane from adjacent segments by more than four feet.
3.   At bay windows, the wall segments within the common plane shall be assigned to the same wall line if they satisfy the other rules, but the wall segments within the cantilevered portions of the bay shall not be counted toward the wall-line strength.
4.   Wall segments of different heights, including wall segments along a stepped foundation, shall be assigned to separate wall lines.
5.   A wall segment of varying height due to a sloped foundation shall be assigned to a separate wall line, and its height shall be taken as the average height of the segment.
6.   Wall segments of different wall assemblies shall be assigned to separate wall lines.
7.   Where hold-downs exist at each end of a wall segment, that segment may be considered a separate wall line.
8.   Wall segments less than one foot long shall be treated as openings.
9.   Wall segments between openings with height-to-length ratios greater than 8:1 shall be treated as openings.
10.   Steel elements (moment frames, cantilever columns, etc.) shall be assigned to separate wall lines.
11.   Wall segments or frames considered to have significant damage, deterioration, or construction defects may be counted toward a wall line’s strength but shall have their load-drift strength values reduced.
B5.1.3. Wall line load-drift curve. For each wall line, a load-drift curve shall be computed by multiplying the applicable wall assembly load-drift curve by the wall line’s length and by applicable adjustment factors per Bulletin Equation B5.1.3-1.
fw = (vw)(Lw)(Qopen)(Qot)   (Equation B5.1.3-1)
where:
fw is the load-drift curve of wall line w, expressed as a function of drift.
vw is the load-drift curve of the wall assembly associated with wall line w, as derived per Bulletin Section B5.1.1 and adjusted for height variation per Bulletin Section B5.1.3.1.
B5.1.3.1. Adjustment for height variation. Where first story wall lines in a given direction are of different heights, the load-drift curve of the wall assembly of each wood-frame wall line shall be adjusted to account for increased drift demands in all but the tallest first story wall line. This may be done by shifting the assembly load-drift curve from the standard set of drifts given in Table B5.1.1 to an adjusted set of drifts for each wall line, given by Equation B5.1.3.1-1.
   (Equation B5.1.3.1-1)
B5.1.3.2 Adjustment for openings. Each wall line load-drift curve shall account for the effects of openings within it. This may be done by applying the adjustment factor for openings, given by Equation B5.1.3.2-1 and Equation B5.1.3.2-2.
Qopen = 0.92a - 0.72a2 + 0.80a3    (Equation B5.1.3.2-1)
   (Equation B5.1.3.2-2)
where:
 
= sum of the areas of the openings within the wall line
= sum of the lengths of the full-height wall segments within the wall line.
B5.1.3.3. Adjustment for overturning. Each wall line load-drift curve shall account for the effects of overturning demand and resistance. This may be done by applying the adjustment factor for overturning, given by Equation B5.1.3.3-1 or, for existing upper-story wall lines only, by Table B5.1.3.3.
   (Equation B5.1.3.3-1)
where:
Mot is the overturning demand on the wall line and Mr is the resisting moment due to all available dead loads tributary to the wall line plus the effects of any tie-down hardware.
 
Commentary: See FEMA P-807 Section 4.5.3.2 for guidance on calculating Qot.
   Table B5.1.3.3. Default Adjustment Factor for Overturning, Qot , for Existing Upper Story Wall Lines
 
Number of stories above
Perpendicular to Framing
Parallel to Framing
Unknown or mixed
Two or more
0.95
0.85
0.85
One
0.85
0.80
0.80
None (Top story)
0.75
0.75
0.75
 
B5.1.4. Story load-drift curves. For each story, in each direction, a load-drift curve shall be computed by adding the load-drift curves of all the walls in that story and aligned in that direction.
 
Commentary: Where all the wall line load-drift curves are mapped to the same set of drifts, the summation is straightforward. Where some first story wall lines have load-drift curves mapped to a height-adjusted set of drifts, load values at the standard drift values should be determined by linear interpolation. Once interpolated values are calculated, the various load- drift curves can again be added in a straightforward way based on the standard drift values. See FEMA P-807 Section 4.6 for additional discussion.
B5.2. First story torsion
B5.2.1. Center of strength. The center of strength for the first and second stories shall be determined based on the wall line loads at the drift at which the story strength in the corresponding story and direction occurs.
 
