CRC · California Residential Code
Definitions
Chapter 2 (§R201–§R202) is the CRC's definitions and interpretation chapter and should be consulted first to determine the meaning and applicability of terms.
Last reviewed: July 6, 2026
Overview
Chapter 2 of the California Residential Code is the chapter that collects the code's defined terms and the rules for how words are to be interpreted. It is the authoritative reference for phrases used elsewhere in the CRC and explains scope, interchangeability, and where undefined terms get their meaning. See Part II — Chapter 2 and its table of contents listing R201 and R202 for the chapter organization.
Key provisions are found in Section R201 (General provisions on scope, interchangeability and cross‑references) and Section R202 (the alphabetical list of defined terms). These sections are consulted first when a term's meaning affects applicability or compliance with other CRC sections.
In this section
Code references
Grounded in the retrieved California Residential Code — click a citation to read the verbatim passage:
CRC § 2-5 High relevance — show source text
Part II—Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-5
CHAPTER 2 DEFINITIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . .2-5
R201 General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5
R202 Definitions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5
Part III—Building Planning and Construction . . . . . . . . . . . .3-5
CHAPTER 3 BUILDING PLANNING . . . . . . . . . . . . . . . . . . . . .3-5
R300 Site Drainage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5
R301 Design Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5
R302 Fire-Resistant Construction . . . . . . . . . . . . . . . . . . . . 3-23
R303 Foam Plastic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-31
R304 Protection of Wood and Wood-Based Products
Against Decay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-33
R305 Protection Against Subterranean Termites. . . . . . . 3-35
R306 Flood-Resistant Construction. . . . . . . . . . . . . . . . . . . 3-36
R307 Storm Shelters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-40
R308 Site Address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-40
R309 Automatic Sprinkler Systems . . . . . . . . . . . . . . . . . . . 3-41
R310 Smoke Alarms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-54
R311 Carbon Monoxide Alarms. . . . . . . . . . . . . . . . . . . . . . . 3-58
R312 Minimum Room Areas . . . . . . . . . . . . . . . . . . . . . . . . . 3-59
R313 Ceiling Height . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-59
CRC § 1-18 High relevance — show source text
R104 Duties and Powers of the Building Official . . . . . . . 1-18
R105 Permits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-20
R106 Construction Documents . . . . . . . . . . . . . . . . . . . . . . 1-22
R107 Temporary Structures and Uses . . . . . . . . . . . . . . . . 1-23
R108 Fees . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-23
R109 Inspections. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-23
R110 Certificate of Occupancy. . . . . . . . . . . . . . . . . . . . . . . 1-25
R111 Service Utilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-25
R112 Means of Appeals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-25
R113 Violations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-26
R114 Stop Work Order . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-26
Part II—Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-5
CHAPTER 2 DEFINITIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . .2-5
R201 General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5
R202 Definitions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5
Part III—Building Planning and Construction . . . . . . . . . . . .3-5
CHAPTER 3 BUILDING PLANNING . . . . . . . . . . . . . . . . . . . . .3-5
R300 Site Drainage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5
R301 Design Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5
R302 Fire-Resistant Construction . . . . . . . . . . . . . . . . . . . . 3-23
CRC § 2.4 High relevance — show source text
Court Emergency escape and rescue openings R319.1, R319.2.4 Means of egress R318.1 Natural light R325.1.1 Covering Exterior R703
Interior R702 Roof Chapter 9 Wall Chapter 7 Crawl Space R408
Access R408.4
Damper Fireplace R1001.7.1 Dampproofing R406 Day Care Appendix BD Defined R202 Large family day-care homes R336 Dead Loads R301.4
Decay Protection against R304 Deck
Attachment R318.5 Supported by exterior wall R507 Wood/plastic composite boards R507.2.2
Definitions Building R202 Mechanical system R202 Plumbing R202 Design Criteria R301 Alternative provisions R301.1.1 Application R301.1 Climatic and geographic R301.2 Dead load R301.4
Deflection R301.6 Engineered design R301.1.3
