CRC · California Residential Code
What counts as 'Habitable Space'?
A space is “habitable” under the CRC only if it’s intended for living, sleeping, eating or cooking; bathrooms, closets, halls, storage and utility areas are excluded. Start with the definition in **§ R202** and then apply the habitable‑room rules (minimum ceiling height § R313, light & ventilation § R325, and related sections) before you count a room as habitable.
Last reviewed: July 6, 2026
What the code requires — 2-4 sentences
The California Residential Code defines Habitable Space as a space used for living, sleeping, eating, or cooking. Spaces such as bathrooms, toilet rooms, closets, halls, storage or utility spaces and similar areas are not habitable. The controlling definition is § R202.
The single most important rule: a room is “habitable” only if it is intended for living, sleeping, eating or cooking — if it’s a bathroom, closet, hall, storage, utility room or similar, do not count it as habitable.
Requirements in detail
Core definition (what is in / out)
- Included: spaces for living, sleeping, eating, cooking.
- Excluded: bathrooms, toilet rooms, closets, halls, storage or utility spaces, and “similar areas.”
Reference: § R202.
Decision-relevant dimensions and minimums
| Decision question | Key value / threshold | Code Reference |
|---|---|---|
| Is the space intended for living/sleeping/eating/cooking? | Yes → habitable; No → not habitable | § R202 |
| Minimum ceiling height for habitable space | 7 feet (2134 mm) (general) | § R313.1 |
| Sloped ceiling exception (habitable rooms) | At least 50% of required floor area ≥ 7 ft; min clear area portion ≥ 5 ft where lower | § R313.1 (exceptions) |
| Natural light required for habitable rooms | Glazed area ≥ 8% of room floor area (unless artificial lighting provided) | § R325.1.1 |
| Natural ventilation required for habitable rooms | Openable area ≥ 4% of room floor area | § R325.1.2 |
(Each of the performance/size/ceiling rules above applies to spaces that meet the definition of habitable space; those rules do not make a non‑habitable space into habitable space.)
How to apply the definition in practice
- First ask: “Is this room intended for living/sleeping/eating/cooking?” If yes, treat it as habitable and apply the habitable‑room rules (ceiling height, light, ventilation). If no, it’s excluded by definition. § R202.
- Second, apply the dimensional/egress/comfort rules that explicitly mention “habitable”: ceiling height (§ R313), light & ventilation (§ R325), etc.
Exceptions & special cases
- Sloped ceilings: a portion of a room with a sloped ceiling may still be habitable if 50% of required floor area meets the minimum height (exceptions in § R313.1).
- Porch/sunroom glazing: required glazed openings for habitable rooms may face into certain roofed porches or sunrooms under the exceptions in § R325.1.1 — this affects how you meet the glazing requirement but does not change whether the room is habitable.
- Mezzanines, sleeping lofts and habitable attics: these elements are regulated separately (e.g., § R314, § R315) and may be habitable only when they meet the specific conditions in those sections; treat the R202 definition as the starting point.
If a provision you need is not present in the files provided here (for example, local amendments or other code parts not in these excerpts), I state that explicitly rather than invent requirements.
Common mistakes
- Counting bathrooms, closets, hallways, garages or utility rooms as habitable space — these are explicitly excluded by § R202.
- Applying habitable‑room minimums (ceiling height, glazing) to non‑habitable spaces — reverse error; exclusions remain non‑habitable even if you add a window.
- Ignoring sloped ceiling exceptions: small portions of low ceiling do not automatically disqualify a room if the 50% rule is met. § R313.1 (exceptions).
- Confusing other definitions (e.g., “living area,” “habitable story” in energy or building code appendices) with the CRC term — always start with § R202 for whether a room is habitable.
Worked example — concrete scenario
Scenario: You convert a 12 ft × 10 ft upstairs room (120 ft²) into a sleeping loft with a sloped ceiling. The ceiling slopes from 8 ft at the peak to 4 ft at the low side.
Step 1 — Is it intended for sleeping? Yes → candidate habitable space under § R202.
Step 2 — Ceiling height check: Required minimum for habitable space is 7 ft. For sloped ceilings the rule allows that at least 50% of the required floor area must have height ≥ 7 ft (see the exception). The room’s floor area = 120 ft², so at least 60 ft² must be ≥ 7 ft high. Measure the plan area where headroom ≥ 7 ft — if that area is ≥ 60 ft², the ceiling rule is met. Reference: § R313.1.
Step 3 — Light & ventilation: If the room is habitable you must provide glazed openings = 8% of 120 ft² = 9.6 ft² of glazing and openable area = 4% of 120 ft² = 4.8 ft² openable. Reference: § R325.1.1 and § R325.1.2.
If any of these criteria are not met (e.g., only 40 ft² of the room reaches 7 ft headroom), you cannot treat the space as habitable without corrective changes.
Related provisions
- § R202 — Definitions (Habitable Space).
- § R313 — Ceiling height requirements for habitable space (minimum 7 ft).
- § R325 — Light, ventilation and heating requirements for habitable rooms (glazing 8%, openable 4%).
- § R314 — Mezzanines (conditions when mezzanines may be habitable).
- § R317 — