Additions — new-construction requirements and integration with existing building

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

• CEBC § 1101.5 High relevance — show source text

  1|||X|||||||||||||||||||||| |1101.5|||X|†|†|||||||||||||||||||| |1101.6||||†|†|||||||||||||||||||| |1102.2|||X|||||||||||||||||||||| |1102.3 Exception||||†|†|||||||||||||||||||| |1102.4|||X||||||||||||||||||||||

  The state agency does not adopt sections identified with the following symbol: The Office of the State Fire Marshal’s adoption of this chapter or individual sections is applicable to structures regulated by other state agencies pursuant to Section 1.11.

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  11 ADDITIONS

  User notes:

  About this chapter: Chapter 11 provides the requirements for additions, which correlate to the code requirements for new construction. There are, however, some exceptions that are specifically stated within this chapter. An “Addition” is defined in Chapter 2 as “an extension or increase in the floor area, number of stories or height of a building or structure.” Chapter 11 contains the minimum requirements for an addition that is not separated from the existing building by a fire wall.

  SECTION 1101—GENERAL

  1101.1 Scope. An addition to a building or structure shall comply with the California Building Standards Codes as adopted for new construction without requiring the existing building or structure to comply with any requirements of those codes or of these provisions, except as required by this chapter. Where an addition or alteration impacts the existing building or structure, the result of the addition or alteration shall not put the existing building or structure out of compliance with the California Building or Residential Code as applicable. The provisions of height and area of the California Building or Residential Code shall apply to the entire existing building with the additions.

  1101.2 Creation or extension of nonconformity. An addition shall not create or extend any nonconformity in the existing building to which the addition is being made with regard to accessibility, structural strength, supports and attachments for nonstructural components, fire safety, means of egress or the capacity of mechanical, plumbing or electrical systems.

  Exception: Nonconforming supports and attachments for nonstructural components that serve the addition from within the existing building need not be altered to comply with California Building Code Section 1613 unless the components are part of the addition’s life safety system or are required to serve an addition assigned to Risk Category IV.

  [BS] 1101.3 Risk category assignment. Where the addition and the existing building have different occupancies, the risk category of each existing and added occupancy shall be determined in accordance with Section 1604.5.1 of the California Building Code . Where application of that section results in a higher risk category for the existing building compared with the risk category for the existing building before the addition, such a change shall be considered a change of occupancy and shall comply with Chapter 10 of this code. Where application of that section results in a higher risk category for the addition compared with the risk category for the addition by itself, the addition and any systems in the existing building required to serve the addition shall comply with the requirements of the California Building Code for new construction for the higher risk category.

• CEBC § 502.1.1 High relevance — show source text

  502.1.1 Risk category assignment. Where the addition and the existing building have different occupancies, the risk category of each existing and added occupancy shall be determined in accordance with Section 1604.5.1 of the California Building Code . Where application of that section results in a higher risk category for the existing building compared with the risk category for the existing building before the addition, such a change shall be considered a change of occupancy and shall comply with Section 506 of this code. Where application of that section results in a higher risk category for the addition compared with the risk category for the addition by itself, the addition and any systems in the existing building required to serve the addition shall comply with the requirements of the California Building Code for new construction for the higher risk category.

  502.1.2 Creation or extension of nonconformity. An addition shall not create or extend any nonconformity in the existing building to which the addition is being made with regard to accessibility, structural strength, supports and attachments for nonstructural components, fire safety, means of egress or the capacity of mechanical, plumbing or electrical systems.

  Exception: Nonconforming supports and attachments for nonstructural components that serve the addition from within the existing building need not be altered to comply with California Building Code Section 1613 unless the components are part of the addition’s life-safety system or are required to serve an addition assigned to Risk Category IV.

  [BS] 502.2 Flood hazard areas. For buildings and structures in flood hazard areas established in Section 1612.3 of the California Building Code, or Section R322 of the California Residential Code, as applicable, any addition that constitutes substantial improvement of the existing structure 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 new foundations, foundations raised or extended upward, and replacement foundations, the foundations shall be in compliance with the requirements for new construction for flood design.

