CMC · California Mechanical Code
When is a permit required and what work is exempt?
In short: the California Mechanical Code requires a permit for any installation, alteration, repair, replacement, or remodel of a mechanical system unless the work is specifically listed as exempt. The CMC lists the permit requirement at **§ 104.1** and the exemptions at **§ 104.2**; related California codes (CBC/Existing) restate similar rules at **§ 105.1** / **§ 105.2** and may add numeric thresholds (for example, **10 lb** refrigerant for some self-contained units). Always confirm with your local Authority Having Jurisdiction because exemptions don’t override other laws and the AHJ may require a permit where safety is a concern.
Last reviewed: July 6, 2026
What the code requires — 2-4 sentences
The California Mechanical Code requires a separate mechanical permit before you install, alter, repair, replace or remodel a mechanical system — this is the permit rule in the CMC at § 104.1. Work specifically listed as exempt does not require a permit; those exemptions are in § 104.2. Note: other California codes (e.g., the California Building Code / Existing Building Code) list parallel permit/ exemption language at § 105.1 and § 105.2, which jurisdictions may also reference when enforcing permits locally.
The single most important rule: obtain a mechanical permit for any regulated installation, alteration, replacement or remodeling of a mechanical system unless the work is specifically listed as exempt in the code (see § 104.1 and § 104.2).
Requirements in detail
When a permit is required (plain decision rule)
A permit is required for any installation, alteration, repair, replacement or remodel of a mechanical system regulated by the CMC — § 104.1. The permit is generally required per separate building/structure and is obtained from the Authority Having Jurisdiction (AHJ).
The application must identify the work, location, use/occupancy, include construction documents when required, and be signed by the permittee or authorized agent — see § 104.3.
If work begins without a permit, the AHJ may require a special investigation and assess an investigation fee in addition to the permit fee — see § 104.5.1 and § 104.5.2.
What work is exempt (decision table)
The table below lists the common CMC exemptions that most often determine whether a permit is required. Use the Code Reference column to find the governing text.
| Exempt work (decision-relevant) | Key decision detail (what to check) | Code Reference |
|---|---|---|
| Portable heating, ventilating or cooling appliances | Standalone portable units (not permanently installed) | § 104.2(1) |
| Portable evaporative cooler | Portable, not permanently piped or mounted | § 104.2(1) |
| Closed steam, hot or chilled water piping within regulated equipment | Piping entirely inside heating/cooling equipment (not building piping) | § 104.2(2) |
| Replacement of a component part that does not alter original approval | Part-for-part replacement that does not change listed rating or make equipment unsafe | § 104.2(3) |
| Refrigerating equipment that is part of equipment already permitted | Refrigeration that is integral to equipment for which a permit exists | § 104.2(4) |
| Unit / self-contained refrigerating systems | Many jurisdictions treat small, self-contained units as exempt; see limits below | § 104.2(5); Existing Building Code clarifies small systems (≤ 10 lb refrigerant, ≤ 1 hp) as exempt. |
| Minor repairs/maintenance (related codes) | Ordinary maintenance or minor repairs that do not alter approval/safety or change systems | See exception language in related code sections (R/CBC/Existing) and AHJ discretion; e.g., Existing Building Code lists similar mechanical exemptions. § 105.2 (CBC/Existing) |
Notes on the table:
- The CMC’s exemption list is concise; some California codes (Existing Building Code / CBC) expand or restate exemptions (for example, specifying refrigerant weight and motor horsepower for self-contained refrigeration) — compare § 104.2 (CMC) and § 105.2 (Existing Building Code / CBC).
How the AHJ can limit exemptions
- Exemptions do not authorize work that violates other code provisions or local laws; the AHJ may still require permits or conditions where public safety warrants it. This limitation is explicitly stated in § 104.2 and mirrored at § 105.2 in related codes.
Exceptions & special cases
Annual permits: An AHJ may allow an annual permit for a person or firm routinely performing work on the same premises in lieu of individual permits (see building/related code § 105.1.1 / CMC application requirements). Verify local adoption.
Retroactive permits and emergency repairs: Some codes provide for emergency repairs or retroactive permits (e.g., Health & Safety code cross-references). If emergency replacement is done, the permit application may be required immediately after the fact. Check local AHJ practice.
Small self-contained refrigeration: The Existing Building Code lists a numeric threshold — ≤ 10 pounds (4.54 kg) refrigerant and ≤ 1 horsepower (746 W) motor — for exemption of self-contained refrigeration systems; the CMC itself lists unit refrigerating systems as exempt but does not list the numeric refrigerant threshold in § 104.2(5). Use the Existing Building Code threshold where referenced by your jurisdiction. Bold: 10 pounds, 1 horsepower.
Work inside equipment vs. building piping: A closed piping circuit entirely inside a piece of equipment is exempt (CMC § 104.2(2)), but piping that leaves the equipment and becomes building distribution is not exempt and requires a permit. Confirm which portion of piping is inside the regulated equipment.
Replacement parts: A part-for-part replacement that does not change the equipment’s listing/approval or create unsafe conditions is exempt under § 104.2(3). If the replacement changes capacity, fuel type, controls, or safety devices, it is not exempt.