Accessibility R322 Accessory Dwelling Unit R202 Authority to Enforce Automatic Fire Sprinkler Systems 1.8.9.1, R313.2 Accessory Structure Elevations R306.3.2
Energy R330.5 Exterior walls R302.1
Scope R101.2 Addition (see also Existing Buildings) Carbon monoxide alarms R311.2.2 Change of occupancy R110.1 Construction R302.2.3
Frost protection R403.1.4.1 Scope R101.2, R102.6.1 Smoke alarms R310.2.2 Address (Site) R308 Administration, California Chapter 1, Division 1
General 1.1 Dept. of Housing and Community Development 1.8 Office of the State Fire Marshal 1.11 Administration, Division II Chapter 1 Applicability R102 Certificate of occupancy R110 Construction documents R106 Department of building safety R103 Duties and Powers R104
Fees R106
Inspections R109 Means of appeals R112 Permits R105, R105.5.1 Purpose R101.3 Service utilities R111 Stop work order R114 Temporary structures and uses R107 Violations R113 Aging-in-place Design and Fall Prevention R327
Doorbell buttons R327.1.4 Electrical receptacle outlet, switch and control heights R327.1.2 Interior doors R327.1.3 Reinforcement for grab bars R327.1.1 Allowable Spans Of floor joists R502.3, R505.3.2 Of headers R602.7, R603.6 Of rafters and ceiling joists R802.4, R802.5, R804.3.1, R804.3.2 Alternate Materials (see Materials) R104.11 Alterations (see Existing Buildings) Anchor Bolts R403.1.6
Appeal Board of 1.8.8, Appendix AA Means of 1.8.8, R112 Appliance Flue area R1003.14
CRC § 2025 High relevance — show source text
It is important to understand that the IRC contains coverage for what is conventional and common in residential construction practice. While the IRC will provide all of the needed coverage for most residential construction, it might not address construction practices and systems that are atypical or rarely encountered in the industry. Therefore, the IRC contains several references to other codes either as an alternative to the provisions of the IRC or where the IRC lacks coverage for a particular type of structure, design, system, appliance or method of construction. In other words, the IRC is meant to be all inclusive for typical residential construction and it relies on other codes only where alternatives are desired or where the code lacks coverage for the uncommon aspect of residential construction. Of course, the IRC constantly evolves to address new technologies and construction practices that were once uncommon, but are now common.
The IRC is unique in that much of it, including Chapters 3 through 9 and Chapters 34 through 43, is presented in an ordered format that is consistent with the normal progression of construction, starting with the design phase and continuing through the final trimout phase. This is consistent with the “cookbook” philosophy of the IRC.
2025 CALIFORNIA RESIDENTIAL CODE xiii
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
xiv 2025 CALIFORNIA RESIDENTIAL CODE
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
Arrangement and Format of the 2025 CRC
The CRC is divided into nine main parts, specifically: Part I—Administrative, Part II—Definitions, Part III—Building Planning and Construction, Part IV—Energy Conservation, Part V—Mechanical, Part VI—Fuel Gas, Part VII—Plumbing, Part VIII—Electrical and Part IX—Referenced Standards. Parts IV through VIII of IRC are not adopted in California and replaced with references to appropriate parts of Title 24. The following provides a brief description of the content of each chapter and appendix of the CRC:
Chapter 1 Scope and Administration.
Chapter 1 establishes the limits of applicability of the code and describes how the code is to be applied and enforced. 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 design professional, contractor and property owner.
Chapter 2 Definitions.
Chapter 2 is the repository of the definitions of terms used in the body of the code. The user of the code should be familiar with and consult this chapter because the definitions are essential to the correct interpretation of the code and because the user may not be aware that a term is defined.
Chapter 3 Building Planning.
Chapter 3 provides guidelines for a minimum level of structural integrity, life safety, fire safety and livability for inhabitants of dwelling units regulated by this code. Chapter 3 is a compilation of the code requirements specific to the building planning sector of the design and construction process. This chapter sets forth code requirements dealing with light, ventilation, sanitation, minimum room size, ceiling height and environmental comfort. Chapter 3 establishes life-safety provisions including limitations on glazing used in hazardous areas, specifications on stairways, use of guards at elevated surfaces, window and fall protection, and rules for means of egress. Snow, wind and seismic design live and dead loads and flood-resistant construction, as well as solar energy systems are addressed in this chapter.