  For buildings and structures in flood hazard areas established in Section 1612.3 of the California Building Code, or Section R322 of the California Residential Code, as applicable, any additions that do not constitute substantial improvement of the existing structure are not required to comply with the flood design requirements for new construction, provided that both of the following apply:

  1. The addition shall not create or extend a nonconformity of the existing building or structure with the flood-resistant construction requirements.
  2. The lowest floor of the addition shall be at or above the lower of the lowest floor of the existing building or structure or the lowest floor elevation required in Section 1612 of the California Building Code or Section R306 of the California Residential Code, as applicable.

  [BS] 502.3 Existing structural elements carrying gravity load. Any existing gravity load-carrying structural element for which an addition and its related alterations cause 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 load-carrying structural element whose vertical load-carrying capacity is decreased as part of the addition and its related alterations shall be considered to be an altered element subject to the requirements of Section 503.3. Any existing element that will form part of the lateral load path for any part of the addition shall be considered to be an existing lateral load-carrying structural element subject to the requirements o

• CEBC § 1302.1.3 High relevance — show source text

  1302.1.3 Additions. Additions to existing buildings shall comply with the requirements of the International Building Code or the International Residential Code for new construction. The combined height and area of the existing building and the new addition shall not exceed the height and area allowed by Chapter 5 of the International Building Code . Where a fire wall that complies with Section 706 of the International Building Code is provided between the addition and the existing building, the addition shall be considered a separate building. Where a new occupiable roof is added to a building or structure, the occupiable roof shall comply with the provisions of the International Building Code .

  Exception: In-filling of floor openings and nonoccupiable appendages, such as elevator and exit stairway shafts, shall be permitted beyond that permitted by the International Building Code .

  1302.1.4 Alterations. An existing building or portion thereof shall not be altered in such a manner that results in the building being less safe or sanitary than such building is currently.

  Exception: Where the current level of safety or sanitation is proposed to be reduced, the portion altered shall conform to the requirements of the International Building Code .

  1302.1.5 Escalators. Where escalators are provided in below-grade transportation stations, existing and new escalators shall be permitted to have a clear width of less than 32 inches (815 mm).

  1302.1.6 Plumbing fixtures. Plumbing fixtures shall be provided in accordance with Section 1009 for a change of occupancy and Section 808 for alterations. Plumbing fixtures for additions shall be in accordance with the International Plumbing Code .

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  PERFORMANCE COMPLIANCE METHODS

  SECTION 1303—ACCEPTANCE

  1303.1 General. For repairs, alterations, additions and changes of occupancy to existing buildings that are evaluated in accordance with this section, compliance with this section shall be accepted by the code official.

  1303.1.1 Hazards. Where the code official determines that an unsafe condition exists as provided for in Section 115, such unsafe condition shall be abated in accordance with Section 115.

  1303.1.2 Compliance with other codes. Buildings that are evaluated in accordance with this section shall comply with the Inter- national Fire Code and International Property Maintenance Code .

  [BS] 1303.1.3 Compliance with flood hazard provisions. In flood hazard areas, buildings that are evaluated in accordance with this section shall comply with Section 1612 of the International Building Code, or Section R306 of the International Residential Code, as applicable, if the work covered by this section constitutes substantial improvement. If the work covered by this section is a structurally connected horizontal addition that does not constitute substantial improvement, the addition is not required to comply with the flood design requirements for new construction, provided that both of the following apply.

  1. The addition shall not create or extend any nonconformity of the existing building with the flood-resistant construction requirements.
  2. The lowest floor of the addition shall be at or above the lower of the lowest floor of the existing building or the lowest floor elevation required in Section 1612 of the International Building Code or Section R306 of the International Residential Code, as applicable.