Common mistakes
Assuming "minor" always means exempt — the AHJ decides when a repair is more than minor. Exemptions are specific; do not rely on a generic sense of “small.” See § 104.2 and AHJ authority.
Confusing portable equipment with permanently installed units — a portable cooling or heating appliance is exempt, a permanently mounted HVAC unit is not. Check whether the unit is permanently connected or part of building systems. § 104.2(1).
Ignoring refrigerant-weight limits — the CMC lists unit refrigerating systems as exempt, but other California codes set numeric refrigerant and horsepower limits (e.g., 10 lb, 1 hp). Confirm the local adoption before assuming exemption.
Beginning work before obtaining permit — doing so triggers investigation fees and possible penalties under § 104.5.1 and § 104.5.2. Always check permit status first.
Failing to schedule required inspections — where a permit is required, the CMC requires inspections (underground, rough-in, final) per § 105.2 (CMC inspections section) and the permit cannot be closed without approvals.
Worked example — concrete scenario with numbers
Scenario: A homeowner replaces an old window-mounted air conditioner with a new self-contained unit in the same opening. The new unit is a listed, portable / self-contained refrigerating unit containing 5 pounds of refrigerant and uses a motor under 1 hp.
Application of the rules:
- Is the unit portable/self-contained and not permanently piped? Yes. The CMC lists portable cooling units / unit refrigerating systems as exempt (§ 104.2(1) and § 104.2(5)).
- The Existing Building Code’s numeric threshold for self-contained refrigeration is ≤ 10 lb refrigerant and ≤ 1 hp motor; this unit (5 lb, <1 hp) falls within that numeric exemption where the jurisdiction follows that text (§ 105.2 in Existing Building Code).
- Conclusion: No mechanical permit is required if the unit is indeed portable/self-contained and your local AHJ follows these exemptions. However, confirm with the AHJ because: (a) exemptions don’t allow violations of other laws, and (b) some jurisdictions may require registration or disposal documentation for refrigerants.
If instead the homeowner replaced a split-system heat pump (with refrigerant lines run through walls and connected to building piping/lines), that is a permanent installation and would require a mechanical permit under § 104.1.
Related provisions (quick list)
- § 104.1 — Permits required (CMC).
- § 104.2 — Work exempt from permit (CMC).
- § 104.3 — Application for permit; construction documents (CMC).
- § 104.4 / § 104.4.3.1 — Permit validity / expiration provisions (CMC/BSC references).
- § 104.5 / § 104.5.1 / § 104.5.2 — Fees and work commenced before permit (investigation fees) (CMC).
- § 105.0 / § 105.2 — Inspections required for permitted mechanical work (CMC inspections chapter).
- § 105.1 / § 105.2 — Permit and exemption language in the California Building Code / Existing Building Code (useful cross-reference; some numeric thresholds appear here).
Code references
Grounded in the retrieved California Mechanical Code — click a citation to read the verbatim passage:
CMC § 104.0 High relevance — show source text
104.0 Permits.
104.1 Permits Required. It shall be unlawful for a person, firm, or corporation to make an installation, alteration, repair, replacement, or remodel a mechanical system regulated by this code except as permitted in Section 104.2, or to cause the same to be done without first obtaining a separate mechanical permit for each separate building or structure.
104.2 Exempt Work. A permit shall not be required for the following:
(1) A portable heating appliance, portable ventilating equipment, a portable cooling unit, or a portable evaporative cooler.
(2) A closed system of steam, hot, or chilled water piping within heating or cooling equipment regulated by this code.
(3) Replacement of a component part that does not alter its original approval and is in accordance with other applicable requirements of this code.
(4) Refrigerating equipment that is part of the equipment for which a permit has been issued pursuant to the requirements of this code.
(5) A unit refrigerating system.
Exemption from the permit requirements of this code shall not be deemed to grant authorization for work to be done in violation of the provisions of the code or other laws or ordinances of this jurisdiction.
104.3 Application for Permit. To obtain a permit, the applicant shall first file an application therefore in writing on a form furnished by the Authority Having Jurisdiction for that purpose. Such application shall:
(1) Identify and describe the work to be covered by the permit for which application is made.
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DIVISION II SCOPE AND ADMINISTRATION
(2) Describe the land upon which the proposed work is to be done by legal description, street address, or similar description that will readily identify and definitely locate the proposed building or work.
(3) Indicate the use or occupancy for which the proposed work is intended.
(4) Be accompanied by construction documents and other data in accordance with Section 104.3.1.
(5) Be signed by the permittee or the permittee’s authorized agent. The Authority Having Jurisdiction shall be permitted to require evidence to indicate such authority.
(6) Give such other data and information in accordance with the Authority Having Jurisdiction.
104.3.1 Construction Documents. Construction documents, engineering calculations, diagrams, and other data shall be submitted in two or more sets, or in a digital format where permitted by the Authority Having Jurisdiction, with each application for a permit. The construction documents, computations, and specifications shall be prepared by, and the mechanical system designed by, a registered design professional. Construction documents shall be drawn to scale with clarity to identify that the intended work to be performed is in accordance with the code.