Commentary: FEMA P-807 Section 4.6.4 illustrates the calculation of the center of strength.
B5.2.2. First story torsional demand. The first story torsional demand represents the effect of the first story strength acting at the torsional eccentricity, given by Equation B5.2.2-1.
τ1 = exV1y + eyV1x    (Equation B5.2.2-1)
B5.2.3. First story load-rotation curve. For the first story, a load-rotation curve shall be derived, relating torsion about the story center of strength to the resulting rotation of the story, assuming a rigid second floor diaphragm and accounting for the load-drift behavior of each first story wall line. The load-rotation curve shall consider rotation angles up to at least the rotation associated with 5 percent in-plane drift in at least one first story wall line.
 
Commentary: FEMA P-807 Section 4.6.6 illustrates one method for calculating of the load-rotation curve, dividing the rotation range of interest into ten even increments.
B5.3. Characteristic coefficients
B5.3.1. Base-normalized upper-story strength. The base-normalized upper-story strength shall be calculated for each principal direction per Equation B5.3.1-1.
    (Equation B5.3.1-1)
B5.3.2. Weak-story ratio. The weak-story ratio shall be calculated for each principal direction per Equation B5.3.2-1.
   (Equation B5.3.2-1)
B5.3.3. Strength degradation ratio. The strength degradation ratio, CD, shall be calculated for each principal direction based on the first story load-drift curves.
 
Commentary: FEMA P-807 Section 4.7.4 illustrates the calculation of the strength degradation ratio.
B5.3.4. Torsion coefficient. The torsion coefficient, given by Equation B5.3.4-1, need not be taken greater than 1.4.
    (Equation B5.3.4-1)
B5.3.5. Story height factor. The story height factor shall be calculated for each principal direction per Equation B5.3.5-1, where H1 is given in inches.
Qs = 0.55 + 0.0047 H1    (Equation B5.3.5-1)
B6. Evaluation
B6.1. Evaluation relative to the performance objective. Subject to the additional requirements of Bulletin Section B1.2, any eligible structure shall be deemed to comply with the requirements of this Bulletin if its spectral capacity in each principal direction exceeds the spectral demand.
B6.1.1. Spectral capacity. Spectral capacity in each direction shall be calculated from Equations B6.1.1-1 through B6.1.1-5, using drift limit POE adjustment factors given in Table B6.1.1 for the drift limit POE specified in Bulletin Section B1.1.3. Drift limit POE adjustment factors for intermediate values of drift limit POE shall be calculated by linear interpolation.
 
Commentary: SFEBC Chapter 5E does not require the calculation of a POE. However, given a spectral demand, the POE of a structure can be calculated. See FEMA P-807 Section 5.4.2 or Appendix B model provision 6.2.
    (Equation B6.1.1-1)
    (Equation B6.1.1-2)
   (Equation B6.1.1-3)
    (Equation B6.1.1-4)
   (Equation B6.1.1-5)
   Table B6.1.1. Drift limit probability of exceedance adjustment factors.
POE
αPOE,1
αPOE,0
2%
0.36
0.29
5%
0.44
0.37
10%
0.53
0.46
20%
0.66
0.60
30%
0.77
0.73
50%
1.00
1.00
60%
1.14
1.16
70%
1.30
1.37
80%
1.52
1.66
 
B7. Retrofit
B7.1. Retrofitted first story strength. The first story strength of the retrofitted structure shall account for all existing unaltered elements, existing altered elements, new elements provided to increase story strength, and new elements provided to correct aspects of eligibility or building survey non-compliance.
Exception: Out-of-plane or weak axis strength of existing or retrofit elements need not be considered where the sum of those strengths is deemed insignificant to the total story strength.
 
Commentary: The Exception is intended to allow wood frame walls and pin-based frames to be ignored in their weak directions, and to allow the Department to accept the engineer’s judgment or to require modeling of fixed-based frames and cantilever columns in their weak directions.
B7.2. Retrofit compliance. The retrofit design shall demonstrate that both of the following conditions are true:
1.   The retrofitted structure’s spectral capacity in each principal direction exceeds the spectral demand.
2.   The first story strength of the retrofitted structure in each principal direction satisfies Equation B7.2-1.
    (Equation B7.2-1)
 