  SECTION 1304—INVESTIGATION AND EVALUATION

• CEBC § 304.3.1 High relevance — show source text

  Exceptions:

  1. Buildings of Group R occupancy with not more than five dwelling or sleeping units used solely for residential purposes where the existing building and the addition comply with the conventional light-frame construction methods of the Cali- fornia Building Code or the provisions of the California Residential Code .
  2. Any existing lateral load-carrying structural element whose demand-capacity ratio with the addition considered is not more than 10 percent greater than its demand-capacity ratio with the addition ignored shall be permitted to remain unaltered. For purposes of calculating demand-capacity ratios, the demand shall consider applicable load combinations with design lateral loads or forces in accordance with Section 1609 of the California Building Code and Section 304.3.1 of this code . For purposes of this exception, comparisons of demand-capacity ratios and calculation of design lateral loads, forces and capacities shall account for the cumulative effects of additions and alterations since original construction.

  When calculating demand-capacity ratios for wind, the date of original construction shall be permitted to be taken as the date of completion of a prior addition, alteration or repair in compliance with Section 1609 of the California Building Code or the code wind forces in effect at the time. When calculating demand-capacity ratios for earthquake, the date of original construction shall be permitted to be taken as the date of completion of a prior addition, alteration or repair in compliance with Section 304.3.1 or the full seismic forces in effect at the time.

  [BS] 1103.3 Flood hazard areas. Additions and foundations in flood hazard areas shall comply with the following requirements:

  1. For horizontal additions that are structurally interconnected to the existing building: 1.1. If the addition and all other proposed work, when combined, constitute substantial improvement, the existing building and the addition shall comply with Section 1612 of the California Building Code, or Section R306 of the California Residential Code, as applicable. 1.2. If the addition constitutes substantial improvement, the existing building and the addition shall comply with Section 1612 of the California Building Code, or Section R306 of the California Residential Code, as applicable. 1.3. If the addition does not constitute substantial improvement, the addition is not required to comply with the flood design requirements for new construction, provided that both of the following apply: 1.3.1. The addition shall not create or extend any nonconformity of the existing building with the flood-resistant construction requirements. 1.3.2. The lowest floor of the addition shall be at or above the lower of the lowest floor of the existing building or the lowest floor elevation required in Section 1612 of the California Building Code, or Section R306 of the California Residential Code, as applicable.
  2. For horizontal additions that are not structurally interconnected to the existing building: 2.1. The addition shall comply with Section 1612 of the California Building Code, or Section R306 of the California Resi- dential Code, as applicable. 2.2. If the addition and all other proposed work, when combined, constitute substantial improvement, the existing building and the addition shall comply with Section 1612 of the California Building Code, or Section R306 of the California Residential Code, as applicable.
  3. For vertical additions and all other proposed work that, when combined, constitute substantial improvement, the existing building shall comply with Section 1612 of the California Building Code, or Section R306 of the California Residential Code, as applicable.
• CEBC § 317.2 High relevance — show source text

  317.2 Scope. All alterations, structurally connected additions and/or repairs to existing structures or portions thereof shall, at a minimum, be designed and constructed to resist the effects of seismic ground motions as provided in this section. The structural system shall be evaluated by a registered design professional and, if not meeting or exceeding the minimum seismic design performance requirements of this section, shall be retrofitted in compliance with these requirements.

  Exception: Those structures for which Section 317.3 determines that assessment is not required, or for which Section 317.4 determines that retrofit is not needed, then only the requirements of Section 317.11 apply.

  317.3 Applicability.

  317.3.1 Existing state-owned buildings. [BSC, DSA-SS] For existing state-owned structures including all buildings owned by the University of California and the California State University, the requirements of Section 317 apply whenever the structure is to be retrofitted, repaired or modified and any of the following apply: 1. Total construction cost, not including cost of furnishings, fixtures and equipment, or normal maintenance, for the building exceeds 25 percent of the construction cost for the replacement of the existing building. The changes are cumulative for past modifications to the building that occurred after adoption of the 1995 California Building Code and did not require seismic retrofit.