Exception: The Authority Having Jurisdiction shall be permitted to waive the submission of construction documents, calculations, or other data where the Authority Having Jurisdiction finds that the nature of the work applied for is such that reviewing of construction documents is not necessary to obtain compliance with the code.
104.3.2 Plan Review Fees. Where a plan or other data is required to be submitted in accordance with Section 104.3.1, a plan review fee shall be paid at the time of submitting construction documents for review.
The plan review fees for mechanical system work shall be determined and adopted by this jurisdiction.
CMC § 103.3.1 High relevance — show source text
The issuance of a permit upon construction documents shall not prevent the Authority Having Jurisdiction from thereafter requiring the correction of errors in said construction documents or from preventing construction operations being carried on thereunder where in violation of this code or of other pertinent ordinance or from revoking a certificate of approval where issued in error.
103.3.1 Licensing. Provision for licensing shall be determined by the Authority Having Jurisdiction. 103.4 Right of Entry. Where it is necessary to make an inspection to enforce the provisions of this code, or where the Authority Having Jurisdiction has reasonable cause to believe that there exists in a building or upon a premises a condition or violation of this code that makes the building or premises
unsafe, insanitary, dangerous, or hazardous, the Authority Having Jurisdiction shall be permitted to enter the building or premises at reasonable times to inspect or to perform the duties imposed upon the Authority Having Jurisdiction by this code, provided that where such building or premises is occupied, the Authority Having Jurisdiction shall present credentials to the occupant and request entry. Where such building or premises is unoccupied, the Authority Having Jurisdiction shall first make a reasonable effort to locate the owner or other person having charge or control of the building or premises and request entry. Where entry is refused, the Authority Having Jurisdiction has recourse to every remedy provided by law to secure entry.
Where the Authority Having Jurisdiction shall have first obtained an inspection warrant or other remedy provided by law to secure entry, no owner, occupant, or person having charge, care or control of a building or premises shall fail or neglect, after a request is made as herein provided, to promptly permit entry herein by the Authority Having Jurisdiction for the purpose of inspection and examination pursuant to this code.
104.0 Permits.
104.1 Permits Required. It shall be unlawful for a person, firm, or corporation to make an installation, alteration, repair, replacement, or remodel a mechanical system regulated by this code except as permitted in Section 104.2, or to cause the same to be done without first obtaining a separate mechanical permit for each separate building or structure.
104.2 Exempt Work. A permit shall not be required for the following:
(1) A portable heating appliance, portable ventilating equipment, a portable cooling unit, or a portable evaporative cooler.
(2) A closed system of steam, hot, or chilled water piping within heating or cooling equipment regulated by this code.
(3) Replacement of a component part that does not alter its original approval and is in accordance with other applicable requirements of this code.
(4) Refrigerating equipment that is part of the equipment for which a permit has been issued pursuant to the requirements of this code.
(5) A unit refrigerating system.
Exemption from the permit requirements of this code shall not be deemed to grant authorization for work to be done in violation of the provisions of the code or other laws or ordinances of this jurisdiction.
104.3 Application for Permit. To obtain a permit, the applicant shall first file an application therefore in writing on a form furnished by the Authority Having Jurisdiction for that purpose. Such application shall:
(1) Identify and describe the work to be covered by the permit for which application is made.
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DIVISION II SCOPE AND ADMINISTRATION
CMC § 104.9.1 High relevance — show source text
ADMINISTRATION
[A] 104.9.1 Materials and equipment reuse. Materials, equipment and devices shall not be reused unless such elements are in good working condition and approved.
SECTION 105—PERMITS
[A] 105.1 Required. Any owner or owner’s authorized agent who intends to repair, add to, alter, relocate, demolish or change the occupancy of a building or to repair, install, add, alter, remove, convert or replace any electrical, gas, mechanical or plumbing system, the installation of which is regulated by this code, or to cause any such work to be performed, shall first make application to the code official and obtain the required permit.
[A] 105.1.1 Annual permit. Instead of an individual permit for each alteration to an already approved electrical, gas, mechanical, or plumbing installation, the code official is authorized to issue an annual permit on application therefor to any person, firm or corporation regularly employing one or more qualified trade persons in the building, structure, or on the premises owned or operated by the applicant for the permit.
[A] 105.1.2 Annual permit records. The person to whom an annual permit is issued shall keep a detailed record of alterations made under such annual permit. The code official shall have access to such records at all times, or such records shall be filed with the code official as designated.
[A] 105.2 Work exempt from permit. Exemptions from permit requirements of this code shall not be deemed to grant authorization for any work to be done in any manner in violation of the provisions of this code or any other laws or ordinances of this jurisdiction. Permits shall not be required for the following:
Building:
- Sidewalks and driveways not more than 30 inches (762 mm) above grade and not over any basement or story below and that are not part of an accessible route.
- Painting, papering, tiling, carpeting, cabinets, counter tops and similar finish work.
- Temporary motion picture, television, and theater stage sets and scenery.
- Shade cloth structures constructed for nursery or agricultural purposes, and not including service systems.
