CEBC · California Existing Building Code

How do plumbing, mechanical and other MEP systems change after an occupancy change?

If your building’s use changes, the CEBC requires upgrades when the new use creates grease/oil wastes (install a grease interceptor), chemical wastes (neutralize or replace piping and get sewer authority approval), or different light/ventilation needs (meet CBC). Exact fixture counts, interceptor sizing and ventilation rates come from the California Plumbing, Mechanical and Building Codes referenced in CEBC §§ 1009.3, 1009.4 and 1010.1.

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Last reviewed: July 6, 2026

What the code requires — 2-4 sentences

When the use of an existing building changes, the CEBC requires that MEP systems be reviewed and upgraded where the new occupancy introduces different or increased plumbing, mechanical, or lighting/ventilation needs. In plain English: if the new use will generate grease or oil‑laden wastes, you must provide an interceptor (see § 1009.3 ); if it will produce chemical wastes, you must neutralize them or replace incompatible piping and obtain sewage‑authority approval before discharge (see § 1009.4 ). Also, light and ventilation for the new occupancy must meet the California Building Code requirements for that occupancy (see § 1010.1 ).

The single most important rule: where the new occupancy changes the type or quantity of wastes, ventilation, or lighting, the building must be modified to meet the applicable plumbing, mechanical, or building‑code provisions — interceptors for grease, compatibility/neutralization for chemical wastes, and CBC light/ventilation standards for the new use (CEBC § 1009.3, § 1009.4, § 1010.1) .

Requirements in detail

Grease / oil‑laden wastes — interceptors

  • If the new occupancy will produce grease or oil‑laden wastes, the CEBC requires provision of an interceptor as required by the California Plumbing Code. The CEBC statement is brief — it mandates the interceptor requirement and defers sizing and location to the Plumbing Code (see § 1009.3 ).
  • Key practical point: plan for an interceptor when converting to restaurants, commercial kitchens, certain food‑service operations, or industrial processes that discharge fats/oils/grease.

Chemical wastes — piping compatibility, neutralization and approval

  • If the new occupancy will produce chemical wastes, CEBC § 1009.4 requires either:
    1. that existing piping be changed to a compatible material, or
    2. that wastes be neutralized prior to entry to the drainage system.
  • Additionally, chemical wastes shall not be discharged to a public sewer system without approval of the sewage authority (see § 1009.4 ).
  • Practical implication: laboratory, auto‑shop, photo‑processing, chemical storage, and similar uses require early coordination with the plumbing designer and local sewer authority.

Light and ventilation

  • The CEBC requires that light and ventilation for the new occupancy comply with the California Building Code requirements for that occupancy (see § 1010.1 ).
  • For mechanical ventilation or kitchen exhaust changes specifically, CEBC also directs compliance with the California Mechanical Code when the new occupancy triggers different ventilation or exhaust requirements (see § 1008.1 ).

Increased plumbing demand (related)

  • Where occupant load changes trigger increased fixture requirements, CEBC directs compliance with the California Plumbing Code; the CEBC also contains an explicit exception: plumbing fixtures need be updated based on code quantities only where the occupant load of the story increases by more than 20% (see § 1009.1 ).
  • Note: the CEBC phrases these as directions to comply with the referenced California Plumbing/Mechanical/Building Codes — the detailed fixture counts, interceptor sizing, and ventilation rates appear in those codes, not in the CEBC text itself.

Decision table — when an MEP change is required

Decision dimension Trigger / value Required action under CEBC Code Reference
Waste type = grease / oil‑laden New occupancy WILL produce grease/oil wastes Provide an interceptor sized/installed per California Plumbing Code § 1009.3
Waste type = chemical New occupancy WILL produce chemical wastes Neutralize wastes or replace piping with compatible material; obtain sewage authority approval before discharge to public sewer § 1009.4
Occupant load change (plumbing fixtures) Story occupant load increases > 20% Provide plumbing fixtures in quantities specified by California Plumbing Code based on increased load § 1009.1
Ventilation / kitchen exhaust New occupancy subject to different kitchen exhaust or increased mechanical ventilation Comply with California Mechanical Code provisions for the new occupancy § 1008.1
Light & ventilation standards Any change of occupancy Light and ventilation must meet California Building Code requirements for the new occupancy § 1010.1

Exceptions & special cases

  • The CEBC itself mostly states the obligation and defers technical specifics to the referenced codes. For example, § 1009.3 and § 1009.4 require interceptors and chemical‑waste controls but rely on the California Plumbing Code for sizing and installation details .
  • The CEBC provides an explicit exception on plumbing fixtures: only where a story’s occupant load increases by more than 20% must fixtures be recalculated and provided per the Plumbing Code (§ 1009.1 exception) .
  • For ventilation: if the change creates new kitchen exhaust or different mechanical ventilation requirements, the California Mechanical Code controls the technical solution (§ 1008.1) .
  • Where the CEBC refers to other codes (California Plumbing, Mechanical, Building Codes), those referenced codes — not the CEBC — contain the technical tables, calculations, and equipment sizing you must follow.