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  PROVISIONS FOR ALL COMPLIANCE METHODS

  2. There are changes in risk category. 3. The modification to the structural components increases the seismic forces in or strength requirements of any structural component of the existing structure by more than 10 percent cumulative since the original construction, unless the component has the capacity to resist the increased forces determined in accordance with Section 319. If the building’s seismic base shear capacity has been increased since the original construction, the percent change in base shear may be calculated relative to the increased value.

  4. Structural elements need repair where the damage has reduced the lateral-load-resisting capacity of the structural system by more than 10 percent. 5. Changes in live or dead load increase story shear by more than 10 percent.

  317.3.2 Public school buildings. [DSA-SS] For public schools, the provisions of Section 317 apply when required in accordance with Sections 4-307 and 4-309(c) of the California Administrative Code.

  317.3.3 Community college buildings. [DSA-SS/CC] For community colleges, the provisions of Section 317 apply when required in accordance with Sections 4-307 and 4-309(c) of the California Administrative Code.

  317.4 Evaluation required. If the criteria in Section 317.3 apply to the project under consideration, the design professional of record shall provide an evaluation in accordance with Section 317 to determine the seismic performance of the building in its current configuration and condition. If the structure's seismic performance as required by Section 317.5 is evaluated as satisfactory and the peer reviewer(s), when Method B of Section 321 is used, concur, then no structural retrofit is required.

  _**317.5 Minimum seismic design performance levels for structural and nonstructural components.

• CEBC § 1.3 High relevance — show source text

  SECTION BO106—ADDITION

  BO106.1 General. Where existing buildings with the addition are within the scope of this code, additions shall comply with this section and other applicable provisions of this code for new construction or as permitted by this appendix. Engineered design in accordance with Section R301.1.3 shall be permitted to meet the requirements of this section.

  BO106.2 Structure for horizontal additions. Where an addition involves new construction attached to an existing building, the new construction shall meet all of the structural requirements of this code for new construction. Alterations to the existing building shall comply with the requirements governing alterations within this code. In wood light-frame additions, connection of the structural components shall be permitted to be provided using wall top plates and addition studs that abut the existing building. Wall top plates shall be lapped and spliced in accordance with Section R602.3.2. Abutting studs shall be fastened in accordance with Table R602.3(1).

  Exception: The addition structure shall be permitted to be connected to the existing building in accordance with accepted engineering practice.

  BO106.3 Structure for vertical additions. Where an addition involves new construction that adds a story to any part of the existing building or vertically increases the height of any part of the existing building, the new construction and the existing building together shall be shown to comply with, or altered to comply with, all of the structural requirements of this code for new construction.

  Exception: Where the new structure and the existing structure together are evaluated in accordance with accepted engineering practice and are shown to be sufficient to support the combined loads from the new structure and existing structure, no structural alterations are required.

  SECTION BO107—RELOCATED BUILDINGS

  BO107.1 General. Residential buildings or structures moved into or within the jurisdiction are not required to comply with the requirements for new construction under this code, provided they comply with all of the following conditions:

  1. The building shall be safe for human occupancy as determined by the California Fire Code and the International Property Maintenance Code .

  2. Any repair, alteration or change of use undertaken within the relocated structure shall comply with the requirements of this code applicable to the work being performed.

  3. Any field fabricated elements shall comply with the applicable requirements of this code.

  SECTION BO108—REFERENCED STANDARDS

  BO108.1 General. See Table BO108.1 for standards that are referenced in various sections of this appendix. Standards are listed by the standard identification with the effective date, the standard title and the section or sections of this appendix that reference the standard.