Commentary: The intent of Equation B7.2-1 is to ensure that over-strengthening the first story is not miscounted as beneficial. Given the maximum POE, if the required first story strength cannot be achieved without exceeding this limit, it indicates that the proposed retrofit would push failure to the second story and would not achieve its intended effect. Where the exception to Bulletin Section B1.1.3 is applied, the higher POE value will give the same spectral capacity for less first story strength, effectively allowing a lighter retrofit that might satisfy the equation.
FEMA P-807 Section 6.2.1 provides formulas for estimating the strength of the retrofitted first story needed to reach the required spectral capacity, but use of the estimating formulas is not required.
B7.3 Additional requirements where the Exception to Bulletin Section B1.1.3 is applied. The retrofit design shall demonstrate that all of the following additional conditions is true:
1.   The first story strength of the retrofitted structure in each principal direction satisfies Equation B7.3-1.
2.   The retrofit design satisfies the requirements of Bulletin Section B7.3.1.
    (Equation B7.3-1)
B7.3.1 Minimized torsional eccentricity. Retrofit elements shall be located along perimeter wall lines so as to minimize the torsional eccentricity of the retrofitted structure, or so as to satisfy Equations B7.3.1-1 and B7.3.1-2. This requirement may be waived with the approval of the Department to accommodate other building or planning code requirements or to avoid disproportionate construction costs.
   (Equation B7.3.1-1)
   (Equation B7.3.1-2)
B7.4 Design criteria for retrofit elements. Retrofit elements shall conform to the general requirements in this section and to the applicable requirements in the following subsections.
 
Commentary: See Bulletin Section B3.4 for discussion of retrofit systems for which FEMA P-807 is suitable.
1.   Where retrofit elements are sized based on unit strengths from codes or standards, the expected strength, without strength reductions or resistance factors, may be used.
 
Commentary: The allowance of expected strength, which is typically greater than nominal strength (see Bulletin Section A3.2.2) is appropriate because FEMA P-807 requires retrofit elements to be ductile (or, in ASCE 31 or ASCE 41 terms, deformation-controlled).
2.   The load-drift curve of each retrofit element type shall be based on expected material properties, including overstrength. The full expected capacity, without strength reduction or resistance factors, shall be used to calculate load-drift curves and peak strengths.
3.   Each retrofit element shall be such that a load-drift curve based on similar elements alone would have a strength degradation ratio, CD, greater than or equal to 0.8.
4.   The load-drift curve of each retrofit element type shall be defined up to five percent interstory drift or as needed to fully characterize the retrofit design per Bulletin Section B5.
5.   Materials and systems for all retrofit elements shall be generally consistent with provisions of the building code for new construction of the same occupancy and risk category. SFEBC Section 302.4 and other provisions that allow like materials for alterations do not apply to retrofits mandated by SFEBC Chapter 5E. However, the Department may waive restrictions on certain systems based on building height, irregularity, seismic design category, or other conditions not related to the critical deficiencies of the story being evaluated or retrofitted.
 
Commentary: FEMA P-807 presumes that retrofit elements will be reliably ductile (as indicated by the requirement for a minimum CD value in item 3 above). Systems detailed as special should generally be deemed to comply with this requirement, but systems detailed as intermediate or ordinary may also be shown to be adequate. The final sentence of this provision allows intermediate and ordinary steel frames to be used in seismic design category D and E; see also ASCE 7-16 Sections 12.2.5.6 and 12.2.5.7.
6.   Design criteria for load path components and connections shall be appropriate to the performance objective and shall be based on the building code for new construction, appropriate provisions of other criteria allowed by SFEBC Section 506E.2, or principles of capacity design.
B7.4.1. Wood structural panel shear walls. Load-drift curves for wood structural panel retrofit elements shall be calculated in accordance with Bulletin Section B5. Existing shear walls modified by replacing sheathing materials or by adding supplemental wood structural panels shall be considered retrofit elements.
B7.4.2. Steel special moment-resisting frames. Steel retrofit elements that conform to the requirements of AISC 341-05 or AISC 341-10 for Special Moment Frames shall be deemed to comply with the provision requiring a CD value greater than or equal to 0.8. The load-drift curve may be characterized per FEMA P-807 Figure 6-7 as follows: Vy = ZFye with post-yield strengthening up to 1.2Vy at dmax, with dmax = dy + 4%.
B7.4.3. Steel intermediate moment-resisting frames. For steel retrofit elements that conform to the requirements of AISC 341 for Intermediate Moment Frames, the load-drift curve may be characterized per FEMA P-807 Figure 6-7 as follows: Vy = ZFye with no post-yield strengthening, and dmax = dy + 2%.
B7.4.4. Steel ordinary moment-resisting frames. For steel retrofit elements that conform to the requirements of AISC 341 for Ordinary Moment Frames, the load-drift curve may be characterized per FEMA P-807 Figure 6-7 as follows: Vy per AISC 360 Chapter F, using Fye instead of Fy, dmax = 2%.
B7.4.5. Steel special cantilever columns. For steel retrofit elements that conform to the requirements of AISC 341 for Special Cantilevered Column systems, the load-drift curve may be characterized per FEMA P-807 Figure 6-7 as follows: Vy = ZFye with no post-yield strengthening, and dmax = dy + 2%.
B7.4.6. Steel ordinary cantilever columns. FEMA P-807 shall not be used to demonstrate compliance of steel ordinary cantilever columns as retrofit elements.
B7.4.7. Steel buckling-restrained braced frames. Steel retrofit elements that conform to the requirements of AISC 341 for buckling-restrained braced frames shall be deemed to comply with the provision requiring a CD value greater than or equal to 0.8.
 