Common mistakes

  • Assuming the CEBC itself contains detailed sizing or fixture tables — it does not; it defers to the California Plumbing and Mechanical Codes (see § 1009.3, § 1009.4, § 1010.1) .
  • Failing to plan for a grease interceptor when converting to a food service use — inspectors will require one per § 1009.3 and the Plumbing Code.
  • Not coordinating with the local sewage authority before discharging chemical wastes; § 1009.4 requires approval before discharge to a public sewer system .
  • Overlooking the > 20% occupant‑load threshold: owners sometimes retrofit fewer fixtures than required because they miss that the CEBC exception is only for increases of 20% or less — more than 20% triggers new counts per the Plumbing Code (§ 1009.1) .
  • Forgetting that light and ventilation requirements change with occupancy and are enforced to the California Building Code standard (see § 1010.1) .

Worked example — converting a warehouse to a food service + small lab

Scenario: You convert a single floor warehouse (existing occupant load = 50) to a space that will include a restaurant kitchen and a small chemical testing lab. The new occupant load for the floor is calculated at 82.

  1. Occupant‑load change percentage: (82 − 50) / 50 = 0.64 = 64% increase → this is > 20%, so plumbing fixtures for the story must be provided in quantities specified by the California Plumbing Code based on the new occupant load (CEBC § 1009.1 ) .

    • Action: engage a plumbing designer to compute required water closet/urinal/lavatory counts from the California Plumbing Code tables and provide those fixtures.

  2. Restaurant kitchen will generate grease/oil‑laden wastes → CEBC § 1009.3 requires a grease interceptor sized and installed per the California Plumbing Code .

    • Action: specify and install a grease interceptor; sizing and trap location per Plumbing Code (not reproduced in CEBC).

  3. Chemical testing lab will produce chemical wastes → CEBC § 1009.4 requires either: replace piping with a compatible material OR neutralize the waste before entering the drainage system; and get sewage authority approval before any discharge to the public sewer .

    • Action: determine chemical compatibility, provide neutralization or specialty waste piping, and secure written approval (or permit conditions) from the sewer authority.

  4. Ventilation and kitchen exhaust: CEBC points to the California Mechanical Code where new kitchen exhaust or different ventilation rates are required (CEBC § 1008.1) .

    • Action: HVAC designer to provide make‑up air, hood exhaust, and system modifications to meet Mechanical Code.

Note: the CEBC tells you what to do (install interceptor, neutralize chemical waste, meet CBC light/ventilation), but the exact fixture counts, interceptor sizing, and ventilation rates come from the California Plumbing, Mechanical, and Building Codes referenced in the CEBC. The specific tables and formulas are not reproduced in the CEBC excerpts used here; consult those codes and local sewer authority for the technical specs.

Related provisions (CEBC)

  • § 1009.1 — Increased demand; occupant‑load threshold for plumbing fixture requirements (see CEBC § 1009.1) .
  • § 1008.1 — Mechanical requirements; kitchen exhaust and mechanical ventilation changes are controlled by the California Mechanical Code (see CEBC § 1008.1) .
  • § 1009.2 — Food‑handling occupancies; sanitary waste lines above food prep areas must be panned or otherwise protected (see CEBC § 1009.2) .
  • § 1010.1 — Light and ventilation must comply with the California Building Code for the new occupancy (see CEBC § 1010.1) .
  • § 1011.1 – 1011.2 — Change of occupancy classification; fire protection systems and alarms may also be required when occupancy classification changes (see CEBC § 1011.1 and § 1011.2) .
  • For technical details (fixture counts, interceptor sizing, ventilation rates): see the referenced California Plumbing Code, California Mechanical Code, and California Building Code as directed by the CEBC (§§ 1009.3, 1009.4, 1010.1) .

Code references

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

  • CEBC § 1008.1 High relevance — show source text

    SECTION 1008—MECHANICAL

    1008.1 Mechanical requirements. Where the occupancy of an existing building or part of an existing building is changed such that the new occupancy is subject to different kitchen exhaust requirements or to increased mechanical ventilation requirements in accordance with the California Mechanical Code, the new occupancy shall comply with the respective California Mechanical Code provisions.

    SECTION 1009—PLUMBING

    1009.1 Increased demand. Where the occupancy of an existing building or part of an existing building is changed such that the new occupancy is subject to increased or different plumbing fixture requirements or to increased water supply requirements in accor

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    dance with the California Plumbing Code, the new occupancy shall comply with the intent of the respective California Plumbing Code provisions.