  TABLE BO108.1—REFERENCED STANDARDS	Col2	Col3
  STANDARD ACRONYM	STANDARD NAME	SECTION HEREIN REFERENCED
  CEBC—25	California Existing Building Code	BO102.8
  CFC—25	California Fire Code	BO107.1
  IPMC—24	International Property Maintenance Code®	BO107.1

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  CA RESERVED

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  APPENDIX CA-2 2025 CALIFORNIA RESIDENTIAL CODE

• CEBC § 501A.3 High relevance — show source text

  501 A .2 Fire-resistance ratings. Fire-resistance ratings shall comply with the California Building Standards Code.

  501A.3 Prescriptive compliance provisions. Alterations, additions and changes of occupancy to the following categories of existing buildings and structures shall comply with the provisions of this section.

  501A.3.1 Prescriptive compliance provisions for SPC-4D using the California Building Code, 1980 (CBC 1980). Nonconforming buildings shall satisfy the following requirements: 1. The California Building Code, 1980 (CBC 1980), as used in this chapter, consists of the Uniform Building Code, 1979 (UBC 1979) along with requirements contained in: a) California Code of Regulations, Title 24- Building Standards, dated February 2, 1980 (Revision record for Register 80, No. 5). b) California Code of Regulations, Title 22 – Social Security, dated October 13, 1979 (Revision Record for Register 79, No 41). c) California Code of Regulations, Title 17 – Public Health, dated October 13, 1979 (Revision Record for Register 79, No 41-B). 2. All existing structural elements of Seismic Force Resisting System (SFRS) shall satisfy the detailing requirements in the CBC 1980 or demonstrate that the level of seismic performance is equivalent to that given in the CBC 1980, as determined by the building official. 3. A continuous load path or paths with adequate strength and stiffness to transfer all the forces from the point of origin to final point of resistance shall be justified by analysis. 4. Site data report in accordance with the CBC 1980 shall establish that seismically induced differential settlement does not exceed 1 ″ in 40 ′ .

  5. Adjacent buildings shall satisfy the SPC building separation requirements in accordance with the California Administrative Code, Chapter 6 Section 3.4. 6. The addition of new structural elements or strengthening of existing structural elements for retrofit of nonconforming build- ings to SPC-4D shall comply with the following: a) The seismic demand (forces or displacements) shall be in accordance with the CBC 1980; b) Capacity, detailing and connections for new structural elements shall satisfy the requirements in the CBC 2025 for new construction; and c) The strengthening of existing structural elements shall use capacities determined in accordance with the CBC 2025 for new construction consistent with the detailing and connections used in the strengthened member. 7. All construction, quality assurance and quality control shall be in accordance with the new construction provisions of CBC 2025.

  8. Elements not part of the Seismic Force-Resisting System (SFRS), including those identified in the California Administrative Code Chapter 6, Article 10, shall be evaluated using seismic forces and the requirements of the CBC 1980. 9. Any column or wall that forms part of two or more intersecting SFRS and is subjected to axial load due to seismic forces acting along either principal plan axis equaling or exceeding 20 percent of the axial design strength of the column or wall shall be _evaluated for the most critical load effect due to application of seismic force in any direction.

• CEBC § 5A-4 High relevance — show source text

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  PRESCRIPTIVE COMPLIANCE METHOD

  the requirements for new construction for flood design. For new foundations, foundations raised or extended upward, and replacement foundations, the foundations shall be in compliance with the requirements for new construction for flood design.

  For buildings and structures in flood hazard areas established in California Building Code, Section 1612 A .3, any additions 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, provided that both of the following apply:

  1. The addition shall not create or extend a nonconformity of the existing building or structure with the flood-resistant construction requirements.
  2. The lowest floor of the addition shall be at or above the lower of the lowest floor of the existing building or structure or the lowest floor elevation required in Section 1612 A of the California Building Code .

  502 A .3 Existing structural elements carrying gravity load. Any existing gravity load-carrying structural element for which an addition and its related alterations cause 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 load-carrying structural element whose vertical load-carrying capacity is decreased as part of the addition and its related alterations shall be considered to be an altered element subject to the requirements of Section 503 A .3. Any existing element that will form part of the lateral load path for any part of the addition shall be considered to be an existing lateral load-carrying structural element subject to the requirements of Section 502A.4 .

