What rules apply if a building is moved into a flood hazard area?

Grounded in the retrieved California Existing Building Code — click a citation to read the verbatim passage:

• CEBC § 5.1 High relevance — show source text

  G104.4 Activities in riverine flood hazard areas. In riverine flood hazard areas where design flood elevations are specified but floodways have not been designated, the floodplain administrator shall not permit any new construction, substantial improvement or other development, including fill, unless the applicant submits an engineering analysis prepared by a registered design professional, demonstrating that the cumulative effect of the proposed development, when combined with all other existing and anticipated flood hazard area encroachment, will not increase the design flood elevation more than 1 foot (305 mm) at any point within the community.

  G104.5 Floodway encroachment. Prior to issuing a permit for any floodway encroachment, including fill, new construction, substantial improvements and other development or land-disturbing activity, the floodplain administrator shall require submission of a certification, prepared by a registered design professional, along with supporting technical data, demonstrating that such development will not cause any increase of the base flood level.

  G104.5.1 Floodway revisions. A floodway encroachment that increases the level of the base flood is authorized if the applicant has applied for a conditional Flood Insurance Rate Map (FIRM) revision and has received the approval of the Federal Emergency Management Agency (FEMA).

  G104.6 Watercourse alteration. Prior to issuing a permit for any alteration or relocation of any watercourse, the floodplain administrator shall require the applicant to provide notification of the proposal to the appropriate authorities of all adjacent government jurisdictions, as well as appropriate state agencies. A copy of the notification shall be maintained in the permit records and submitted to FEMA.

  2025 CALIFORNIA BUILDING CODE APPENDIX G-3

  on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

  APPENDIX G—FLOOD-RESISTANT CONSTRUCTION

  G104.6.1 Engineering analysis. The floodplain administrator shall require submission of an engineering analysis, prepared by a registered design professional, demonstrating that the flood-carrying capacity of the altered or relocated portion of the watercourse will not be decreased. Such watercourses shall be maintained in a manner that preserves the channel’s flood-carrying capacity.

  G104.7 Alterations in coastal areas. Prior to issuing a permit for any alteration of sand dunes and mangrove stands in coastal highhazard areas and coastal A zones, the floodplain administrator shall require submission of an engineering analysis, prepared by a registered design professional, demonstrating that the proposed alteration will not increase the potential for flood damage.

  G104.8 Records. The floodplain administrator shall maintain a permanent record of all permits issued in flood hazard areas, including supporting certifications and documentation required by this appendix and copies of inspection reports, design certifications and documentation of elevations required in Section 1612 of this code and Section R306 of the California Residential Code .

  G104.9 Inspections. Development for which a permit under this appendix is required shall be subject to inspection. The floodplain administrator or the floodplain administrator’s designee shall make, or cause to be made, inspections of all development in flood hazard areas authorized by issuance of a permit under this appendix.

  G104.10 Use of changed technical data. The floodplain administrator and the applicant shall not use changed flood hazard area boundaries or base flood elevations for proposed buildings or developments unless the floodplain administrator or applicant has applied for a conditional Flood Insurance Rate Map (FIRM) revision and has received the approval of the Federal Emergency Management Agency (FEMA).

  SECTION G105—PERMITS

• CEBC § 1402.2 High relevance — show source text

  [BS] 1402.2 Foundation. The foundation system of relocated buildings shall comply with the California Building Code or the Califor- nia Residential Code, as applicable.

  [BS] 1402.2.1 Connection to the foundation. The connection of the relocated building to the foundation shall comply with the California Building Code or the California Residential Code, as applicable.

  [BS] 1402.3 Wind loads. Buildings shall comply with California Building Code or California Residential Code wind provisions, as applicable.

  Exceptions:

  1. Detached one- and two-family dwellings and Group U occupancies where wind loads at the new location are not higher than those at the previous location.
  2. Structural elements whose stress is not increased by more than 10 percent.

  [BS] 1402.4 Seismic loads. Buildings shall comply with California Building Code or California Residential Code seismic provisions at the new location, as applicable.

  Exceptions:

  1. Structures in Seismic Design Categories A and B and detached one- and two-family dwellings in Seismic Design Categories A, B and C where the seismic loads at the new location are not higher than those at the previous location.
  2. Structural elements whose stress is not increased by more than 10 percent.

  [BS] 1402.5 Snow loads. Structures shall comply with California Building Code or California Residential Code snow loads, as applicable, where snow loads at the new location are higher than those at the previous location.

  Exception: Structural elements whose stress is not increased by more than 5 percent.

  [BS] 1402.6 Flood hazard areas. If relocated or moved into a flood hazard area, structures shall comply with Section 1612 of the California Building Code, or Section R306 of the California Residential Code, as applicable.

  2025 CALIFORNIA EXISTING BUILDING CODE 14-3

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  RELOCATED OR MOVED BUILDINGS

  [BS] 1402.7 Required inspection and repairs. The code official shall be authorized to inspect, or to require approved professionals to inspect at the expense of the owner, the various structural parts of a relocated building to verify that structural components and connections have not sustained structural damage. Any repairs required by the code official as a result of such inspection shall be made prior to the final approval.

  14-4 2025 CALIFORNIA EXISTING BUILDING CODE

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  CALIFORNIA EXISTING BUILDING CODE – MATRIX ADOPTION TABLE

  CHAPTER 15 – CONSTRUCTION SAFEGUARDS

  (Matrix Adoption Tables are nonregulatory, intended only as an aid to the code user. See Chapter 1 for state agency authority and building applications.)