- Window awnings supported by an exterior wall of Group R-3 or Group U occupancies.
- Nonfixed and movable cases, counters and partitions not over 5 feet 9 inches (1753 mm) in height.
Electrical:
Repairs and maintenance: Minor repair work, including the replacement of lamps or the connection of approved portable electrical equipment to approved permanently installed receptacles.
Radio and television transmitting stations: The provisions of this code shall not apply to electrical equipment used for radio and television transmissions, but do apply to equipment and wiring for power supply, the installations of towers and antennas.
Temporary testing systems: A permit shall not be required for the installation of any temporary system required for the testing or servicing of electrical equipment or apparatus.
Gas:
- Portable heating appliance.
- Replacement of any minor part that does not alter approval of equipment or make such equipment unsafe.
Mechanical:
- Portable heating appliance.
- Portable ventilation equipment.
- Portable cooling unit.
- Steam, hot or chilled water piping within any heating or cooling equipment regulated by this code.
- Replacement of any part that does not alter its approval or make it unsafe.
- Portable evaporative cooler.
- Self-contained refrigeration system containing 10 pounds (4.54 kg) or less of refrigerant and actuated by motors of 1 horsepower (746 W) or less.
CMC § 1.8.4.1 High relevance — show source text
**_ 1.8.4.1 Permits. A written construction permit shall be obtained from the enforcing agency prior to the erection, construction, reconstruction, installation, relocation, or alteration of any mechanical system. Exceptions: (1) Work exempt from permits as specified in Chapter 1, Scope and Administration, Division II, Section 104.2 Items (1) through (5) of this code. (2) Changes, alterations, or repairs of a minor nature not affecting structural features, egress, sanitation, safety, or accessibility as determined by the enforcing agency.
(3) Retroactive permits issued in accordance with Health and Safety Code Section 17958.12.
Exemptions from permit requirements shall not be deemed to grant authorization for any work to be done in any manner in violation of other provisions of law or this code. 1.8.4.2 Fees. Subject to other provisions of law, the governing body of any city, county, or city and county may prescribe fees to defray the cost of enforcement of rules and regulations promulgated by the Department of Housing and Community Development. The amount of the fees shall not exceed the amount reasonably neces- sary to administer or process permits, certificates, forms, or other documents, or to defray the costs of enforcement. For additional information, see State Housing Law, Health and Safety Code, Division 13, Part 1.5, Section 17951 and California Code of Regulations, Title 25, Divi- sion 1, Chapter 1, Subchapter 1, Article 3, commencing with Section 6.
1.8.4.3 Plan Review and Time Limitations. Subject to other provisions of law, provisions related to plan checking, prohibition of excessive delays, and contracting with or employment of private parties to perform plan checking are set forth in the State Housing Law, Health and Safety Code Section 17960.1, and for employee housing, in Health and Safety Code Section 17021. 1.8.4.3.1 Retention of Plans. The building depart- ment of every city, county, or city and county shall maintain an official copy, microfilm, or electronic or other type of photographic copy of the plans of every building, during the life of the building, for which the department issued a building permit. Exceptions: (1) Single or multiple dwellings not more than two stories and basement in height. (2) Garages and other structures appurtenant to buildings listed in Exception 1. (3) Farm or ranch buildings appurtenant to build- ings listed in Exception 1. (4) Any one-story building where the span between bearing walls does not exceed 25 feet (7620 mm), except a steel frame or concrete building. All plans for common interest developments as defined in Section 4100 of the California Civil Code shall be retained. For additional information regarding plan retention and reproduction of plans by an enforcing agency, see Health and Safety Code Sections 19850 through 19852. 1.8.4.4 Inspections. Construction or work for which a permit is required shall be subject to inspection by the building official and such construction or work shall remain accessible and exposed for inspection purposes _until approved.
CMC § 105.1 High relevance — show source text
SECTION 105—PERMITS
[A] 105.1 Required. Any owner or owner’s authorized agent who intends to construct, enlarge, alter, repair, move, demolish or change the occupancy of a building or structure, or to erect, install, enlarge, alter, repair, remove, convert or replace any electrical, gas, mechanical or plumbing system, the installation of which is regulated by this code, or to cause any such work to be performed, shall first make application to the building official and obtain the required permit.
[A] 105.1.1 Annual permit. Instead of an individual permit for each alteration to an already approved electrical, gas, mechanical or plumbing installation, the building official is authorized to issue an annual permit upon application therefor to any person, firm or corporation regularly employing one or more qualified tradespersons in the building, structure or on the premises owned or operated by the applicant for the permit.
[A] 105.1.2 Annual permit records. The person to whom an annual permit is issued shall keep a detailed record of alterations made under such annual permit. The building official shall have access to such records at all times or such records shall be filed with the building official as designated.
[A] 105.2 Work exempt from permit. Exemptions from permit requirements of this code shall not be deemed to grant authorization for any work to be done in any manner in violation of the provisions of this code or any other laws or ordinances of this jurisdiction. Permits shall not be required for the following:
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ADMINISTRATION
Building:
One-story detached accessory structures used as tool and storage sheds, playhouses and similar uses, provided that the floor area does not exceed than 120 square feet (11.15 m [2] ). It is permissible that these structures still be regulated by Section 710A, despite exemption from permit.