    Exception: Only where the occupant load of the story is increased by more than 20 percent, plumbing fixtures for the story shall be provided in quantities specified in the California Plumbing Code based on the increased occupant load.

    1009.2 Food-handling occupancies. If the new occupancy is a food-handling establishment, all existing sanitary waste lines above the food or drink preparation or storage areas shall be panned or otherwise protected to prevent leaking pipes or condensation on pipes from contaminating food or drink. New drainage lines shall not be installed above such areas and shall be protected in accordance with the California Plumbing Code .

    1009.3 Interceptor required. If the new occupancy will produce grease or oil-laden wastes, interceptors shall be provided as required in the California Plumbing Code .

    1009.4 Chemical wastes. If the new occupancy will produce chemical wastes, the following shall apply:

    1. If the existing piping is not compatible with the chemical waste, the waste shall be neutralized prior to entering the drainage system or the piping shall be changed to a compatible material.
    2. Chemical waste shall not discharge to a public sewer system without the approval of the sewage authority.

    SECTION 1010—OTHER REQUIREMENTS

    1010.1 Light and ventilation. Light and ventilation shall comply with the requirements of the California Building Code for the new

    occupancy.

    SECTION 1011—CHANGE OF OCCUPANCY CLASSIFICATION

    1011.1 General. The provisions of this section shall apply to buildings or portions thereof undergoing a change of occupancy classification. This includes a change of occupancy classification within a group as well as a change of occupancy classification from one group to a different group. The provisions of this section shall also apply where there is a change of occupancy within a building or portion thereof and there is a different fire protection system threshold requirement in Chapter 9 of the current California Building Code than exists in the current building or space. Such buildings shall also comply with Sections 1002 through 1010 of this code.

    1011.2 Fire protection systems. Fire protection systems shall be provided in accordance with Sections 1011.2.1 and 1011.2.2.

  • CEBC § 1007.1 High relevance — show source text

    SECTION 1007—ELECTRICAL

    1007.1 Special occupancies. Where the occupancy of an existing building or part of an existing building is changed to one of the following special occupancies as described in the California Electrical Code, the electrical wiring and equipment of the building or portion thereof that contains the proposed occupancy shall comply with the applicable requirements of the California Electrical Code :

    1. Hazardous locations.

    2. Commercial garages, repair and storage.

    3. Aircraft hangars.

    4. Gasoline dispensing and service stations.

    5. Bulk storage plants.

    6. Spray application, dipping and coating processes.

    7. Reserved.

    8. Places of assembly.

    9. Theaters, audience areas of motion picture and television studios, and similar locations.

    10. Motion picture and television studios and similar locations.

    11. Motion picture projectors.

    12. Agricultural buildings.

    1007.2 Unsafe conditions. Where the occupancy of an existing building or part of an existing building is changed, all unsafe conditions shall be corrected without requiring that all parts of the electrical system comply with the California Electrical Code .

    1007.3 Service upgrade. Where the occupancy of an existing building or part of an existing building is changed, electrical service shall be upgraded to meet the requirements of the California Electrical Code for the new occupancy.

    1007.4 Number of electrical outlets. Where the occupancy of an existing building or part of an existing building is changed, the number of electrical outlets shall comply with the California Electrical Code for the new occupancy.

    SECTION 1008—MECHANICAL

    1008.1 Mechanical requirements. Where the occupancy of an existing building or part of an existing building is changed such that the new occupancy is subject to different kitchen exhaust requirements or to increased mechanical ventilation requirements in accordance with the California Mechanical Code, the new occupancy shall comply with the respective California Mechanical Code provisions.

    SECTION 1009—PLUMBING

    1009.1 Increased demand. Where the occupancy of an existing building or part of an existing building is changed such that the new occupancy is subject to increased or different plumbing fixture requirements or to increased water supply requirements in accor

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    dance with the California Plumbing Code, the new occupancy shall comply with the intent of the respective California Plumbing Code provisions.

    Exception: Only where the occupant load of the story is increased by more than 20 percent, plumbing fixtures for the story shall be provided in quantities specified in the California Plumbing Code based on the increased occupant load.

    1009.2 Food-handling occupancies. If the new occupancy is a food-handling establishment, all existing sanitary waste lines above the food or drink preparation or storage areas shall be panned or otherwise protected to prevent leaking pipes or condensation on pipes from contaminating food or drink. New drainage lines shall not be installed above such areas and shall be protected in accordance with the California Plumbing Code .

    1009.3 Interceptor required. If the new occupancy will produce grease or oil-laden wastes, interceptors shall be provided as required in the California Plumbing Code .

  • CEBC § 1009.3 High relevance — show source text

    1009.3 Interceptor required. If the new occupancy will produce grease or oil-laden wastes, interceptors shall be provided as required in the California Plumbing Code .