  Adopting Agency	BSC	BSC- CG	SFM	HCD	Col6	Col7	DSA	Col9	Col10	OSHPD	Col12	Col13	Col14	Col15	Col16	Col17	BSCC	DPH	AGR	DWR	CEC	CA	SL	SLC
  Adopting

• CEBC § 105.2 High relevance — show source text

  SECTION G103—APPLICABILITY

  G103.1 General. This appendix, in conjunction with this code, provides minimum requirements for development located in flood hazard areas, including:

  1. The subdivision of land.

  2. Site improvements and installation of utilities.

  3. Placement and replacement of manufactured homes.

  4. Placement of recreational vehicles.

  5. New construction and repair, reconstruction, rehabilitation or additions to new construction.

  6. Substantial improvement of existing buildings and structures, including restoration after damage.

  7. Installation of tanks.

  8. Temporary structures.

  9. Temporary or permanent storage, utility and miscellaneous Group U buildings and structures.

  10. Certain building work exempt from permit under Section 105.2 and other buildings and development activities.

  G103.2 Establishment of flood hazard areas. Flood hazard areas are established in Section 1612.3 of this code, adopted by the applicable governing authority on [ INSERT DATE ] .

  SECTION G104—POWERS AND DUTIES

  G104.1 Permit applications. All applications for permits shall comply with the following:

  1. The floodplain administrator shall review all permit applications to determine whether proposed development is located in flood hazard areas established in Section G103.2.

  2. Where a proposed development site is in a flood hazard area, all development to which this appendix is applicable as specified in Section G103.1 shall be designed and constructed with methods, practices and materials that minimize flood damage and that are in accordance with this code and ASCE 24.

  G104.2 Other permits. It shall be the responsibility of the floodplain administrator to ensure that approval of a proposed development shall not be given until proof that necessary permits have been granted by federal or state agencies having jurisdiction over such development.

  G104.3 Determination of design flood elevations. If design flood elevations are not specified, the floodplain administrator is authorized to require the applicant to meet one of the following:

  1. Obtain, review and reasonably utilize data available from a federal, state or other source.
  2. Determine the design flood elevation in accordance with accepted hydrologic and hydraulic engineering techniques. Such analyses shall be performed and sealed by a registered design professional. Studies, analyses and computations shall be submitted in sufficient detail to allow review and approval by the floodplain administrator. The accuracy of data submitted for such determination shall be the responsibility of the applicant.

  G104.4 Activities in riverine flood hazard areas. In riverine flood hazard areas where design flood elevations are specified but floodways have not been designated, the floodplain administrator shall not permit any new construction, substantial improvement or other development, including fill, unless the applicant submits an engineering analysis prepared by a registered design professional, demonstrating that the cumulative effect of the proposed development, when combined with all other existing and anticipated flood hazard area encroachment, will not increase the design flood elevation more than 1 foot (305 mm) at any point within the community.

  G104.5 Floodway encroachment. Prior to issuing a permit for any floodway encroachment, including fill, new construction, substantial improvements and other development or land-disturbing activity, the floodplain administrator shall require submission of a certification, prepared by a registered design professional, along with supporting technical data, demonstrating that such development will not cause any increase of the base flood level.

  G104.5.1 Floodway revisions. A floodway encroachment that increases the level of the base flood is authorized if the applicant has applied for a conditional Flood Insurance Rate Map (FIRM) revision and has received the approval of the Federal E

• CEBC § 6.1 High relevance — show source text

  APPENDIX G—FLOOD-RESISTANT CONSTRUCTION

  G104.6.1 Engineering analysis. The floodplain administrator shall require submission of an engineering analysis, prepared by a registered design professional, demonstrating that the flood-carrying capacity of the altered or relocated portion of the watercourse will not be decreased. Such watercourses shall be maintained in a manner that preserves the channel’s flood-carrying capacity.

  G104.7 Alterations in coastal areas. Prior to issuing a permit for any alteration of sand dunes and mangrove stands in coastal highhazard areas and coastal A zones, the floodplain administrator shall require submission of an engineering analysis, prepared by a registered design professional, demonstrating that the proposed alteration will not increase the potential for flood damage.

  G104.8 Records. The floodplain administrator shall maintain a permanent record of all permits issued in flood hazard areas, including supporting certifications and documentation required by this appendix and copies of inspection reports, design certifications and documentation of elevations required in Section 1612 of this code and Section R306 of the California Residential Code .

  G104.9 Inspections. Development for which a permit under this appendix is required shall be subject to inspection. The floodplain administrator or the floodplain administrator’s designee shall make, or cause to be made, inspections of all development in flood hazard areas authorized by issuance of a permit under this appendix.

  G104.10 Use of changed technical data. The floodplain administrator and the applicant shall not use changed flood hazard area boundaries or base flood elevations for proposed buildings or developments unless the floodplain administrator or applicant has applied for a conditional Flood Insurance Rate Map (FIRM) revision and has received the approval of the Federal Emergency Management Agency (FEMA).

  SECTION G105—PERMITS

  G105.1 Required. Any person, owner or owner’s authorized agent who intends to conduct any development in a flood hazard area shall first make application to the floodplain administrator and shall obtain the required permit.