Fences, other than swimming pool barriers, not over 7 feet (2134 mm) high.
Oil derricks.
Retaining walls that are not over 4 feet (1219 mm) in height measured from the bottom of the footing to the top of the wall, unless supporting a surcharge or impounding Class I, II or IIIA liquids.
Water tanks supported directly on grade if the capacity is not greater than 5,000 gallons (18 925 L) and the ratio of height to diameter or width is not greater than 2:1.
Sidewalks and driveways not more than 30 inches (762 mm) above adjacent grade, and not over any basement or story below and are not part of an accessible route.
Painting, papering, tiling, carpeting, cabinets, countertops and similar finish work.
Temporary motion picture, television and theater stage sets and scenery.
Prefabricated swimming pools accessory to a Group R-3 occupancy that are less than 24 inches (610 mm) deep, are not greater than 5,000 gallons (18 925 L) and are installed entirely above ground.
Shade cloth structures constructed for nursery or agricultural purposes, not including service systems.
Swings and other playground equipment accessory to detached one- and two-family dwellings.
CMC § 104.9.1 High relevance — show source text
[A] 104.9.1 Materials and equipment reuse. Materials, equipment and devices shall not be reused unless such elements are in good working order and approved.
[A] 104.10 Other agencies. When requested to do so by the code official, other officials of this jurisdiction shall assist and cooperate with the code official in the discharge of the duties required by this code.
SECTION 105—PERMITS
[A] 105.1 General. Where not otherwise provided in the requirements of the California Building Code or California Fire Code, permits are required in accordance with Sections 105.2 through 105.10.
[A] 105.2 Permits required. Unless otherwise exempted, buildings or structures regulated by this code shall not be erected, constructed, altered, repaired, moved, removed, converted, demolished or changed in use or occupancy unless a separate permit for each building or structure has first been obtained from the code official.
For buildings or structures erected for temporary uses, see Section A108.3.
Where required by the code official, a permit shall be obtained for the following activities, operations, practices or functions within a wildland-urban interface area:
Automobile wrecking yard.
Candles and open flames in assembly areas.
Explosives or blasting agents.
Fireworks.
Flammable or combustible liquids.
Hazardous materials.
Liquefied petroleum gases.
Lumberyards.
Motor vehicle fuel-dispensing stations.
Open burning.
Pyrotechnical special effects material.
Tents, canopies and temporary membrane structures.
Tire storage.
Welding and cutting operations.
[A] 105.3 Work exempt from permit. Exemption from the permit requirements of this code or in other Parts of Title 24 shall not be deemed to grant authorization for any work to be done in any manner in violation of the provisions of this code or any other laws or ordinances of this jurisdiction.
The code official is authorized to stipulate conditions for permits. Permits shall not be issued where public safety would be at risk, as determined by the code official.
[A] 105.4 Permit application. To obtain a permit, the applicant shall first file an application therefor in writing on a form furnished by the code enforcement agency for that purpose. Every such application shall:
Identify and describe the work, activity, operation, practice or function to be covered by the permit for which application is made.
Describe the land on which the proposed work, activity, operation, practice or function is to be done by legal description, street address or similar description that will readily identify and definitely locate the proposed building, work, activity, operation, practice or function.
Indicate the use or occupancy for which the proposed work, activity, operation, practice or function is intended.
Be accompanied by plans, diagrams, computation and specifications and other data as required in Section 106 of this code.
State the valuation of any new building or structure or any addition, remodeling or alteration to an existing building.
Be signed by the applicant or the applicant’s authorized agent.
Give such other data and information as required by the code official.
[A] 105.4.1 Preliminary inspection. Before a permit is issued, the code official is authorized to inspect and approve the systems, equipment, buildings, devices, premises and spaces or areas to be used.