Commentary: FEMA P-807 Section 6.5.5 offers further guidance on characterizing and designing these elements.
B7.4.8. Damping systems. FEMA P-807 may be used to demonstrate compliance of hysteretic damping systems that rely on the yielding of steel components by modeling the retrofit elements as bi-linear systems similar to other structural steel systems. The Department is authorized to require third party peer review at the expense of the permit applicant.
FEMA P-807 shall not be used to demonstrate compliance of other damping systems, including viscous- or friction-damped systems.
 
Commentary: Viscous- and friction-damped systems cannot be designed with FEMA P-807 because the FEMA P-807 surrogate models did not include these mechanisms.
B7.5 Design criteria for load path elements and components. The retrofit design shall confirm or provide a load path from the second floor diaphragm through the first story seismic force-resisting elements and their foundations, to the supporting soils. The ultimate strength of load path components shall be reduced with strength reduction factors as needed to ensure that the load-path elements are able to develop the strength and the intended mechanism of first story wall and frame elements. Specific design criteria may be derived from principles of capacity design, from other criteria allowed by SFEBC Section 506E.2, or from building code provisions for new construction involving the overstrength factor, Ω0.
B7.5.1. Foundations and overturning. New foundation elements shall be provided as needed to resist bearing, sliding, and overturning forces associated with the retrofit elements acting at their strength. Connections and load path components related to wall or frame overturning shall not assume any acting dead load except for the self-weight of the retrofit element unless the retrofit element incorporates existing gravity load-carrying framing or unless the design and construction explicitly transfer existing dead load to the retrofit element. The weight of foundation elements may be considered if adequately connected.
B7.5.2. Second floor diaphragm. The second floor diaphragm shall be strengthened as needed to ensure that expected forces can be transferred between the diaphragm and the first-story elements.
B7.5.3. Fixed-base frame columns. Moment-resisting frame systems and cantilever column systems whose capacity assumes other than a pin-based condition shall be provided with connection details demonstrated to develop the assumed fixity and the assumed column strength. In general, an anchor-bolted base plate without substantial embedment within a foundation element is not considered to provide a fixed-base condition.
B8. Design quality assurance
B8.1. Structural calculations. Structural calculations and documentation of evaluations and retrofit designs using FEMA P-807 shall include, at minimum:
1.   Plans and/or elevations for each floor level identifying each wall line and showing the wall assembly, length, location, and openings.
2.   A schedule of wall assemblies and load drift curves for existing, altered, and new elements.
3.   A list or schedule of wall lines with overturning and opening adjustments.
4.   Derivation of characteristic coefficients.
5.   Spectral capacity calculations.
6.   Site-specific spectral demand calculations.
B8.2. Use of the FEMA P-807 Weak Story Tool
Reserved
Part C. APPLICATION OF ASCE 41-13 TO EVALUATION AND RETROFIT DESIGN
 
DISCUSSION   :
Further development of this section is expected as needed to address issues specific to Chapter 5E. The sections outlined below cover broad issues consistent with Chapter 5E. Otherwise, use of this standard is subject to existing Department procedures for implementation of SFBC 104A.2.8, Alternate materials, design, and methods of construction.
C1. Required scope of work
1.   No nonstructural evaluation or retrofit is required.
2.   Retrofit strength need not exceed 1.3 times the strength of the story above. Wherever the strength of two stories is being compared, an adequate load path must be assumed for all walls and partitions in the upper story.
 