  G105.2 Application for permit. The applicant shall file an application in writing on a form furnished by the floodplain administrator. Such application shall:

  1. Identify and describe the development to be covered by the permit.

  2. Describe the land on which the proposed development is to be conducted by legal description, street address or similar description that will readily identify and definitely locate the site.

  3. Include a site plan showing the delineation of flood hazard areas, floodway boundaries, flood zones, design flood elevations, ground elevations, proposed fill and excavation and drainage patterns and facilities.

  4. Include in subdivision proposals and other proposed developments with more than 50 lots or larger than 5 acres (20 234 m [2] ), base flood elevation data in accordance with Section 1612.3.1 if such data are not identified for the flood hazard areas estab lished in Section G103.2.

  5. Indicate the use and occupancy for which the proposed development is intended.

  6. Be accompanied by construction documents, grading and filling plans and other information deemed appropriate by the floodplain administrator.

  7. State the valuation of the proposed work.

  8. Be signed by the applicant or the applicant’s authorized agent.

• CEBC § 3-35 High relevance — show source text

  Exceptions:

  1. Buildings where the structural members of walls, floors, ceilings and roofs are entirely of noncombustible materials or pressure-preservative-treated wood.

  2. Where in addition to the requirements of Section R305.1, an approved method of protecting the foam plastic and structure from subterranean termite damage is used.

  3. On the interior side of basement walls.

  2025 CALIFORNIA RESIDENTIAL CODE 3-35

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  BUILDING PLANNING

  FIGURE R305.4—TERMITE INFESTATION PROBABILITY MAP

  Note: Lines defining areas are approximate only. Local conditions may be more or less severe than indicated by the region classification.

  SECTION R306—FLOOD-RESISTANT CONSTRUCTION

  R306.1 General. Buildings and structures constructed in whole or in part in flood hazard areas established in Table R301.2, and substantial improvement and repair of substantial damage of buildings and structures located in whole or in part in flood hazard areas, shall be designed and constructed in accordance with the provisions contained in this section. Buildings and structures that are located in more than one flood hazard area, including A Zones, Coastal A Zones and V Zones, shall comply with the provisions associated with the most restrictive flood hazard area. Buildings and structures located in whole or in part in identified floodways shall be designed and constructed in accordance with ASCE 24.

  R306.1.1 Alternative provisions. As an alternative to the requirements in Section R306, ASCE 24 is permitted subject to the limitations of this code and the limitations therein.

  R306.1.2 Structural systems. Structural systems of buildings and structures shall be designed, connected and anchored to resist flotation, collapse or permanent lateral movement due to structural loads and stresses from flooding equal to the design flood elevation.

  R306.1.3 Flood-resistant construction. Buildings and structures erected in areas prone to flooding shall be constructed by methods and practices that minimize flood damage.

  R306.1.4 Establishing the design flood elevation. The design flood elevation shall be used to define flood hazard areas. At a minimum, the design flood elevation shall be the higher of the following:

  1. The base flood elevation at the depth of peak elevation of flooding, including wave height, that has a 1-percent (100-year flood) or greater chance of being equaled or exceeded in any given year.
  2. The elevation of the design flood associated with the area designated on a flood hazard map adopted by the community, or otherwise legally designated.

  R306.1.4.1 Determination of design flood elevations. If design flood elevations are not specified, the building official is authorized to require the applicant to comply with either of the following:

  1. Obtain and reasonably use data available from a federal, state or other source.
  2. Determine the design flood elevation in accordance with accepted hydrologic and hydraulic engineering practices used to define special flood hazard areas. Determinations shall be undertaken by a registered design professional who shall document that the technical methods used reflect currently accepted engineering practice. Studies, analyses and computations shall be submitted in sufficient detail to allow thorough review and approval.
• CEBC § 1611A.1 High relevance — show source text

  TABLE 1611A.1—DESIGN STORM RETURN PERIOD BY RISK CATEGORY	Col2
  RISK CATEGORY	DESIGN STORM RETURN PERIOD
  I & II	100 years
  III	200 years
  IV	500 years

  1611 A .2 Ponding instability. Ponding instability on roofs shall be evaluated in accordance with ASCE 7.

  1611 A .3 Controlled drainage. Roofs equipped with hardware to control the rate of drainage shall be equipped with a secondary drainage system at a higher elevation that limits accumulation of water on the roof above that elevation. Such roofs shall be designed to sustain the load of rainwater that will accumulate on them to the elevation of the secondary drainage system plus the uniform load caused by water that rises above the inlet of the secondary drainage system at its design flow determined from Section 1611 A .1. Such roofs shall be checked for ponding instability in accordance with Section 1611 A .2.

  SECTION 1612 A —FLOOD LOADS

  1612 A .1 General. Within flood hazard areas as established in Section 1612 A .3, all new construction of buildings, structures and portions of buildings and structures, including substantial improvement and restoration of substantial damage to buildings and structures, shall be designed and constructed to resist the effects of flood hazards and flood loads. For buildings that are located in more than one flood hazard area, the provisions associated with the most restrictive flood hazard area shall apply.

  1612 A .2 Design and construction. The design and construction of buildings and structures located in flood hazard areas, including coastal high hazard areas and coastal A zones, shall be in accordance with Chapter 5 of ASCE 7 and ASCE 24. Elevators, escalators, conveying systems and their components shall conform to ASCE 24 and ASME A17.1/CSA B44 as applicable.