CMC § 101.2 High relevance — show source text
101.2 Scope . . . . . . . . . . . . . . . . . . . . . . . 21
101.3 Purpose . . . . . . . . . . . . . . . . . . . . . 21
101.4 Unconstitutional . . . . . . . . . . . . . . . 21
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TABLE OF CONTENTS
101.5 Validity . . . . . . . . . . . . . . . . . . . . . . 21
102.0 Applicability. . . . . . . . . . . . . . . . . . . 21
102.1 Conflicts Between Codes . . . . . . . . 21
102.2 Existing Installations . . . . . . . . . . . . 21
102.3 Maintenance . . . . . . . . . . . . . . . . . . 21
102.4 Additions, Alterations, Renovations, or Repairs . . . . . . . . . 21
102.5 Health and Safety . . . . . . . . . . . . . . 21
102.6 Changes in Building Occupancy. . . 21
102.7 Moved Structures . . . . . . . . . . . . . . 21
102.8 Appendices. . . . . . . . . . . . . . . . . . . 21
103.0 Duties and Powers of the
Authority Having Jurisdiction . . . . . 22
103.1 General. . . . . . . . . . . . . . . . . . . . . . 22
103.2 Liability . . . . . . . . . . . . . . . . . . . . . . 22
103.3 Applications and Permits . . . . . . . . 22
103.4 Right of Entry . . . . . . . . . . . . . . . . . 22
104.0 Permits . . . . . . . . . . . . . . . . . . . . . . 22
104.1 Permits Required . . . . . . . . . . . . . . 22
104.2 Exempt Work . . . . . . . . . . . . . . . . . 22
104.3 Application for Permit . . . . . . . . . . . 22
104.4 Permit Issuance . . . . . . . . . . . . . . . 23
104.5 Fees . . . . . . . . . . . . . . . . . . . . . . . . 24
105.0 Inspections and Testing . . . . . . . . . 24
105.1 General. . . . . . . . . . . . . . . . . . . . . . 24
105.2 Required Inspections . . . . . . . . . . . 24
105.3 Testing of Systems . . . . . . . . . . . . . 25
105.4 Connection to Service Utilities . . . . 25
106.0 Violations and Penalties . . . . . . . . . 25
106.1 General. . . . . . . . . . . . . . . . . . . . . . 25
CMC § 103.2 High relevance — show source text
103.2 Liability . . . . . . . . . . . . . . . . . . . . . . 22
103.3 Applications and Permits . . . . . . . . 22
103.4 Right of Entry . . . . . . . . . . . . . . . . . 22
104.0 Permits . . . . . . . . . . . . . . . . . . . . . . 22
104.1 Permits Required . . . . . . . . . . . . . . 22
104.2 Exempt Work . . . . . . . . . . . . . . . . . 22
104.3 Application for Permit . . . . . . . . . . . 22
104.4 Permit Issuance . . . . . . . . . . . . . . . 23
104.5 Fees . . . . . . . . . . . . . . . . . . . . . . . . 24
105.0 Inspections and Testing . . . . . . . . . 24
105.1 General. . . . . . . . . . . . . . . . . . . . . . 24
105.2 Required Inspections . . . . . . . . . . . 24
105.3 Testing of Systems . . . . . . . . . . . . . 25
105.4 Connection to Service Utilities . . . . 25
106.0 Violations and Penalties . . . . . . . . . 25
106.1 General. . . . . . . . . . . . . . . . . . . . . . 25
106.2 Notices of Correction or Violation . . 25
106.3 Penalties. . . . . . . . . . . . . . . . . . . . . 26
106.4 Stop Orders . . . . . . . . . . . . . . . . . . 26
106.5 Authority to Disconnect Utilities in Emergencies. . . . . . . . . . . . . . . . 26
106.6 Authority to Condemn. . . . . . . . . . . 26
107.0 Board of Appeals . . . . . . . . . . . . . . 26
107.1 General. . . . . . . . . . . . . . . . . . . . . . 26
107.2 Limitations of Authority . . . . . . . . . . 26
Table 104.5 Mechanical Permit Fees . . . . . . . . . 27
CHAPTER 2 DEFINITIONS. . . . . . . . . . . . . . . . . 29
201.0 General. . . . . . . . . . . . . . . . . . . . . . 31
201.1 Applicability. . . . . . . . . . . . . . . . . . . 31
202.0 Definition of Terms . . . . . . . . . . . . . 31
202.1 General. . . . . . . . . . . . . . . . . . . . . . 31
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CHAPTER 3 GENERAL REGULATIONS. . . . . . 49
301.0 General. . . . . . . . . . . . . . . . . . . . . . 51
CMC § 9.1 High relevance — show source text
R104.9.1 Materials and equipment reuse. Materials, equipment and devices shall not be reused unless such elements are in good working condition and approved.
SECTION R105—PERMITS
R105.1 Required. Any owner or owner’s authorized agent who intends to construct, enlarge, alter, repair, move, demolish or change the occupancy of a building or structure, or to erect, install, enlarge, alter, repair, remove, convert or replace any electrical, gas, mechanical or plumbing system, the installation of which is regulated by this code, or to cause any such work to be performed, shall first make application to the building official and obtain the required permit.
R105.2 Work exempt from permit. Exemption from permit requirements of this code shall not be deemed to grant authorization for any work to be done in any manner in violation of the provisions of this code or any other laws or ordinances of this jurisdiction. Permits shall not be required for the following:
Building:
Other than storm shelters, one-story detached accessory structures, provided that the floor area does not exceed 120 square feet (11.15 m [2] ). It is permissible that these structures still be regulated by Part 7 California Wildland Urban-Interface Code, despite exemption from permit.
Fences not over 7 feet (2134 mm) high.
Retaining walls that are not over 4 feet (1219 mm) in height measured from the bottom of the footing to the top of the wall, unless supporting a surcharge.
Water tanks supported directly upon grade if the capacity does not exceed 5,000 gallons (18 927 L) and the ratio of height to diameter or width does not exceed 2 to 1.
Sidewalks and driveways.
Painting, papering, tiling, carpeting, cabinets, counter tops and similar finish work.
Prefabricated swimming pools that are less than 24 inches (610 mm) deep.
Swings and other playground equipment.
Window awnings supported by an exterior wall that do not project more than 54 inches (1372 mm) from the exterior wall and do not require additional support.