    1009.4 Chemical wastes. If the new occupancy will produce chemical wastes, the following shall apply:

    1. If the existing piping is not compatible with the chemical waste, the waste shall be neutralized prior to entering the drainage system or the piping shall be changed to a compatible material.
    2. Chemical waste shall not discharge to a public sewer system without the approval of the sewage authority.

    SECTION 1010—OTHER REQUIREMENTS

    1010.1 Light and ventilation. Light and ventilation shall comply with the requirements of the California Building Code for the new

    occupancy.

    SECTION 1011—CHANGE OF OCCUPANCY CLASSIFICATION

    1011.1 General. The provisions of this section shall apply to buildings or portions thereof undergoing a change of occupancy classification. This includes a change of occupancy classification within a group as well as a change of occupancy classification from one group to a different group. The provisions of this section shall also apply where there is a change of occupancy within a building or portion thereof and there is a different fire protection system threshold requirement in Chapter 9 of the current California Building Code than exists in the current building or space. Such buildings shall also comply with Sections 1002 through 1010 of this code.

    1011.2 Fire protection systems. Fire protection systems shall be provided in accordance with Sections 1011.2.1 and 1011.2.2.

    1011.2.1 Automatic sprinkler system. The installation of an automatic sprinkler system shall be required where there is a change of occupancy classification and Chapter 9 of the current California Building Code requires an automatic sprinkler system based on the new occupancy or where there is a change of occupancy within the space where there is a different fire protection system threshold requirement in Chapter 9 of the current California Building Code than exists in the current building or space . The installation of the automatic sprinkler system shall be required within the area of the change of occupancy and areas of the building not separated by a fire wall from the change of occupancy.

    1011.2.1.1 Nonrequired automatic sprinkler systems. The code official is authorized to permit the removal of an existing automatic sprinkler system where all of the following conditions exist:

    1. The system is not required for new construction.
    2. Portions of the system that are exposed to the public are removed.
    3. The system was not installed as part of 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.

    1011.2.1.1.1 Approval. Plans, investigation and evaluation reports, and other data shall be submitted documenting compliance with Section 1011.2.1.1 for review and approval in support of a determination authorizing the removal of the automatic sprinkler system by the code official.

    1011.2.2 Fire alarm and detection system. Where a change in occupancy classification occurs or where there is a change of occupancy within a space where there is a different fire protection system threshold requirement in Chapter 9 of the current Cali- fornia Building Code than exists in the current building or space that requires a fire alarm and detection system to be provided based on the new occupancy, such system shall be in accordance with Chapter 11 and Section 907 of the California Fire Code.

  • CEBC § 101.4 Medium relevance — show source text

    [A] 101.4 Referenced codes. The other codes specified in Sections 101.4.1 through 101.4.7 and referenced elsewhere in this code shall be considered to be part of the requirements of this code to the prescribed extent of each such reference.

    [A] 101.4.1 Gas. The provisions of the California Plumbing Code and/or the California Mechanical Code shall apply to the installation of gas piping from the point of delivery, gas appliances and related accessories as covered in this code. These requirements apply to gas piping systems extending from the point of delivery to the inlet connections of appliances and the installation and operation of residential and commercial gas appliances and related accessories.

    [A] 101.4.2 Mechanical. The provisions of the California Mechanical Code shall apply to the installation, alterations, repairs and replacement of mechanical systems, including equipment, appliances, fixtures, fittings and appurtenances, including ventilating, heating, cooling, air-conditioning and refrigeration systems, incinerators and other energy-related systems.

    [A] 101.4.3 Plumbing. The provisions of the California Plumbing Code shall apply to the installation, alteration, repair and replacement of plumbing systems, including equipment, appliances, fixtures, fittings and appurtenances, and where connected to a water or sewage system and all aspects of a medical gas system. The provisions of the California Plumbing Code shall apply to private sewage disposal systems.

    [A] 101.4.4 Property maintenance. The provisions of the California Existing Building Code shall apply to existing structures and premises; equipment and facilities; light, ventilation, space heating, sanitation, life and fire safety hazards; responsibilities of owners, operators and occupants; and occupancy of existing premises and structures.

    [A] 101.4.5 Fire prevention. The provisions of the California Fire Code shall apply to matters affecting or relating to structures, processes and premises from the hazard of fire and explosion arising from the storage, handling or use of structures, materials or devices; from conditions hazardous to life, property or public welfare in the occupancy of structures or premises; and from the construction, extension, repair, alteration or removal of fire suppression, automatic sprinkler systems and alarm systems or fire hazards in the structure or on the premises from occupancy or operation.

    [A] 101.4.6 Energy. The provisions of the California Energy Code shall apply to all matters governing the design and construction of buildings for energy efficiency.