  Exception: Temporary structures complying with Section 3103.6.1.3.

  1612 A .3 Establishment of flood hazard areas. To establish flood hazard areas, the applicable governing authority shall adopt a flood hazard map and supporting data. The flood hazard map shall include, at a minimum, areas of special flood hazard as identified by the Federal Emergency Management Agency’s Flood Insurance Study (FIS) adopted by the local authority having jurisdiction where the project is located, as amended or revised with the accompanying Flood Insurance Rate Map ( FIRM ) and Flood Boundary and Flood- way Map (FBFM) and related supporting data along with any revisions thereto. The adopted flood hazard map and supporting data are hereby adopted by reference and declared to be part of this section.

  1612 A .3.1 Design flood elevations. Where design flood elevations are not included in the flood hazard areas established in Section 1612 A .3, or where floodways are not designated, the building official is authorized to require the applicant to do one of the following:

  1. Obtain and reasonably utilize any design flood elevation and floodway data available from a federal, state or other

  source.

  2. Determine the design flood elevation or floodway in accordance with accepted hydrologic and hydraulic engineering practices used to define special flood hazard areas. Determinations shall be undertaken by a registered design professional who shall document that the technical methods used reflect currently accepted engineering practice.
• CEBC § 2.3.1 High relevance — show source text

  R104.2.3.1 Flood hazard areas. The building official shall not grant modifications to any provisions required in flood hazard areas as established by Table R301.2 unless a determination has been made that:

  1. There is good and sufficient cause showing that the unique characteristics of the size, configuration or topography of the site render the elevation standards of Section R306 inappropriate.
  2. Failure to grant the modification would result in exceptional hardship by rendering the lot undevelopable.
  3. The granting of modification will not result in increased flood heights, additional threats to public safety or extraordinary public expense; cause fraud on or victimization of the public; or conflict with existing laws or ordinances.
  4. The modification is the minimum necessary to afford relief, considering the flood hazard.
  5. Written notice specifying the difference between the design flood elevation and the elevation to which the building is to be built, stating that the cost of flood insurance will be commensurate with the increased risk resulting from the reduced floor elevation and stating that construction below the design flood elevation increases risks to life and property, has been submitted to the applicant.

  R104.3 Applications and permits. The building official shall receive applications, review construction documents, issue permits, inspect the premises for which such permits have been issued and enforce compliance with the provisions of this code.

  R104.3.1 Determination of substantially improved or substantially damaged existing buildings in flood hazard areas. For applications for reconstruction, rehabilitation, addition, alteration, repair or other improvement of existing buildings or structures located in a flood hazard area as established by Table R301.2, the building official shall examine or cause to be examined the construction documents and shall make a determination with regard to the value of the proposed work. For buildings that have sustained damage of any origin, the value of the proposed work shall include the cost to repair the building or structure to its predamaged condition. If the building official finds that the value of proposed work equals or exceeds 50 percent of the market value of the building or structure before the damage has occurred or the improvement is started, the proposed work is a substantial improvement or repair of substantial damage and the building official shall require existing portions of the entire building or structure to meet the requirements of Section R306.

  R104.4 Right of entry. Where it is necessary to make an inspection to enforce the provisions of this code, or where the building official has reasonable cause to believe that there exists in a structure or on any premises a condition that is contrary to or in violation of this code that makes the structure or premises unsafe, dangerous or hazardous, the building official is authorized to enter the structure or premises at all reasonable times to inspect or to perform the duties imposed by this code. If such structure or premises is occupied, the building official shall present credentials to the occupant and request entry. If such structure or premises is unoccupied, the building official shall first make a reasonable effort to locate the owner, the owner’s authorized agent, or other person having charge or control of the structure or premises and request entry. If entry is refused, the building official shall have recourse to every remedy provided by law to secure entry.

  R104.4.1 Warrant. Where the building code official has first obtained a proper inspection warrant or other remedy provided by law to secure entry, an owner, the owner’s authorized agent, occupant or person having charge, care or control of the structure or premises shall not fail or neglect, after a proper request is made as herein provided, to permit entry therein by the building code official for the purposes of inspec

• CBC § G107 High relevance — show source text

  10. The costs of providing governmental services during and after flood conditions including maintenance and repair of public utilities and facilities such as sewer, gas, electrical and water systems, streets and bridges.

  G106.7 Conditions for issuance. Variances shall only be issued by the board where all of the following criteria are met:

  1. A technical showing of good and sufficient cause that the unique characteristics of the size, configuration or topography of the site renders the elevation standards inappropriate.

  2. A determination that failure to grant the variance would result in exceptional hardship by rendering the lot undevelopable.

  3. A determination that the granting of a variance will not result in increased flood heights, additional threats to public safety, extraordinary public expense, nor create nuisances, cause fraud on or victimization of the public or conflict with existing local laws or ordinances.

  4. A determination that the variance is the minimum necessary, considering the flood hazard, to afford relief.

  5. Notification to the applicant in writing over the signature of the floodplain administrator that the issuance of a variance to construct a structure below the base flood level will result in increased premium rates for flood insurance up to amounts as high as $25 for $100 of insurance coverage, and that such construction below the base flood level increases risks to life and property.