Chapter 4 Foundations.
CRC § 9.1 High relevance — show source text
Defined R202 Chimneys Caps R1003.9.1 Clearance R1003.18 Corbeling R1003.5 Crickets R1003.20 Design (masonry) R1003.1 Factory-built R1005 Fireblocking R1003.19 Fireplaces Chapter 10 Flue area R1003.14, R1003.15 Flue lining R1003.11 Load R1003.8 Multiple flue R1003.14 Rain caps R1003.9.3 Spark arrestors R1003.9.2 Termination R1003.9
Wall thickness R1003.10
Clay Tiles R905.3
Cleanout Masonry chimney R1003.17 Climate Types R301.2 Climate Zones R202, R702.7.3, Table R702.7(5) Columns R407
2025 CALIFORNIA RESIDENTIAL CODE INDEX-1
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
INDEX
Live load R301.5
Nominal sizes R301.8
Roof load R301.6
Seismic R301.2.2
Snow loads R301.2.3 Story height R301.3 Sunrooms R301.2.1.1.1
Wind R301.2.1
Doors
Egress R318.2 Exterior R318.3, R609 Glazing R324 Draftstopping R302.12, R502.13 Drainage Foundation R405 Site drainage R300 Ducts
Defined R202 Dwelling-garage wall and ceiling penetration R302.5.2 System, definition R202 Dwelling Unit Separation R302.2, R302.3 Sprinklers (see Automatic Sprinkler System)
Electric Vehicle Charging Stations R317.6 Elevator R323.1, R323.3 Emergency Escape and Rescue Openings R319
Additions R319.6
Area wells R319.4 Bars, grilles, covers and screens R319.4.4
Basements, existing R319.7 Dimensions R319.2
Doors R319.3
Replacement window R319.5 Under decks and porches R319.2.4 Where required R319.1 Window fall protection R321.2 Emergency Housing Appendix CJ Energy Storage Systems R328 ESS vehicle impact protection Figure R330.8.1 Maximum aggregate ratings of ESS Table R330.5 Protection from impact R330.8 Toxic and highly toxic gas R330.12 Entry 1.8.5, R104.4 Existing Buildings Appendix BO Administrative R101.2, R102.6, R105.1, R105.8, R106.2, R113.1, R113.2 Basements R313.1.2, R319.7 Carbon monoxide alarms R311.2.2, R311.5, R311.6 Flood R104.3.1
CRC § 8.4 Medium relevance — show source text
Floor R503.3
Walls R605 Patio Covers Appendix BF Penetrations R302.4, R302.5 Permits 1.8.4, R105, R105.5.1 Permit fees Appendix AB Photovoltaic Panel Systems R907 Ground-mounted definition R202
Photovoltaic Support Structure, Elevated R202, R324.8, R324.8.1, R324.8.2 Piers R606.7
Masonry R404.1.9 Planning Building Chapter 3 Plans R106
Plaster
Exterior R703.7
Interior R702.2
Platform Lifts R323.2, R323.3 Plumbing Fixture clearances R327
Fixtures R326, R327 Inspection 109.1.2 Requirements and definitions R202 System, definition R202 Plywood Application R703.5 Materials, walls R604
Precast Concrete
Footings R403.4 Foundation material R402.3.1
Foundation walls R404.5
Protection Against decay and termites R304, R305 Against radon Appendix BE Public Way R318.1, R319.1 Purlins R802.4.5
Hot Tubs (see Swimming Pools) R324.3.1, R328 Hurricane (see Storm Shelter)
Impact Protective System Energy storage system R330.8 Flood R306.1.4.2, R306.3.3 Human impact R324.3 Storm shelter R307.2.1
Windborne debris R301.2.1.2 Indirectly Conditioned Space (see Conditioned Space) Inflatable Amusement Device
Defined R202
Inlet To masonry chimneys R1003.16 Inspection On-site 1.8.4, R109.1 Insulation
Above-deck R906 Flame spread R302.10 Foam plastic R303 Interior
Lath R702.2.3
Other finishes R702.5
Plaster R702.2 Wall covering Chapter 7 Intermodal Shipping Container R301.1.4
Joist
Bearing R502.6, R606.6.3.1
Kitchen Height and area R312, R313 Sinks R326
Ventilation R325.1.2
Labeling Garage doors R609.4.1 Ladders
Ships ladders R318.7.13 Sleeping lofts R315.5.3 Landings (see also Stairways, Ramps and Doors) R318.3, R318.3.1, R318.3.2, R318.7.6, R318.8.2, R321, R324.4.7, R325.6, R325.7 Lateral Support R502.7, R606.6.4, R607.5.2 Lath
Exterior R703.7.1
Interior R702.2.3
Lavatories R326.1
Clearances R327 Liability R104.8 Light R325 Lighting Adjoining rooms R325.1.3 Bathrooms R325.2
CRC § 1.11 Medium relevance — show source text
R201.2 Interchangeability. Words used in the present tense include the future; words in the masculine gender include the feminine and neuter; the singular number includes the plural and the plural, the singular.