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    [A] 101.4.7 Existing buildings. The provisions of the California Existing Building Code shall apply to matters governing the repair, alteration, change of occupancy, addition to and relocation of existing buildings.

    [OSHPD 1] The provisions of Chapters 2, 3A, 4A and 5A of the California Existing Building Code shall apply to all matters governing the repairs, alterations, change of occupancy, additions and relocation of existing structures and portions thereof under OSHPD jurisdic- tion. All references to Chapters 3, 4 and 5 of the California Existing Building Code shall be replaced by equivalent provisions in Chapters 3A, 4A and 5A.

  • CEBC § 1006.3 Medium relevance — show source text

    Exception: Where the area of the new occupancy is less than 10 percent of the building area. The cumulative effect of occupancy changes over time shall be considered.

    [BS] 1006.3 Seismic loads. Where a change of occupancy results in a building being assigned to a higher risk category, or where the change is from a Group S or Group U occupancy to any occupancy other than Group S or Group U, the lateral force-resisting system of the building shall comply with Section 304.3.1 for the new risk category. Where a change of occupancy results in a building being assigned to Risk Category IV and Seismic Design Category D or F, nonstructural components serving any portion of the building changed to Risk Category IV shall comply with the requirements of Section 1613 of the California Building Code or shall comply with ASCE 41 using an objective of operational nonstructural performance with the BSE-1N earthquake hazard level.

    Exceptions:

    1. Where a change of use results in a building being reclassified from Risk Category I or II to Risk Category III and the seismic coefficient, S DS, is less than 0.33, compliance with this section is not required.

    2. Where the area of the new occupancy is less than 10 percent of the building area, the occupancy is not changing from a Group S or Group U occupancy, and the new occupancy is not assigned to Risk Category IV, compliance with this section is not required. The cumulative effect of occupancy changes over time shall be considered.

    3. Reserved.

    4. Where the change is from a Group S or Group U occupancy and there is no change of risk category, compliance with Section 304.3.2 shall be permitted.

    [BS] 1006.4 Access to Risk Category IV. Any structure that provides operational access to an adjacent structure assigned to Risk Category IV as the result of a change of occupancy shall itself comply with Sections 1608 and 1609 of the California Building Code and Section 304.3.1 of this code. Where operational access to Risk Category IV is less than 10 feet (3048 mm) from either an interior lot line or from another structure, access protection from potential falling debris shall be provided.

    SECTION 1007—ELECTRICAL

    1007.1 Special occupancies. Where the occupancy of an existing building or part of an existing building is changed to one of the following special occupancies as described in the California Electrical Code, the electrical wiring and equipment of the building or portion thereof that contains the proposed occupancy shall comply with the applicable requirements of the California Electrical Code :

    1. Hazardous locations.

    2. Commercial garages, repair and storage.

    3. Aircraft hangars.

    4. Gasoline dispensing and service stations.

    5. Bulk storage plants.

    6. Spray application, dipping and coating processes.

    7. Reserved.

    8. Places of assembly.

    9. Theaters, audience areas of motion picture and television studios, and similar locations.

    10. Motion picture and television studios and similar locations.

    11. Motion picture projectors.

    12. Agricultural buildings.

    1007.2 Unsafe conditions. Where the occupancy of an existing building or part of an existing building is changed, all unsafe conditions shall be corrected without requiring that all parts of the electrical system comply with the California Electrical Code .

    1007.3 Service upgrade. Where the occupancy of an existing building or part of an existing building is changed, electrical service shall be upgraded to meet the requirements of the California Electrical Code for the new occupancy.

  • CEBC § 1.10.1 Medium relevance — show source text

    **_ 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). Functional service spaces shall comply with the requirements in the California Building Code, Sections 1224, 1225, 1226, 1227 and 1228.

    301.1.1 Bleachers, folding and telescopic seating and grandstands. Existing bleachers, folding and telescopic seating and grandstands shall comply with ICC 300.

    301.2 Repairs. Repairs shall comply with the requirements of Chapter 4.

    301.3 Alteration, addition or change of occupancy. The alteration, addition or change of occupancy of all existing buildings shall comply with one of the methods listed in Section 301.3.1, 301.3.2 or 301.3.3 as selected by the applicant. Sections 301.3.1 through 301.3.3 shall not be applied in combination with each other. [OSHPD 1R, 2, 4 and 5] Sections 301.3.2 and 301.3.3, not adopted by OSHPD.

    Exception: Subject to the approval of the code official, alterations complying with the laws in existence at the time the building or the affected portion of the building was built shall be considered in compliance with the provisions of this code. New structural

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    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.