  502 A .4 Existing structural elements carrying lateral load. Where the addition is structurally independent of the existing structure, existing lateral load-carrying structural elements shall be permitted to remain unaltered. Where the addition is not structurally independent of the existing structure, the lateral force-resisting system of the existing structure and its addition acting together as a single structure shall comply with Section 1609 A and 1613A of the California Building Code .

  Exceptions: For incidental and minor additions:

  1. Any existing lateral load-carrying structural element whose demand-capacity ratio with the addition considered is not more than 10 percent greater than its demand-capacity ratio with the addition ignored shall be permitted to remain unaltered. For purposes of calculating demand-capacity ratios, the demand shall consider applicable load combinations with design lateral loads or forces in accordance with Sections 1609 A and 1613 A of the California Building Code . For purposes of this exception, comparisons of demand-capacity ratios and calculation of design lateral loads, forces and capacities shall account for the cumulative effects of additions and alterations since original construction. When calculating demand-capacity ratios for wind, the date of original construction shall be permitted to be taken as the date of completion of a prior addition, alteration or repair in compliance with Section 1609 A of the California Building Code or the code wind forces in effect at the time.
• CEBC § 7.12 High relevance — show source text

  SECTION 303 A — RESERVED

  SECTION 304 A —STRUCTURAL DESIGN LOADS AND EVALUATION AND DESIGN PROCEDURES

  304 A .1 Live loads. Where an addition or alteration does not result in increased design live load, existing gravity load-carrying structural elements shall be permitted to be evaluated and designed for live loads approved prior to the addition or alteration. If the approved live load is less than that required by Section 1607 A of the California Building Code, the area designated for the nonconforming live load shall be posted with placards of approved design indicating the approved live load. Where the addition or alteration results in increased design live load, the live load required by Section 1607 A of the California Building Code shall be used.

  304 A .2 Snow loads on adjacent buildings. Where an alteration or addition changes the potential snow drift effects on an adjacent building, the code official is authorized to enforce Section 7.12 of ASCE 7.

  304 A .3 Additions, alterations, repairs and seismic retrofit to existing buildings or structures.

  304 A .3.1 Structures designed in accordance with pre-1973 building code. Provisions of this section shall apply to hospital build- ings which were originally designed to pre-1973 building codes and not designated as SPC 3 or higher in accordance with Chapter 6 of the California Administrative Code.

  304A.3.1.1 Incidental and minor structural alteration, additions, or repairs. Incidental and minor structural additions shall be permitted, provided the additions meet the California Building Code for new construction using importance factor, I e , equal to or greater than 1.0. Alterations or repair to existing gravity and lateral force-resisting systems shall be made to conform to the requirements of Section 503A or Chapter 4A, respectively, using importance factor, I e , equal to or greater than 1.0. 1. Nonstructural components. Component importance factor, I p , shall be permitted to be 1.0.

  Exception: Components required for life-safety purposes after an earthquake, including emergency and standby power systems, mechanical smoke removal systems, fire protection sprinkler systems, fire alarm control panels and egress stairways shall have a component importance factor (I p ) of 1.5.

  304A.3.1.2 Major structural alteration, additions or repairs. Major structural alterations, additions or repairs shall be in accor- dance with Section 304A.3.4.1 or 304A.3.4.3 as applicable.

  304A.3.2 Seismic evaluation and retrofit of general acute care hospitals for compliance with the California Administrative Code, Chapter 6. Notwithstanding any other requirements of this code, existing general acute care hospitals shall comply with the seismic evaluation requirements specified in Chapter 6, of the California Administrative Code, when applicable. Seismic retrofit to comply with requirements specified in Chapter 6 of the California Administrative Code shall be permitted to be in accordance with these provisions. When load combinations which do not include seismic forces are required, the new building provisions of this code shall be applicable.