Decks not exceeding 200 square feet (18.58 m [2] ) in area, that are not more than 30 inches (762 mm) above grade at any point, are not attached to a dwelling or townhouse and do not serve the exit door required by Section R318.4.
Electrical:
- Listed cord-and-plug connected temporary decorative lighting.
- Reinstallation of attachment plug receptacles but not the outlets therefor.
- Replacement of branch circuit overcurrent devices of the required capacity in the same location.
- Electrical wiring, devices, appliances, apparatus or equipment operating at less than 25 volts and not capable of supplying more than 50 watts of energy.
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DIVISION II SCOPE AND ADMINISTRATION
- Minor repair work, including the replacement of lamps or the connection of approved portable electrical equipment to approved permanently installed receptacles.
Gas:
- Portable heating, cooking or clothes drying appliances.
- Replacement of any minor part that does not alter approval of equipment or make such equipment unsafe.
- Portable-fuel-cell appliances that are not connected to a fixed piping system and are not interconnected to a power grid.
Mechanical:
CMC § 104.8 High relevance — show source text
[A] 104.8 Liability. The code official, member of the Board of Appeals, officer or employee charged with the enforcement of this code, while acting for the jurisdiction in good faith and without malice in the discharge of the duties required by this code or other pertinent law or ordinance, shall not thereby be rendered personally liable, either civilly or criminally, and is hereby relieved from personal liability for any damage accruing to persons or property as a result of any act or by reason of an act or omission in the discharge of official duties.
[A] 104.8.1 Legal defense. Any suit or criminal complaint instituted against any officer or employee because of an act performed by that officer or employee in the lawful discharge of duties and under the provisions of this code or other laws or ordinances implemented through the enforcement of this code shall be defended by legal representatives of the jurisdiction until the final termination of the proceedings. The code official or any subordinate shall not be liable for cost in any action, suit or proceeding that is instituted in pursuance of the provisions of this code.
[A] 104.9 Approved materials and equipment. Materials, equipment and devices approved by the code official shall be constructed and installed in accordance with such approval.
1-24 2025 CALIFORNIA EXISTING BUILDING CODE
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ADMINISTRATION
[A] 104.9.1 Materials and equipment reuse. Materials, equipment and devices shall not be reused unless such elements are in good working condition and approved.
SECTION 105—PERMITS
[A] 105.1 Required. Any owner or owner’s authorized agent who intends to repair, add to, alter, relocate, demolish or change the occupancy of a building or to repair, install, add, alter, remove, convert or replace any electrical, gas, mechanical or plumbing system, the installation of which is regulated by this code, or to cause any such work to be performed, shall first make application to the code official and obtain the required permit.
[A] 105.1.1 Annual permit. Instead of an individual permit for each alteration to an already approved electrical, gas, mechanical, or plumbing installation, the code official is authorized to issue an annual permit on application therefor to any person, firm or corporation regularly employing one or more qualified trade persons in the building, structure, or on the premises owned or operated by the applicant for the permit.
[A] 105.1.2 Annual permit records. The person to whom an annual permit is issued shall keep a detailed record of alterations made under such annual permit. The code official shall have access to such records at all times, or such records shall be filed with the code official as designated.
[A] 105.2 Work exempt from permit. Exemptions from permit requirements of this code shall not be deemed to grant authorization for any work to be done in any manner in violation of the provisions of this code or any other laws or ordinances of this jurisdiction. Permits shall not be required for the following:
CMC § 104.4.3.1 High relevance — show source text
DIVISION II SCOPE AND ADMINISTRATION
made or will be made in the original construction documents for such work, and provided further that such suspension or abandonment has not exceeded 1 year. 104.4.3.1 Expiration. [BSC] On or after January 1, 2019, every permit issued shall become invalid unless the work on the site authorized by such per- mit is commenced within 12 months after its issuance or if the work authorized on the site by such permit is suspended or abandoned for a period of 12 months after the time the work is commenced. The building official is authorized to grant, in writ- ing, one or more extensions of time, for periods not more than 180 days each. The extension shall be requested in writing and justifiable cause demon- strated. (See Health and Safety Code Section 18938.5 and 18938.6). 104.4.4 Extension. A permittee holding an unexpired permit shall be permitted to apply for an extension of the time within which work shall be permitted to commence under that permit where the permittee is unable to commence work within the time required by this section. The Authority Having Jurisdiction shall be permitted to extend the time for action by the permittee for a period not exceeding 180 days upon written request by the permittee showing that circumstances beyond the control of the permittee have prevented action from being taken. No permit shall be extended more than once. In order to renew action on a permit after expiration, the permittee shall pay a new full permit fee. 104.4.5 Suspension or Revocation. The Authority Having Jurisdiction shall be permitted, with written notification, to suspend or revoke a permit issued under the provisions of this code where the permit is issued in error or on the basis of incorrect information supplied or in violation of other ordinance or regulation of the jurisdiction.
104.4.6 Retention of Plans. One set of approved construction documents and computations shall be retained by the Authority Having Jurisdiction until final approval of the work is covered therein.