Commentary: This requirement prevents underestimating the upper story strength. It will apply for calculations of weak story or soft story ratio in ASCE 31/41, CEBC Appendix A - Chapter A4, and other code-based procedures; application of the 1.3 cap on retrofit strength for ASCE 41 and CEBC Appendix A - Chapter A4 retrofits; and calculation of spectral capacity with FEMA P-807.
Part D. APPLICATION OF ASCE 41-06 TO EVALUATION AND RETROFIT DESIGN
 
DISCUSSION   :
Further development of this section is expected as needed to address issues specific to Chapter 5E. The sections outlined below cover broad issues consistent with Chapter 5E. Otherwise, use of this standard is subject to existing Department procedures for implementation of SFBC 104A.2.8, Alternate materials, design, and methods of construction.
D1. Required scope of work
1.   No nonstructural evaluation or retrofit is required.
2.   Retrofit strength need not exceed 1.3 times the strength of the story above. Wherever the strength of two stories is being compared, an adequate load path must be assumed for all walls and partitions in the upper story.
 
Commentary: This requirement prevents underestimating the upper story strength. It will apply for calculations of weak story or soft story ratio in ASCE 31/41, CEBC Appendix A - Chapter A4, and other code-based procedures; application of the 1.3 cap on retrofit strength for ASCE 41 and CEBC Appendix A - Chapter A4 retrofits; and calculation of spectral capacity with FEMA P-807.
Part E. APPLICATION OF ASCE 31-03 TO EVALUATION
 
DISCUSSION   :
Further development of this section is expected as needed to address issues specific to Chapter 5E. The sections outlined below cover broad issues consistent with Chapter 5E. Otherwise, use of this standard is subject to existing Department procedures for implementation of SFBC 104A.2.8, Alternate materials, design, and methods of construction.
E1. Required scope of work
1.   No nonstructural evaluation is required.
2.   Wherever the strength of two stories is being compared, an adequate load path must be assumed for all walls and partitions in the upper story.
 
Commentary: This requirement prevents underestimating the upper story strength. It will apply for calculations of weak story or soft story ratio in ASCE 31/41, CEBC Appendix A - Chapter A4, and other code-based procedures; application of the 1.3 cap on retrofit strength for ASCE 41 and CEBC Chapter Appendix A - Chapter A4 retrofits; and calculation of spectral capacity with FEMA P-807.
Part F. APPLICATION OF THE CURRENT EDITION OF CEBC APPENDIX A - CHAPTER A4 TO RETROFIT DESIGN
F1. Modifications and interpretations of CEBC Appendix A - Chapter A4. Compliance with SFEBC Chapter 5E using CEBC Appendix A - Chapter A4 shall require compliance with that code chapter and its reference codes and standards except as otherwise modified, waived, or interpreted in this section and Bulletin Part A.
The following modifications and interpretations refer to Appendix A - Chapter A4 section numbers.
A401.1 Purpose
 
Commentary: This provision refers to “minimum standards.” In the context of Appendix A - Chapter A4, this means minimum standards for policy equivalence with other criteria when retrofit is triggered elsewhere in the CEBC. In the context of SFEBC Chapter 5E, the provisions of Appendix A - Chapter A4 might or might not require the same scope of retrofit as other criteria allowed by SFEBC Section 506E.2. The other criteria are acceptable even if they require less retrofit scope or produce retrofit designs with lower capacity than Appendix A - Chapter A4.
A401.2 Scope. Omit.
 
Commentary: When used for compliance with SFEBC Chapter5E, the scope and applicability of Appendix A - Chapter A4 is established by Ordinance 66-13. The absence of any condition listed by Section A401.2 has no bearing on compliance with Chapter 5E.
A402 Definitions. Add, omit, or revise the following definitions as follows:
BUILDING CODE. The current San Francisco Building Code.
GROUND FLOOR. A target story, generally a basement story that extends above grade or the first story above grade plane. Alternately, depending on context, GROUND FLOOR might mean the floor level at the base of a target story.
A403.1. Omit the exception and revise the first sentence as follows:
A403.1 General. All modifications required ... the building code provisions for new construction, except as modified by this chapter and applicable Administrative Bulletins.
 