R201.3 Terms defined in other codes. Where terms are not defined in this code such terms shall have the meanings ascribed in the California Building Standards Code, Title 24, California Code of Regulations.
R201.4 Terms not defined. Where terms are not defined through the methods authorized by this section, such terms shall have ordinarily accepted meanings such as the context implies.
For applications listed in Section 1.11 regulated by the Office of the State Fire Marshal, where terms are not defined through the meth- ods authorized by this section, such terms shall have ordinarily accepted meanings such as the context implies. Webster’s Third New International Dictionary of the English Language, Unabridged, shall be considered as providing ordinarily accepted meanings.
SECTION R202—DEFINITIONS
[RB] ACCESS (TO). That which enables a device, an appliance or equipment to be reached by ready access or by a means that first requires the removal or movement of a panel, door or similar obstruction.
ACCESSORY DWELLING UNIT. [HCD 1 & HCD 2] An attached or detached residential dwelling unit that provides complete independent living facilities for one or more persons and is located on a lot with a proposed or existing primary residence. Accessory dwelling units shall include permanent provisions for living, sleeping, eating, cooking and sanitation on the same parcel as the single-family or multifamily dwelling is or will be situated. (See Government Code Section 65852.2)
[RB] ACCESSORY STRUCTURE. A structure that is accessory to and incidental to that of the dwelling(s) or townhouse(s) and that is located on the same lot.
[RB] ADDITION. An extension or increase in floor area, number of stories or height of a building or structure.
[RB] ADHERED STONE OR MASONRY VENEER. Stone or masonry veneer secured and supported through the adhesion of an approved bonding material applied to an approved backing.
AGED HOME OR INSTITUTION. A facility used for the housing of persons 65 years of age or older in need of care and supervision. (See defi- nition of “care and supervision.”)
[MP] AIR, OUTDOOR. Ambient air that enters a building through a ventilation system, through intentional openings for natural ventilation or by infiltration.
[MP] AIR, TRANSFER. Air moved from one indoor space to another.
[MP] AIR ADMITTANCE VALVE. A one-way valve designed to allow air into the plumbing drainage system where a negative pressure develops in the piping. This device shall close by gravity and seal the terminal under conditions of zero differential pressure (no flow conditions) and under positive internal pressure.
[MP] AIR BREAK (DRAINAGE SYSTEM). An arrangement where a discharge pipe from a fixture, appliance or device drains indirectly into a receptor below the flood-level rim of the receptor and above the trap seal.
[MP] AIR CIRCULATION, FORCED. A means of providing space conditioning utilizing movement of air through ducts or plenums by mechanical means.
[MP] AIR GAP, DRAINAGE SYSTEM. The unobstructed vertical distance through free atmosphere between the outlet of a waste pipe and the flood-level rim of the fixture or receptor into which it is discharging.