  SECTION G107—SUBDIVISIONS

  G107.1 General. Any subdivision proposal, including proposals for manufactured home parks and subdivisions, or other proposed new development in a flood hazard area shall be reviewed to verify all of the following:

  1. Such proposals are consistent with the need to minimize flood damage.
  2. Public utilities and facilities, such as sewer, gas, electric and water systems, are located and constructed to minimize or eliminate flood damage.
  3. Adequate drainage is provided to reduce exposure to flood hazards.

  G107.2 Subdivision requirements. The following requirements shall apply in the case of any proposed subdivision, including proposals for manufactured home parks and subdivisions, any portion of which lies within a flood hazard area:

  1. The flood hazard area, including floodways, coastal high-hazard areas and coastal A zones, as appropriate, shall be delineated on tentative and final subdivision plats.
  2. Design flood elevations shall be shown on tentative and final subdivision plats.
  3. Residential building lots shall be provided with adequate buildable area outside the floodway.
  4. The design criteria for utilities and facilities set forth in this appendix and appropriate International Codes shall be met.

  2025 CALIFORNIA BUILDING CODE APPENDIX G-5

  on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

  APPENDIX G—FLOOD-RESISTANT CONSTRUCTION

  SECTION G108—SITE IMPROVEMENT

  G108.1 Development in floodways. Development or land-disturbing activity shall not be authorized in the floodway unless it has been demonstrated through hydrologic and hydraulic analyses performed in accordance with standard engineering practice, and prepared by a registered design professional, that the proposed encroachment will not result in any increase in the base flood level.

  G108.2 Coastal high-hazard areas and coastal A zones. In coastal high-hazard areas and coastal A zones:

  1. New buildings and buildings that are substantially improved shall only be authorized landward of the reach of mean high tide.

  2. The use of fill for structural support of buildings is prohibited.

• CRC § G108 High relevance — show source text

  G107.2 Subdivision requirements. The following requirements shall apply in the case of any proposed subdivision, including proposals for manufactured home parks and subdivisions, any portion of which lies within a flood hazard area:

  1. The flood hazard area, including floodways, coastal high-hazard areas and coastal A zones, as appropriate, shall be delineated on tentative and final subdivision plats.
  2. Design flood elevations shall be shown on tentative and final subdivision plats.
  3. Residential building lots shall be provided with adequate buildable area outside the floodway.
  4. The design criteria for utilities and facilities set forth in this appendix and appropriate International Codes shall be met.

  2025 CALIFORNIA BUILDING CODE APPENDIX G-5

  on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

  APPENDIX G—FLOOD-RESISTANT CONSTRUCTION

  SECTION G108—SITE IMPROVEMENT

  G108.1 Development in floodways. Development or land-disturbing activity shall not be authorized in the floodway unless it has been demonstrated through hydrologic and hydraulic analyses performed in accordance with standard engineering practice, and prepared by a registered design professional, that the proposed encroachment will not result in any increase in the base flood level.

  G108.2 Coastal high-hazard areas and coastal A zones. In coastal high-hazard areas and coastal A zones:

  1. New buildings and buildings that are substantially improved shall only be authorized landward of the reach of mean high tide.

  2. The use of fill for structural support of buildings is prohibited.

  G108.3 Sewer facilities. All new or replaced sanitary sewer facilities, private sewage treatment plants (including all pumping stations and collector systems) and on-site waste disposal systems shall be designed in accordance with Chapter 7, ASCE 24, to minimize or eliminate infiltration of floodwaters into the facilities and discharge from the facilities into floodwaters, or impairment of the facilities and systems.

  G108.4 Water facilities. All new or replacement water facilities shall be designed in accordance with the provisions of Chapter 7, ASCE 24, to minimize or eliminate infiltration of floodwaters into the systems.

  G108.5 Storm drainage. Storm drainage shall be designed to convey the flow of surface waters to minimize or eliminate damage to persons or property.

  G108.6 Streets and sidewalks. Streets and sidewalks shall be designed to minimize potential for increasing or aggravating flood levels.

  SECTION G109—MANUFACTURED HOMES

  G109.1 Elevation. All new and replacement manufactured homes to be placed or substantially improved in a flood hazard area shall be elevated such that the top of the foundation for the manufactured home is at or above the design flood elevation.

  G109.2 Foundations. All new and replacement manufactured homes, including substantial improvement of existing manufactured homes, shall be placed on a permanent, reinforced foundation that is designed in accordance with Section R306 of the California Residential Code .

  G109.3 Anchoring. All new and replacement manufactured homes to be placed or substantially improved in a flood hazard area shall be installed using methods and practices that minimize flood damage. Manufactured homes shall be securely anchored to an adequately anchored foundation system to resist flotation, collapse and lateral movement. Methods of anchoring are authorized to include, but are not limited to, use of over-the-top or frame ties to ground anchors. This requirement is in addition to applicable state and local anchoring requirements for resisting wind forces.

• CEBC § 3-3 High relevance — show source text

  2025 CALIFORNIA EXISTING BUILDING CODE 3-3

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  PROVISIONS FOR ALL COMPLIANCE METHODS

  members added as part of the alteration shall comply with the California Building Code . This exception shall not apply to the following:

  1. Alterations for accessibility required by the California Building Code, Chapter 11A.

  2. Alterations that constitute substantial improvement in flood hazard areas, which shall comply with Sections 503.2, 701.3 or 1303.1.3.