Commentary: The exception is not necessary because Section A404 is omitted. See below.
A403.2. Omit the exception and revise the provision as follows:
A403.2 Scope of analysis. This chapter requires the alteration, repair, replacement or addition of structural elements and their connections to meet the strength and stiffness requirements herein. The lateral-load-path analysis shall include the resisting elements and connections from the wood diaphragm immediately above any target story to the foundation soil interface. Stories above the uppermost target story shall be considered in the analysis but need not be modified. The lateral-load-path analysis for added structural elements shall also include evaluation of the allowable soil-bearing and lateral pressures in accordance with the building code. Where any portion of a building within the scope of this chapter is constructed on or into a slope, the lateral force-resisting system at and below the first story above grade plane shall be analyzed for the effects of concentrated lateral forces caused by this hillside condition.
A403.3. Correct Δ0 to Ω0 in multiple places. Also, add the following sentences at the end of the section:
A403.3 Design base shear and design parameters. ... Despite any other requirement of Section A403.3 or A403.4, the total expected strength of retrofit elements added to any target story need not exceed 1.3 times the expected strength of the story immediately above, as long as the retrofit elements are located symmetrically about the center of mass of the story above or so as to minimize torsion in the target story.
 
Commentary: The added sentence implements the SEAONC recommendation to cap the required strength, consistent with FEMA P-807.
Exception 4: For retrofit systems involving different seismic force-resisting systems in the same direction within the same story, resisting elements are permitted to be designed using the least value of R for the different structural systems found in each independent line of resistance if the following conditions are met: (1) Risk Category I or II building, (2) four stories or less above grade plane, and (3) the seismic force-resisting systems are composed of WSP shear walls, steel moment-resisting frames, steel cantilever columns, and steel braced frames. Values for Cd and Ω0 shall be consistent with the R value used.
Add the following subsection:
A403.3.1 Story strength. Calculation of story strength and identification of irregularities in Section A403.3 shall be based on the expected strength of all wall lines, even if sheathed with nonconforming materials. The strength of a wall line may be reduced to account for inadequate load path or overturning resistance.
 
Commentary: The expected strength of the story above may be calculated using the FEMA P-807 criteria given in Bulletin Section B5.1. The requirement to assume an adequate load path prevents underestimating the upper story strength. It will apply for calculations of weak story or soft story ratio in ASCE 31/41, CEBC Appendix A - Chapter A4, and other code-based procedures; application of the 1.3 cap on retrofit strength for ASCE 41 and IEBC Appendix A - Chapter A4 retrofits; and calculation of spectral capacity with FEMA P-807.
A403.5. Revise the subsection heading and the provision as follows:
A403.5. Deformation Compatibility and PΔ effects. The requirements of the building code shall apply, except as modified herein. All structural framing elements and their connections not required by design to be part of the lateral force-resisting system shall be designed and/or detailed to be adequate to maintain support of expected gravity loads when subjected to the expected deformations caused by seismic forces. Increased demand due to PΔ effects and story side sway stability shall be considered in retrofit stories that rely on the strength and stiffness of cantilever columns for lateral resistance.
 
Commentary: This revision is consistent with a change approved for the latest edition of IEBC.
A403.8. Revise the provision as follows:
A403.8 Horizontal diaphragms. The diaphragm immediately above the target story shall be evaluated and/or strengthened as required by Bulletin Section A1.1. Rotational effects shall be accounted for when asymmetric wall stiffness increases shear demands.
 
Commentary: This revision is consistent with a change approved for the latest edition of IEBC.
A403.9.1 Revise the provision as follows:
A403.9.1 Gypsum or cement plaster products. Gypsum or cement plaster products shall not be used to provide lateral resistance in a target story.
A404. Omit Section A404 entirely.
 
Commentary: Section A404 applies to two-story buildings only. Two-story buildings are exempt from SFEBC Chapter 5E.
A405.1. Revise the provision as follows:
A405.1 New materials. New materials shall meet the requirements of the building code, except where allowed by this chapter or applicable Administrative Bulletins.
A407 Quality Control. Omit Section A407 entirely.
 
Commentary: Bulletin Sections A4 and A5, as well as AB 106, apply instead.
Part G. GUIDELINES FOR ALTERNATIVE RATIONAL DESIGN BASES
 
DISCUSSION   :
Further development of this section is expected as needed to address issues specific to Chapter 5E. Sections to be outlined below will cover broad issues consistent with Chapter 5E. Otherwise, use of this standard is subject to existing Department procedures for implementation of SFBC 104A.2.8, Alternate materials, design, and methods of construction.
 
Revision signed by:
Tom C. Hui, S.E., C.B.O.          June 27, 2017
Director
Department of Building Inspection
Originally approved by Building Inspection Commission on November 20, 2013
Revisions approved November 19, 2014; December 16, 2015; May 19, 2016; May 17, 2017