CRC § 2.3.1 Medium relevance — show source text
2025 CALIFORNIA RESIDENTIAL CODE APPENDIX CK-7
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
APPENDIX CK-8 2025 CALIFORNIA RESIDENTIAL CODE
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
2025 CALIFORNIA RESIDENTIAL CODE APPENDIX NA-1
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
APPENDIX NA-2 2025 CALIFORNIA RESIDENTIAL CODE
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
Concrete Capillary break R506.2.3.1 Compressive strength R402.2 Floors (on ground) R506 Tile (roof) R905.3 Weathering Figure R301.2(1), R402.2 Construction
3D-printed Appendix BM Cavity wall masonry R608 Cob Appendix BK Extended plate walls Appendix BN Flood-resistant R306
Floors Chapter 5 Footings R403 Foundation material R402
Foundation walls R404
Foundations Chapter 4 Hemp-lime Appendix BL Masonry R606, R607, R608, R610 Pollutant control R340 Roofs Chapter 8 Steel framing R505, R603, R804 Strawbale Appendix BJ Straw-clay Appendix BI Walls Chapter 6 Waste R334.1 Wood framing R502, R602, R802 Construction Documents R106, R306.3.9
Court Emergency escape and rescue openings R319.1, R319.2.4 Means of egress R318.1 Natural light R325.1.1 Covering Exterior R703
Interior R702 Roof Chapter 9 Wall Chapter 7 Crawl Space R408
Access R408.4
Damper Fireplace R1001.7.1 Dampproofing R406 Day Care Appendix BD Defined R202 Large family day-care homes R336 Dead Loads R301.4
Decay Protection against R304 Deck
Attachment R318.5 Supported by exterior wall R507 Wood/plastic composite boards R507.2.2
Definitions Building R202 Mechanical system R202 Plumbing R202 Design Criteria R301 Alternative provisions R301.1.1 Application R301.1 Climatic and geographic R301.2 Dead load R301.4
Deflection R301.6 Engineered design R301.1.3
Accessibility R322 Accessory Dwelling Unit R202 Authority to Enforce Automatic Fire Sprinkler Systems 1.8.9.1, R313.2 Accessory Structure Elevations R306.3.2
Energy R330.5 Exterior walls R302.1
Scope R101.2 Addition (see also Existing Buildings) Carbon monoxide alarms R311.2.2 Change of occupancy R110.1 Construction R302.2.3
CRC § 2-3 Medium relevance — show source text
SYSTEM||||X|||||||||||||||||||| |VENTILATION||||X|||||||||||||||||||| |WATER HEATER||||X|||||||||||||||||||| |WHOLE-HOUSE MECHANICAL
VENTILATION SYSTEM||||X|||||||||||||||||||| |WILDLAND-URBAN INTERFACE (WUI)|||X|||||||||||||||||||||The state agency does not adopt sections identified with the following symbol: †
2025 CALIFORNIA RESIDENTIAL CODE 2-3
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
2-4 2025 CALIFORNIA RESIDENTIAL CODE
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
Part II—Definitions
2 DEFINITIONS
User notes:
About this chapter: Codes, by their very nature, are technical documents. Every word, term and punctuation mark can add to or change the meaning of a technical requirement. It is necessary to maintain a consensus on the specific meaning of each term contained in the code. Chapter 2 performs this function by stating clearly what specific terms mean for the purpose of the code.
ICC code development note: Code change proposals to definitions in this chapter preceded by a bracketed letter are considered by the IRC—Building Code Development Committee [RB], the IRC—Mechanical/Plumbing Code Development Committee [MP] or the IECC—Residential Code Development Committee [RE] during the Group B (2025) Code Development Cycle.
SECTION R201—GENERAL
R201.1 Scope. Unless otherwise expressly stated, the following words and terms shall, for the purposes of this code, have the meanings indicated in this chapter.
R201.2 Interchangeability. Words used in the present tense include the future; words in the masculine gender include the feminine and neuter; the singular number includes the plural and the plural, the singular.
R201.3 Terms defined in other codes. Where terms are not defined in this code such terms shall have the meanings ascribed in the California Building Standards Code, Title 24, California Code of Regulations.
R201.4 Terms not defined. Where terms are not defined through the methods authorized by this section, such terms shall have ordinarily accepted meanings such as the context implies.