• CEBC § 8.1 High relevance — show source text

  BO105.8 Stairs, handrails and guards. Stairs, handrails and guards shall comply with this section.

  BO105.8.1 Stair width. Existing basement stairs and handrails not otherwise being altered or modified shall be permitted to maintain their current clear width at, above and below existing handrails.

  BO105.8.2 Stair headroom. Headroom height on existing basement stairs being altered or modified shall not be reduced below the existing stairway finished headroom. Existing basement stairs not otherwise being altered shall be permitted to maintain the current finished headroom.

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  APPENDIX BO — EXISTING BUILDINGS AND STRUCTURES

  BO105.8.3 Stair landing. Landings serving existing basement stairs being altered or modified shall not be reduced below the existing stairway landing depth and width. Existing basement stairs not otherwise being altered shall be permitted to maintain the current landing depth and width.

  BO105.8.4 Stair treads and risers. An existing stairway shall not be required to comply with Section R318.7.5 where the existing space and construction does not allow a reduction in pitch or slope. Where risers are added to an existing stair, the tread and riser dimension of the added risers shall match the existing stair.

  BO105.8.5 Stairway illumination. Stairways within the work area shall be provided with illumination in accordance with Section R325.7.

  BO105.8.6 Handrails and guards. If a stair or any portion of a stair is altered, a handrail and guard, where required, shall be provided in accordance with Sections R318 and R320.

  SECTION BO106—ADDITION

  BO106.1 General. Where existing buildings with the addition are within the scope of this code, additions shall comply with this section and other applicable provisions of this code for new construction or as permitted by this appendix. Engineered design in accordance with Section R301.1.3 shall be permitted to meet the requirements of this section.

  BO106.2 Structure for horizontal additions. Where an addition involves new construction attached to an existing building, the new construction shall meet all of the structural requirements of this code for new construction. Alterations to the existing building shall comply with the requirements governing alterations within this code. In wood light-frame additions, connection of the structural components shall be permitted to be provided using wall top plates and addition studs that abut the existing building. Wall top plates shall be lapped and spliced in accordance with Section R602.3.2. Abutting studs shall be fastened in accordance with Table R602.3(1).

  Exception: The addition structure shall be permitted to be connected to the existing building in accordance with accepted engineering practice.

  BO106.3 Structure for vertical additions. Where an addition involves new construction that adds a story to any part of the existing building or vertically increases the height of any part of the existing building, the new construction and the existing building together shall be shown to comply with, or altered to comply with, all of the structural requirements of this code for new construction.

  Exception: Where the new structure and the existing structure together are evaluated in accordance with accepted engineering practice and are shown to be sufficient to support the combined loads from the new structure and existing structure, no structural alterations are required.

  SECTION BO107—RELOCATED BUILDINGS

• CEBC § 501.3 High relevance — show source text

  Plans, investigation and evaluation reports, and other data shall be submitted indicating which building elements and materials the applicant is requesting the code official to review and approve for determination of applying the current building code fire-resistance ratings. Any special construction features, including fire-resistance-rated assemblies and smoke-resistive assemblies, conditions of occupancy, means of egress conditions, fire code deficiencies, approved modifications or approved alternative materials, design and methods of construction, and equipment applying to the building that impact required fire-resistance ratings shall be identified in the evaluation reports submitted.

  501.3 Health care facilities. In Group I-2 facilities, ambulatory care facilities and outpatient clinics, any altered or added portion of an existing electrical or medical gas systems shall be required to meet installation and equipment requirements in NFPA 99.

  501.4 Existing Group R occupancies. [SFM] See the California Residential Code for existing Group R-3 occupancies or Chapter 11 of the California Fire Code for all other existing Group R occupancies.

  501.5 Carbon monoxide alarms. [HCD 1, SFM] Pursuant to Health and Safety Code Section 17926, carbon monoxide detection shall be provided in all existing Group R buildings, as required in Section 915 of the California Building Code or Section R315 of the California Resi- dential Code, as applicable.