  3. Structural provisions of Section 304, Chapter 5 or to the structural provisions of Sections 706, 805 and 906.

  301.3.1 Prescriptive compliance. Alterations, additions and changes of occupancy complying with Chapter 5 of this code in buildings complying with the California Fire Code shall be considered in compliance with the provisions of this code.

  Exception: Hospital buildings removed from acute care service, skilled nursing facilities, intermediate-care facilities, correctional treatment centers and acute psychiatric hospitals [OSHPD 1R, 2, 4 and 5]. The provisions of adopted sections in Chapters 3 through 5 shall control the alteration, repair and change of occupancy or function of existing structures for applications listed in Section 1.10.1, 1.10.2, 1.10.4 and 1.10.5 regulated by the Department of Health Care Access and Information/Office of Statewide Hospital Planning and Development (OSHPD). Refer to Chapter 3A for services, systems and utilities that serve OSHPD 1 buildings.

  301.3.2 Work area compliance method. A lterations, additions and changes of occupancy complying with the applicable requirements of Chapters 6 through 12 of this code shall be considered in compliance with the provisions of this code.

  301.3.3 Performance compliance method. Alterations, additions and changes of occupancy complying with Chapter 13 of this code shall be considered in compliance with the provisions of this code.

  Note: [HCD 1 & HCD 2] The provisions contained in Chapter 13 are not adopted by HCD, but may be available for adoption by a local ordinance. (See Section 1.1.11.)

  301.4 Relocated or moved buildings. Relocated or moved buildings shall comply with the requirements of Chapter 14.

  SECTION 302—GENERAL PROVISIONS

  302.1 Dangerous conditions. The code official shall have the authority to require the elimination of conditions deemed dangerous.

  302.1.1 Dangerous conditions. [BSC] Regardless of the extent of structural or nonstructural damage, the code official shall have the authority to require the elimination of conditions deemed dangerous.

  302.2 Additional codes. Alterations, repairs, additions and changes of occupancy to, or relocation of, existing buildings and structures shall comply with the provisions for alterations, repairs, additions and changes of occupancy or relocation, respectively, in this code and the California Energy Code, California Fire Code, California Mechanical Code, California Plumbing Code, California Residential Code and California Electrical Code . Where provisions of the other codes conflict with provisions of this code, the provisions of this code shall take precedence.

• CEBC § 8.2 High relevance — show source text

  STRUCTURAL DESIGN

  R = Rain load, in pounds per square foot (kN/m [2] ).

  SDSL is the roof drainage system through which water is drained from the roof when the drainage systems listed in ASCE 7 Section 8.2 (a) through (d) are blocked or not working.

  TABLE 1611.1—DESIGN STORM RETURN PERIOD BY RISK CATEGORY	Col2
  RISK CATEGORY	DESIGN STORM RETURN PERIOD
  I & II	100 years
  III	200 years
  IV	500 years

  1611.2 Ponding instability. Ponding instability on roofs shall be evaluated in accordance with ASCE 7.

  1611.3 Controlled drainage. Roofs equipped with hardware to control the rate of drainage shall be equipped with a secondary drainage system at a higher elevation that limits accumulation of water on the roof above that elevation. Such roofs shall be designed to sustain the load of rainwater that will accumulate on them to the elevation of the secondary drainage system plus the uniform load caused by water that rises above the inlet of the secondary drainage system at its design flow determined from Section 1611.1. Such roofs shall be checked for ponding instability in accordance with Section 1611.2.

  SECTION 1612—FLOOD LOADS

  1612.1 General. Within flood hazard areas as established in Section 1612.3, all new construction of buildings, structures and portions of buildings and structures, including substantial improvement and restoration of substantial damage to buildings and structures, shall be designed and constructed to resist the effects of flood hazards and flood loads. For buildings that are located in more than one flood hazard area, the provisions associated with the most restrictive flood hazard area shall apply.

  1612.2 Design and construction. The design and construction of buildings and structures located in flood hazard areas, including coastal high hazard areas and coastal A zones, shall be in accordance with Chapter 5 of ASCE 7 and ASCE 24. Elevators, escalators, conveying systems and their components shall conform to ASCE 24 and ASME A17.1/CSA B44 as applicable.

  Exception: Temporary structures complying with Section 3103.6.1.3.

  1612.3 Establishment of flood hazard areas. To establish flood hazard areas, the applicable governing authority shall adopt a flood hazard map and supporting data. The flood hazard map shall include, at a minimum, areas of special flood hazard as identified by the Federal Emergency Management Agency in an engineering report entitled “The Flood Insurance Study for [ INSERT NAME OF JURISDIC -

  TION ],” dated [ INSERT DATE OF ISSUANCE ], as amended or revised with the accompanying Flood Insurance Rate Map (FIRM) and Flood Boundary and Floodway Map (FBFM) and related supporting data along with any revisions thereto. The adopted flood hazard map and supporting data are hereby adopted by reference and declared to be part of this section.

  Exception: [OSHPD 1R, 2 & 5] The flood hazard map shall include, at a minimum, areas of special flood hazard as identified by the Federal Emergency Management Agency’s Flood Insurance Study (FIS) adopted by the local authority having jurisdiction where the project is located.

• CEBC § 1011.11 High relevance — show source text

  2. Drift limits based on original design code shall be permitted to be used in lieu of the drift limits required by ASCE 7.