For applications listed in Section 1.11 regulated by the Office of the State Fire Marshal, where terms are not defined through the meth- ods authorized by this section, such terms shall have ordinarily accepted meanings such as the context implies. Webster’s Third New International Dictionary of the English Language, Unabridged, shall be considered as providing ordinarily accepted meanings.
SECTION R202—DEFINITIONS
[RB] ACCESS (TO). That which enables a device, an appliance or equipment to be reached by ready access or by a means that first requires the removal or movement of a panel, door or similar obstruction.
ACCESSORY DWELLING UNIT. [HCD 1 & HCD 2] An attached or detached residential dwelling unit that provides complete independent living facilities for one or more persons and is located on a lot with a proposed or existing primary residence. Accessory dwelling units shall include permanent provisions for living, sleeping, eating, cooking and sanitation on the same parcel as the single-family or multifamily dwelling is or will be situated. (See Government Code Section 65852.2)
CRC § 2.3 Medium relevance — show source text
SIP R610.8
Steel R603.6
Wood R602.7
Hearth R1001.9
Extension R1001.10, R1001.9
Heaters
Masonry R1002 Heating Required R325.8 Height Ceiling R313 Mezzanines R314.2 Sleeping lofts R315.3 Hollow-Unit Masonry (see Masonry)
INDEX-2 2025 CALIFORNIA RESIDENTIAL CODE
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
INDEX
Roof shingles R905.4 Methods Water distribution pipe sizing Appendix CF Mezzanines (see also Sleeping Lofts) R314, R321 Modifications R104.2.3 Moisture Content, Building Materials R109.1.4.1
Moisture Control R702.7
Mortar
Joints R606.3.1 Multiple Flues R1003.13
Natural Light (see Light) Natural Ventilation (see Ventilation) Notching Steel joists R505.2.5, R505.3.5, R804.2.5, R804.3.3 Steel studs R603.2.6, R603.3.4 Wood joists R502.8, R802.7.1 Wood studs R602.6 Wood top plates R602.6.1
Opening Protection R302.5
Parapets R302.2.2, R606.4.4 Particleboard
Floor R503.3
Walls R605 Patio Covers Appendix BF Penetrations R302.4, R302.5 Permits 1.8.4, R105, R105.5.1 Permit fees Appendix AB Photovoltaic Panel Systems R907 Ground-mounted definition R202
Photovoltaic Support Structure, Elevated R202, R324.8, R324.8.1, R324.8.2 Piers R606.7
Masonry R404.1.9 Planning Building Chapter 3 Plans R106
Plaster
Exterior R703.7
Interior R702.2
Platform Lifts R323.2, R323.3 Plumbing Fixture clearances R327
Fixtures R326, R327 Inspection 109.1.2 Requirements and definitions R202 System, definition R202 Plywood Application R703.5 Materials, walls R604
Precast Concrete
Footings R403.4 Foundation material R402.3.1
Foundation walls R404.5
Protection Against decay and termites R304, R305 Against radon Appendix BE Public Way R318.1, R319.1 Purlins R802.4.5
Hot Tubs (see Swimming Pools) R324.3.1, R328 Hurricane (see Storm Shelter)
Impact Protective System Energy storage system R330.8 Flood R306.1.4.2, R306.3.3 Human impact R324.3 Storm shelter R307.2.1
CRC § 2.5 Medium relevance — show source text
Parapet construction R302.2.5 Scope R101.2 Separation R302.2 Structural independence R302.2.6 Trusses
Steel R505.1.3, R804.3.6 Wood R502.12, R802.10 Tubular Daylighting Device (TDD) (see Skylights) Two-Family Dwellings R302.3
Under Floor
Space R408
Vapor Retarders R702.7 Capillary break R506.2.3.1 Under floor R408.8 Vehicular Gates Appendix BH Veneer
Masonry R703.7 Ventilation Adjoining rooms R325.1.3 Bathroom and kitchen R325.2
Habitable rooms R325.1
Roof R806
Under floor R408.1 Venting (Mechanical) Chimney and vent connectors R1006 Fireplace R1006 General R325.3
Violations R113 Visible Transmittance (VT)