  501.5.1 Carbon monoxide detection in alterations to an existing Group E building. Where the alteration adds any of the condi- tions identified in the California Fire Code Sections 915.1.2 through 915.1.6 to an existing Group E building, not previously required to be provided with carbon monoxide detection, new carbon monoxide detection shall be installed in accordance with Section 915 of the California Fire Code.

  Exceptions: 1. The alteration replaces an existing fossil-fuel burning appliance, fireplace or forced-air furnace, or any of the conditions identified in Sections 915.1.2 through 915.1.6 are already present. 2. The Group E building was constructed before the adoption of the 2016 California Building Standards Code.

  SECTION 502—ADDITIONS

  502.1 General. Additions to any building or structure shall comply with the requirements of the California Building Code or California Residential Code, as applicable, for new construction. Alterations to the existing building or structure shall be made to ensure that

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  PRESCRIPTIVE COMPLIANCE METHOD

  the existing building or structure together with the addition are not less complying with the provisions of the California Building Code than the existing building or structure was prior to the addition except that the structural elements need only comply with Sections 502.2 through 502.3 . An existing building together with its additions shall comply with the height and area provisions of Chapter 5 of the California Building Code . Where a new occupiable roof is added to a building or structure, the occupiable roof shall comply with the provisions of the California Building Code. [OSHPD 1R, 2, 4 & 5] Structural elements shall comply with all the provisions of Section 502.

• California Existing Building Code High relevance — show source text

  |100 psf|1 hr
  23 min|||7|1, 2|11/3| |F/C-4-RC-9|4″|4″ deep (4370 psi);1/4″ reinforcement bars
  at 6″ pitch with3/4″ cover;1/4″ main rein-
  forcement bars at 4″ pitch perpendicular
  with1/2″ cover; 13′1″ span restrained.|150 psf|2 hrs|||7|1, 3|2| |F/C-4-RC-10|4″|4″ thick (5140 psi) deck;1/4″ reinforce-
  ment bars at 71/2″ pitch with7/8″ cover;3/8″
  main reinforcement bars at 33/4″ pitch
  perpendicular with1/2″ cover; 13′1″ span
  restrained.|140 psf|1 hr
  16 min|||7|1, 5|11/4| |F/C-4-RC-11|4″|4″ thick (4000 psi) concrete deck;
  3″ × 11/2″ × 4 lbs R.S.J.; 2′6″ C.R.S.; flush
  with top surface; 4″ × 6″ x 13 SWG mesh
  reinforcement 1″ from bottom of slab; 6′6″
  span restrained.|150 psf|2 hrs|||7|1, 3|2| |F/C-4-RC-12|4″|4″ deep (2380 psi) concrete deck;
  3″ × 11/2″ × 4 lbs R.S.J.; 2′6″ C.R.S.; flush
  with top surface; 4″ × 6″ x 13 SWG mesh
  reinforcement 1″ from bottom surface;
  6′6″ span restrained.|150 psf|1 hr
  3 min|||7|1, 2|1| |F/C-4-RC-13|41/2″|41/2″ thick (5200 psi) deck;1/4″ reinforce-
  ment bars at 71/4″ pitch with7/8″ cover;3/8″
  main reinforcement bars at 33/4″ pitch
  perpendicular with1/2″ cover; 13′1″ span
  restrained.|140 psf|2 hrs|||7|1, 3|2| |F/C-4-RC-14|41/2″|41/2″ deep (2525 psi) concrete deck;1/4″
  reinforcement bars at 71/2″ pitch with7/8″
  cover;3/8″ main reinforcement bars at
  33/8″ pitch perpendicular with1/2″ cover;
  13′1″ span restrained.|150 psf|42 min|||7|1, 5|2/3| |F/C-4-RC-15|41/2″|41/2″ deep (4830 psi) concrete deck;
  11/2″ × No.