  • CEBC § 501A.3.3.3 Medium relevance — show source text

    501A.3.3.3 For NPC 3 and NPC 4 or NPC 4D in SPC 2, SPC 3, SPC 4 or SPC-4D buildings, the adequacy and design of nonstructural component or equipment supports and attachments may extend only to the connection of the component or equipment to the support when the total reaction at the point of support (including the application of F p ) is less than or equal to the following limits: 1. 250 pounds for components or equipment attached to light frame walls. For the purposes of this requirement, the sum of the absolute value of all reactions due to component loads on a single stud shall not exceed 250 pounds. 2. 1,000 pounds for components or equipment attached to roofs or walls of reinforced concrete or masonry construction. 3. 2,000 pounds for components or equipment attached to floors or slabs-on-grade.

    Exception: If the anchorage or bracing is configured in a manner that results in significant torsion on a supporting structural element, the effects of the nonstructural reaction force on the structural element shall be considered in the anchorage design.

    501 A . 4 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.

    SECTION 502 A —ADDITIONS

    502 A .1 General. Additions to any building or structure shall comply with the requirements of the California Building Code for new construction. Alterations to the existing building or structure shall be made to ensure that 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. 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.

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

    502 A .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 A .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 A 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 A .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.

  • CEBC § 1001.2.1 Medium relevance — show source text

    1001.2.1 Change of use. Any work undertaken in connection with a change in use shall conform to the applicable requirements for the work as classified in Chapter 6 and to the requirements of Sections 1002 through 1010.

    1001.2.2 Change of occupancy classification. Where a building undergoes a change of occupancy classification, the provisions of Sections 1002 through 1011 shall apply.

    1001.2.2.1 Partial change of occupancy. Where a portion of an existing building undergoes a change of occupancy classification, Section 1011 shall apply.

    1001.3 Certificate of occupancy required. A certificate of occupancy shall be issued where a change of occupancy occurs that results in a different occupancy classification as determined by the California Building Code .

    SECTION 1002—SPECIAL USE AND OCCUPANCY

    1002.1 Compliance with the building code. Where an existing building or part of an existing building undergoes a change of occupancy to one of the special use or occupancy categories as described in Chapter 4 in the California Building Code, the building shall comply with all of the requirements of Chapter 4 of the California Building Code applicable to the special use or occupancy.

    1002.2 Incidental uses. Where a portion of a building undergoes a change of occupancy to one of the incidental uses listed in Table 509.1 of the California Building Code, the incidental use shall comply with Section 509 of the California Building Code applicable to the incidental use.

    SECTION 1003—BUILDING ELEMENTS AND MATERIALS

    1003.1 General. Building elements and materials in portions of buildings undergoing a change of occupancy classification shall comply with Section 1011.

    SECTION 1004—FIRE PROTECTION

    1004.1 General. Fire protection requirements in Section 1011 shall apply where either of the following occur:

    1. A building or portion thereof undergoes a change of occupancy.
    2. A building or portion thereof undergoes a change of occupancy and there is a different fire protection system threshold requirement in Chapter 9 of the current California Building Code than exists in the current building or portion thereof.

    SECTION 1005—MEANS OF EGRESS

    1005.1 General. Means of egress in portions of buildings undergoing a change of occupancy classification shall comply with Section 1011.

    SECTION 1006—STRUCTURAL

    [BS] 1006.1 Live loads. Structural elements carrying tributary live loads from an area with a change of occupancy shall satisfy the requirements of Section 1607 of the California Building Code . Design live loads for areas of new occupancy shall be based on Section 1607 of the California Building Code . Design live loads for other areas shall be permitted to use previously approved design live loads.

    Exception: Structural elements whose demand-capacity ratio considering the change of occupancy is not more than 5 percent greater than the demand-capacity ratio based on previously approved live loads.

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    CHANGE OF OCCUPANCY

    [BS] 1006.2 Snow and wind loads. Where a change of occupancy results in a structure being assigned to a higher risk category, the structure shall satisfy the requirements of Sections 1608 and 1609 of the California Building Code for the new risk category.

  • CEBC § 1.10.1 Medium relevance — show source text

    Chapter 5A Prescriptive Compliance Method.

    Chapter 5A provides details for the prescriptive compliance method for alteration, addition and change of occupancy of existing build- ings and structures regulated by the Department of Health Care Access and Information/Office of Statewide Hospital Planning and Development, which include hospitals and correctional treatment centers (applications listed in Sections 1.10.1 (OSHPD 1).

    Chapter 6 Classification of Work.

    Chapter 6 provides an overview of the Work Area Method and defines the different classifications of work including alterations, change of occupancy, additions and historic buildings. Detailed requirements for all of these are given in subsequent Chapters 7 through 11.

    Chapter 7 Alterations—Level 1.

    Chapter 7 provides the technical requirements for those existing buildings that undergo Level 1 alterations as described in Section 602, which includes replacement or covering of existing materials, elements, equipment or fixtures using new materials for the same purpose. This chapter is distinguished from Chapters 8 and 9 by only involving replacement of building components with new components with no reconfiguration of space.