Wall Furnace (see Appliance) Wallboard (see Gypsum) Walls
Bathtub compartments R327.2 Bracing, steel R603.9 Bracing, wood R602.10 Construction Chapter 6 Covering Chapter 7 Crawl space R202 Cripple R602.9
INDEX-4 2025 CALIFORNIA RESIDENTIAL CODE
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
INDEX
Deflection R301.7
Exterior, defined R202 Exterior covering R703 Finishes R327.2, R702 Fireplace R1001.5 Foundation R404 Insulating concrete form R608.3, R608.4, R608.5.3 Steel framing R603 Structural insulated panels (SIP) R610 Thickness, masonry chimneys R1003.10 Wood framing R602 Waste
Construction waste R334
Water Closet R326.1, R327 Clearances for R327.1 Waterproofing And dampproofing R406 Wells (see Individual Water Supply) Whirlpool Bathtubs R324.3.1, P2720 Wind
Design criteria R301.2, R301.2.1 Speed maps Figure R301.2(2) Window R609 Emergency Escape and Rescue Openings R319, R321.2.2 Fall protection R321.2 Glazing R324 Light and ventilation R325 Opening limiting devices R321.2.2 Wood
Floor construction R502
Foundation walls R404.2 Protection against decay R304 Roof-ceiling construction R802 Shakes R905.8 Shingles R905.7 Trusses R502.12, R802.10 Walls R602
Yard R318.1, R319.1, R319.2.4, R325.1.1
2025 CALIFORNIA RESIDENTIAL CODE INDEX-5
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
INDEX-6 2025 CALIFORNIA RESIDENTIAL CODE
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
HISTORY NOTE APPENDIX
CRC § 1.5 Medium relevance — show source text
Adopting agency BSC BSC-
CGSFM HCD Col6 Col7 DSA Col9 Col10 OSHPD Col12 Col13 Col14 Col15 Col16 BSCC DPH AGR DWR CEC CA SL SLC Adopting agency BSC BSC-
CGSFM 1 2 1/AC AC SS SS/CC 1 1R 2 3 4 5 5 5 5 5 5 5 5 5 Adopt entire chapter Adopt entire chapter as
amended (amended
sections listed below)Adopt only those sections
that are listed belowX X X Chapter / Section R109.1.5 X X R109.1.5.1 X X R109.1.5.2 X R109.1.5.3 X R109.1.6 X X R109.1.6.1 X R109.1.6.2 X R109.2 - R109.4 X R110 - R110.4 X R111 - R111.3 X R113.1 - R113.2 X R114.1 - R114.4 X The state agency does not adopt sections identified with the following symbol: †
1-2 2025 CALIFORNIA RESIDENTIAL CODE
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
PART I—ADMINISTRATIVE
1 ADMINISTRATION
DIVISION I CALIFORNIA ADMINISTRATION
SECTION 1.1—GENERAL
1.1.1 Title. These regulations shall be known as the California Residential Code, may be cited as such and will be referred to herein as “this code.” The California Residential Code is Part 2.5 of thirteen parts of the official compilation and publication of the adoption, amendment and repeal of building regulations to the California Code of Regulations, Title 24, also referred to as the California Building Standards Code. This part incorporates by adoption the 2024 International Residential Code of the International Code Council with necessary California amendments.
Frequently asked questions
Where in the CRC do I look first for a definition?
Start with Chapter 2 — Section R202 contains the list of defined terms; Section R201 explains scope and interpretation rules.
What if a term is not defined in Chapter 2?
Section R201.3 directs you to definitions in other parts of Title 24 when applicable, and R201.4 says ordinarily accepted meanings apply when no code definition exists.
Why are definitions important for plan review and enforcement?
Definitions control how requirements apply (who, what, where, and when). Misreading a defined term can change permit scope or compliance paths, so Chapter 2 is the first stop when a term matters.
More in California Residential Code
Ask about the CRC
Get cited, plain-English answers on the California Residential Code for your project — any code section, any scenario.
Start Free Trial