  SECTION 503 A —ALTERATIONS

  503 A .1 General. Alterations to any building or structure shall comply with the requirements of the California Building Code for new construction. Alterations shall be such that the existing building or structure is not less complying with the provisions of the Califor- nia Building Code than the existing building or structure was prior to the alteration.

  Exceptions:

  1. An existing stairway shall not be required to comply with the requirements of Section 1011 of the California Building Code where the existing space and construction does not allow a reduction in pitch or slope.
  2. Handrails otherwise required to comply with Section 1011.11 of the California Building Code shall not be required to comply with the requirements of Section 1014.7 of the California Building Code regarding full extension of the handrails where such extensions would be hazardous because of plan configuration.

  503 A .2 Flood hazard areas. For buildings and structures in flood hazard areas established in Section 1612 A .3 of the California Build- ing Code, any alteration that constitutes substantial improvement of the existing structure , as defined in Chapter 2, shall comply with the flood design requirements for new construction, and all aspects of the existing structure shall be brought into compliance with the requirements for new construction for flood design.

  For buildings and structures in flood hazard areas established in Section 1612 A .3 of the California Building Code any alterations that do not constitute substantial improvement of the existing structure , as defined in Chapter 2, are not required to comply with the flood design requirements for new construction.

  503 A .3 Existing structural elements carrying gravity load. Any existing gravity load-carrying structural element for which an alteration causes an increase in design dead, live or snow load, including snow drift effects, of more than 5 percent shall be replaced or altered as needed to carry the gravity loads required by the California Building Code for new structures. Any existing gravity loadcarrying structural element whose gravity load-carrying capacity is decreased as part of the alteration shall be shown to have the capacity to resist the applicable design dead, live and snow loads including snow drift effects required by the California Building Code for new structures.

  503 A .4 Existing structural elements carrying lateral load. Except as permitted by Section 503 A .13, where the alteration increases design lateral loads, results in a prohibited structural irregularity as defined in the California Building Code, ASCE 7, or decreases the

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  PRESCRIPTIVE COMPLIANCE METHOD

  capacity of any existing lateral load-carrying structural element, the lateral force-resisting system of the altered building or structure shall meet the requirements of Section s 1609 A and 1613A of the California Building Code .

  Exceptions: For incidental and minor alterations:

  1. Any existing lateral load-carrying structural element whose demand-capacity ratio with the alteration considered is not more than 10 percent greater than its demand-capacity ratio with the alteration ignored shall be permitted to remain unaltered.
• California Existing Building Code High relevance — show source text

  G106.5 Restrictions. The board shall not issue a variance for any proposed development in a floodway if any increase in flood levels would result during the base flood discharge.

  G106.6 Considerations. In reviewing applications for variances, the board shall consider all technical evaluations, all relevant factors, all other portions of this appendix and the following:

  1. The danger that materials and debris may be swept onto other lands resulting in further injury or damage.

  2. The danger to life and property due to flooding or erosion damage.

  3. The susceptibility of the proposed development, including contents, to flood damage and the effect of such damage on current and future owners.

  4. The importance of the services provided by the proposed development to the community.

  5. The availability of alternate locations for the proposed development that are not subject to flooding or erosion.

  6. The compatibility of the proposed development with existing and anticipated development.

  7. The relationship of the proposed development to the comprehensive plan and flood plain management program for that area.

  8. The safety of access to the property in times of flood for ordinary and emergency vehicles.

  9. The expected heights, velocity, duration, rate of rise and debris and sediment transport of the floodwaters and the effects of wave action, if applicable, expected at the site.

  10. The costs of providing governmental services during and after flood conditions including maintenance and repair of public utilities and facilities such as sewer, gas, electrical and water systems, streets and bridges.

  G106.7 Conditions for issuance. Variances shall only be issued by the board where all of the following criteria are met:

  1. A technical showing of good and sufficient cause that the unique characteristics of the size, configuration or topography of the site renders the elevation standards inappropriate.

  2. A determination that failure to grant the variance would result in exceptional hardship by rendering the lot undevelopable.

  3. A determination that the granting of a variance will not result in increased flood heights, additional threats to public safety, extraordinary public expense, nor create nuisances, cause fraud on or victimization of the public or conflict with existing local laws or ordinances.

  4. A determination that the variance is the minimum necessary, considering the flood hazard, to afford relief.

  5. Notification to the applicant in writing over the signature of the floodplain administrator that the issuance of a variance to construct a structure below the base flood level will result in increased premium rates for flood insurance up to amounts as high as $25 for $100 of insurance coverage, and that such construction below the base flood level increases risks to life and property.

  SECTION G107—SUBDIVISIONS

  G107.1 General. Any subdivision proposal, including proposals for manufactured home parks and subdivisions, or other proposed new development in a flood hazard area shall be reviewed to verify all of the following:

  1. Such proposals are consistent with the need to minimize flood damage.
  2. Public utilities and facilities, such as sewer, gas, electric and water systems, are located and constructed to minimize or eliminate flood damage.
  3. Adequate drainage is provided to reduce exposure to flood hazards.
• CEBC § 104.2.4.1 High relevance — show source text

  [A] 104.2.4.1 Flood hazard areas. The building official shall not grant modifications to any provision required in flood hazard areas as established by Section 1612.3 unless a determination has been made that:

  1. A showing of good and sufficient cause that the unique characteristics of the size, configuration or topography of the site render the elevation standards of Section 1612 inappropriate.