One set of approved construction documents, computations, and manufacturer’s installation instructions shall be returned to the applicant, and said set shall be kept on the site of the building or work at times during which the work authorized thereby is in progress.
104.5 Fees. Fees shall be assessed in accordance with the provisions of this section and as set forth in the fee schedule, Table 104.5. The fees are to be determined and adopted by this jurisdiction. 104.5.1 Work Commencing Before Permit Issuance. Where work for which a permit is required by this code has been commenced without first obtaining said permit, a special investigation shall be made before a permit is issued for such work. 104.5.2 Investigation Fees. An investigation fee, in addition to the permit fee, shall be collected whether or not a permit is then or subsequently issued. The investigation fee shall be equal to the amount of the permit fee
that is required by this code if a permit were to be issued. The payment of such investigation fee shall not exempt a person from compliance with other provisions of this code, nor from a penalty prescribed by law. 104.5.3 Fee Refunds. The Authority Having Jurisdiction shall be permitted to authorize the refunding of a fee as follows:
(1) The amount paid hereunder that was erroneously paid or collected.
CMC § 104.7.4 High relevance — show source text
[A] 104.7.4 Tests. The building official shall keep a record of tests conducted to comply with Sections 104.2.2.4 and 104.2.3.5.
[A] 104.7.5 Fees. The building official shall keep a record of fees collected and refunded in accordance with Section 109.
[A] 104.8 Liability. The building official, member of the board of appeals or employee charged with the enforcement of this code, while acting for the jurisdiction in good faith and without malice in the discharge of the duties required by this code or other pertinent law or ordinance, shall not thereby be rendered personally liable, either civilly or criminally, and is hereby relieved from personal liability for any damage accruing to persons or property as a result of any act or by reason of any act or omission in the discharge of official duties.
[A] 104.8.1 Legal defense. Any suit or criminal complaint instituted against any officer or employee because of an act performed by that officer or employee in the lawful discharge of duties under the provisions of this code or other laws or ordinances implemented through the enforcement of this code shall be defended by legal representatives of the jurisdiction until the final termination of the proceedings. The building official or any subordinate shall not be liable for costs in an action, suit or proceeding that is instituted in pursuance of the provisions of this code.
[A] 104.9 Approved materials and equipment. Materials, equipment and devices approved by the building official shall be constructed and installed in accordance with such approval.
[A] 104.9.1 Materials and equipment reuse. Materials, equipment and devices shall not be reused unless such elements are in good working condition and approved.
SECTION 105—PERMITS
[A] 105.1 Required. Any owner or owner’s authorized agent who intends to construct, enlarge, alter, repair, move, demolish or change the occupancy of a building or structure, or to erect, install, enlarge, alter, repair, remove, convert or replace any electrical, gas, mechanical or plumbing system, the installation of which is regulated by this code, or to cause any such work to be performed, shall first make application to the building official and obtain the required permit.
[A] 105.1.1 Annual permit. Instead of an individual permit for each alteration to an already approved electrical, gas, mechanical or plumbing installation, the building official is authorized to issue an annual permit upon application therefor to any person, firm or corporation regularly employing one or more qualified tradespersons in the building, structure or on the premises owned or operated by the applicant for the permit.
[A] 105.1.2 Annual permit records. The person to whom an annual permit is issued shall keep a detailed record of alterations made under such annual permit. The building official shall have access to such records at all times or such records shall be filed with the building official as designated.
[A] 105.2 Work exempt from permit. Exemptions from permit requirements of this code shall not be deemed to grant authorization for any work to be done in any manner in violation of the provisions of this code or any other laws or ordinances of this jurisdiction. Permits shall not be required for the following:
2025 CALIFORNIA BUILDING CODE 1-27
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ADMINISTRATION
Frequently asked questions
Do I always need a permit to replace a furnace filter or blower motor?
No — simple maintenance like replacing filters or an identical component that does not alter the equipment’s original approval is exempt under § 104.2(3). If the replacement changes capacity, safety controls, fuel type, or modifies the system, it is not exempt and may require a permit.
My contractor says the job is “minor” and no permit is needed. Can the AHJ disagree?
Yes. The AHJ has authority to determine whether a change is minor. Exemptions are specific; the AHJ can require a permit if public safety or code compliance is affected. See the limitation language in § 104.2.
Are there numeric refrigerant limits that make refrigeration exempt?
The CMC lists unit refrigerating systems as exempt in § 104.2(5). The Existing Building Code explicitly identifies self-contained refrigeration systems containing 10 pounds (4.54 kg) or less of refrigerant and actuated by motors of 1 horsepower (746 W) or less as exempt; use that numeric guidance where your jurisdiction applies it.
What happens if I start work before getting a permit?
The AHJ may require a special investigation and charge an investigation fee equal to the permit fee in addition to the regular permit fee; work without permit does not relieve you from compliance responsibilities or penalties (§ 104.5.1, § 104.5.2).
Who issues the permit and where do I get plans?
Permits are issued by the Authority Having Jurisdiction (AHJ). The permit application must identify the work and be accompanied by construction documents when required (see § 104.3). The AHJ can waive plan submittal for minor work at its discretion.
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