    Chapter 8 Alterations—Level 2.

    A Level 2 alteration is an alteration involving space reconfiguration that could be up to and including 50 percent of the area of the building or addition of a new building system. Level 2 alterations also include the extension or addition of any system or equipment. The purpose of Chapter 8 is to provide detailed requirements and provisions to identify the required improvements in the existing building elements, means of egress, fire protection, structural systems, energy efficiency, and other building systems include electrical, mechanical and plumbing when a building is being altered.

    Chapter 9 Alterations—Level 3.

    Chapter 9 provides the technical requirements for those existing buildings that undergo Level 3 alterations. Level 3 alterations are those involving alterations that cover 50 percent of the aggregate area of the building. Under certain situations, this chapter also intends to improve the safety of certain building features beyond the work area and in other parts of the building where no alteration work might be taking place.

    Chapter 10 Change of Occupancy.

    The purpose of Chapter 10 is to address existing buildings that are subject to a change of occupancy. This chapter is an assembly of requirements to upgrade safety without having to comply fully as a new building. A change of occupancy classification is considered a change of occupancy, however, it will involve a higher level of regulation since the use of the building has made a more significant change.

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    Chapter 11 Additions.

    Chapter 11 provides the requirements for additions, which are considered new construction. The requirements focus on safely integrating the addition with the existing building. This includes issues such as limiting the overall height and area of the building where the addition is not separated by a fire wall.

    Chapter 12 Historic Buildings —Reserved

    Chapter 12 is not adopted by the State of California. Historic buildings and structures shall comply with Part 8, Title 24, California Code of Regulations.

    Chapter 13 Performance Compliance Methods.

    Chapter 13 allows for existing buildings to be evaluated to show that alterations or a change of occupancy, while not meeting new construction requirements, will provide a level of safety to demonstrate compliance. Provisions are based on a numerical scoring system involving 21 safety parameters where, when evaluated, such buildings must meet a minimum overall safety score.

  • CEBC § 101.1 Medium relevance — show source text

    This code is intended to be adopted as a legally enforceable document, and it cannot be effective without adequate provisions for its administration and enforcement. The provisions of Chapter 1 establish the authority and duties of the code official appointed by the authority having jurisdiction and also establish the rights and privileges of the registered design professional, contractor and property owner.

    Section 104 was revised for the 2024 edition of the IEBC. For complete information, see the Relocations table in the Preface of this code.

    PART 1—SCOPE AND APPLICATION

    SECTION 101—SCOPE AND GENERAL REQUIREMENTS

    [A] 101.1 Title. These regulations shall be known as the Existing Building Code of [ NAME OF JURISDICTION ], herein-after referred to as “this code.”

    [A] 101.2 Scope. The provisions of this code shall apply to the repair, alteration, change of occupancy, addition to and relocation of existing buildings.

    Exception: Detached one- and two-family dwellings and townhouses not more than three stories above grade plane in height with a separate means of egress, and their accessory structures not more than three stories above grade plane in height, shall comply with this code or the California Residential Code.

    [A] 101.2.1 Appendices. Provisions in the appendices shall not apply unless specifically adopted or referenced.

    101.2.2 Application of fire code. Where work regulated by this code is also regulated by the construction requirements for existing buildings in Chapter 11 of the California Fire Code, such work shall comply with applicable requirements in both codes.

    [A] 101.3 Purpose. The intent of this code is to provide flexibility to permit the use of alternative approaches to achieve compliance with minimum requirements to provide a reasonable level of safety, health, property protection and general welfare insofar as they are affected by the repair, alteration, change of occupancy, addition and relocation of existing buildings.

    [A] 101.4 Applicability. This code shall apply to the repair, alteration, change of occupancy, addition and relocation of existing buildings, regardless of occupancy, subject to the criteria of Sections 101.4.1 and 101.4.2.

    [A] 101.4.1 Buildings not previously occupied. A building or portion of a building that has not been previously occupied or used for its intended purpose, in accordance with the laws in existence at the time of its completion, shall be permitted to comply with the provisions of the laws in existence at the time of its original permit unless such permit has expired. Subsequent permits shall comply with the California Building Code or California Residential Code, as applicable, for new construction.

    [A] 101.4.2 Buildings previously occupied. The legal occupancy of any building existing on the date of adoption of this code shall be permitted to continue without change, except as is specifically covered in this code, the California Fire Code, or the Inter- national Property Maintenance Code, or as is deemed necessary by the code official for the general safety and welfare of the occupants and the public.

    [A] 101.5 Safeguards during construction. Construction work covered in this code, including any related demolition, shall comply with the requirements of Chapter 15.