  2. A determination that failure to grant the variance would result in exceptional hardship by rendering the lot undevelopable.

  3. A determination that the granting of a variance will not result in increased flood heights, additional threats to public safety or extraordinary public expense; cause fraud on or victimization of the public; or conflict with existing laws or ordinances.

  4. A determination that the variance is the minimum necessary to afford relief, considering the flood hazard.

  5. Submission to the applicant of written notice specifying the difference between the design flood elevation and the elevation to which the building is to be built, stating that the cost of flood insurance will be commensurate with the increased risk resulting from the reduced floor elevation, and stating that construction below the design flood elevation increases risks to life and property.

  [A] 104.3 Applications and permits. The building official shall receive applications, review construction documents, issue permits, inspect the premises for which such permits have been issued and enforce compliance with the provisions of this code.

  [A] 104.3.1 Determination of substantially improved or substantially damaged existing buildings and structures in flood hazard areas. For applications for reconstruction, rehabilitation, repair, alteration, addition or other improvement of existing buildings or structures located in flood hazard areas, the building official shall determine if the proposed work constitutes substantial improvement or repair of substantial damage. Where the building official determines that the proposed work constitutes substantial improvement or repair of substantial damage, and where required by this code, the building official shall require the building to meet the requirements of Section 1612, or Section R306 of the California Residential Code, as applicable.

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  ADMINISTRATION

  [A] 104.4 Right of entry. Where it is necessary to make an inspection to enforce the provisions of this code, or where the building official has reasonable cause to believe that there exists in a structure or on a premises a condition that is contrary to or in violation of this code that makes the structure or premises unsafe, dangerous or hazardous, the building official is authorized to enter the structure or premises at all reasonable times to inspect or to perform the duties imposed by this code. If such structure or premises is occupied, the building official shall present credentials to the occupant and request entry. If such structure or premises is unoccupied, the building official shall first make a reasonable effort to locate the owner, the owner’s authorized agent or other person having charge or control of the structure or premises and request entry. If entry is refused, the building official shall have recourse to every remedy provided by law to secure entry.

  [A] 104.4.1 Warrant. Where the building official has first obtained a proper inspection warrant or other remedy provided by law to secure entry, an owner, the owner’s authorized agent, occupant or person having charge, care or control of the structure or premises shall not fail or neglect, after a proper request is made as herein provided, to permit entry therein by the building official for the purposes of inspection and examination pursuant to this code.

• CEBC § 1612.3.2 High relevance — show source text

  source.

  2. Determine the design flood elevation or floodway in accordance with accepted hydrologic and hydraulic engineering practices used to define special flood hazard areas. Determinations shall be undertaken by a registered design professional who shall document that the technical methods used reflect currently accepted engineering practice.

  1612.3.2 Determination of impacts. In riverine flood hazard areas where design flood elevations are specified but floodways have not been designated, the applicant shall provide a floodway analysis that demonstrates that the proposed work will not increase the design flood elevation more than 1 foot (305 mm) at any point within the jurisdiction of the applicable governing authority.

  1612.4 Flood hazard documentation. The following documentation shall be prepared and sealed by a registered design professional and submitted to the building official:

  1. For construction in flood hazard areas other than coastal high hazard areas or coastal A zones: 1.1. The elevation of the lowest floor, including the basement, as required by the lowest floor elevation inspection in Section 110.3.3 and for the final inspection in Section 110.3.12.1. 1.2. For fully enclosed areas below the design flood elevation where provisions to allow for the automatic entry and exit of floodwaters do not meet the minimum requirements in Section 2.7.2.1 of ASCE 24, construction documents shall include a statement that the design will provide for equalization of hydrostatic flood forces in accordance with Section 2.7.2.2 of ASCE 24.

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  STRUCTURAL DESIGN

  1.3. For dry floodproofed nonresidential buildings, construction documents shall include a statement that the dry floodproofing is designed in accordance with ASCE 24 and shall include the flood emergency plan specified in Chapter 6 of ASCE 24. 1.4. For dry floodproofed nonresidential buildings, the elevation to which the building is dry floodproofed as required for the final inspection in Section 110.3.12.1. 2. For construction in coastal high hazard areas and coastal A zones: 2.1. The elevation of the bottom of the lowest horizontal structural member as required by the lowest floor elevation inspection in Section 110.3.3 and for the final inspection in Section 110.3.12.1. 2.2. Construction documents shall include a statement that the building is designed in accordance with ASCE 24, including that the pile or column foundation and building or structure to be attached thereto is designed to be anchored to resist flotation, collapse and lateral movement due to the effects of wind and flood loads acting simultaneously on all building components, and other load requirements of Chapter 16. 2.3. For breakaway walls designed to have a resistance of more than 20 psf (0.96 kN/m [2] ) determined using allowable stress design or a resistance to an ultimate load of more than 33 pounds per square foot (1.58 kN/m [2] ), construction documents shall include a statement that the breakaway wall is designed in accordance with ASCE 24. 2.4 For breakaway walls where provisions to allow for the automatic entry and exit of floodwaters do not meet the minimum requirements in Section 2.7.2.1 of ASCE 24, construction documents shall include a statement that the design will provide for equalization of hydrostatic flood forces in accordance with Section 2.7.2.2 of ASCE 24.

  SECTION 1613—EARTHQUAKE LOADS