  • CEBC § 10-3 Medium relevance — show source text

    1003 Building Elements and Materials . . . . . . . . . . . . . . . . 10-3

    1004 Fire Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-3

    1005 Means of Egress . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-3

    1006 Structural. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-3

    1007 Electrical . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-4

    1008 Mechanical. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-4

    1009 Plumbing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-4

    1010 Other Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-5

    1011 Change of Occupancy Classification . . . . . . . . . . . . . 10-5

    CHAPTER 11 ADDITIONS . . . . . . . . . . . . . . . . . . . . . . . . . . .11-3

    1101 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-3

    1102 Heights and Areas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-3

    1103 Structural. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-4

    1104 Energy Conservation. . . . . . . . . . . . . . . . . . . . . . . . . . . 11-4

    CHAPTER 12 HISTORIC BUILDINGS . . . . . . . . . . . . . . . . . .12-1

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    CHAPTER 13 PERFORMANCE COMPLIANCE METHODS. . 13-3

    1301 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-3

    1302 Applicability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-3

    1303 Acceptance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-4

  • CEBC § 1.11.5.1 Medium relevance — show source text

    1.11.5.1 Existing Group I-1 or R Occupancies. Licensed 24-hour care in a Group I-1 or R occupancy in existence and originally classified under previously adopted state codes shall be reinspected under the appropriate previ- ous code, provided there is no change in the use or char- acter which would place the facility in a different

    occupancy group.

    1.11.6 Certificate of Occupancy. A Certificate of Occupancy shall be issued as specified in Title 24, Part 2, California Building Code, Section 111.

    Exception: Certificates of occupancy are not required for work exempt from permits in accordance with Section 105.2 of the California Building Code.

    1.11.7 Temporary Structures and Uses. See Title 24, Part 2, California Building Code, Section 108.

    1.11.8 Service Utilities. See Title 24, Part 2, California Build- ing Code, Section 112.

    1.11.9 Stop Work Order. See Title 24, Part 2, California Building Code, Section 115.

    1.11.10 Unsafe Buildings, Structures, and Equipment. See Title 24, Part 2, California Building Code, Section 116.

    1.11.11 Adopting Agency Identification. The provisions of this code applicable to buildings identified in this section will be identified in the Matrix Adoption Tables under the acronym SFM.

    1.12.0 Reserved for the State Librarian.

    1.13.0 Department of Water Resources (DWR).

    1.13.1 Application – Design standards to safely plumb build- ings with both potable and recycled water systems.

    Enforcing Agency – State or local agency specified by the applicable provisions of law.

    Authority Cited – Water Code Section 13557.

    References – Water Code Section 13553.

    1.13.2 Adopting Agency Identification. The provisions of this code applicable to buildings identified in this section will be identified in the Matrix Adoption Tables under the acronym DWR.

    1.14.0 Reserved for the State Lands Commission.

    2025 CALIFORNIA PLUMBING CODE 19

    ), Copyright © 2025 IAPMO, and may not be used for any other purpose or distributed to any other persons or parties.

    20 2025 CALIFORNIA PLUMBING CODE

    ), Copyright © 2025 IAPMO, and may not be used for any other purpose or distributed to any other persons or parties.

    DIVISION II

    SCOPE AND ADMINISTRATION

    101.0 General.

    101.1 Title. This document shall be known as the “Uniform Plumbing Code,’’ may be cited as such, and will be referred to herein as “this code.”

    101.2 Scope. The provisions of this code shall apply to the erection, installation, alteration, repair, relocation, replacement, addition to, use, or maintenance of plumbing systems within this jurisdiction.

    101.3 Purpose. This code is an ordinance providing minimum requirements and standards for the protection of the public health, safety, and welfare.

Frequently asked questions

Do I always need a grease interceptor when I change to a food service use?

If the new occupancy will produce grease or oil‑laden wastes, yes — the CEBC requires an interceptor and defers sizing/installation to the California Plumbing Code (see § 1009.3) .

What if my new use generates small amounts of chemicals — do I still need sewer authority approval?

Yes. § 1009.4 requires either compatible piping or neutralization and mandates that chemical waste shall not discharge to a public sewer without the sewage authority’s approval .

When do plumbing fixture counts have to change?

Plumbing fixtures must be provided in the quantities in the California Plumbing Code when a story’s occupant load increases by more than 20%; under that threshold the CEBC does not automatically require fixtures based solely on occupant‑load change (see § 1009.1) .

Are ventilation and exhaust changes governed by the CEBC?

The CEBC requires compliance when ventilation or kitchen exhaust requirements change, but the technical standards are in the California Mechanical Code (see § 1008.1 and § 1010.1) .

Who enforces the chemical‑waste sewer approval?

The local sewage authority (municipal sewer agency) has jurisdiction; plan review and permitting for chemical waste discharge are handled by that authority per CEBC § 1009.4 .

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California Existing Building Code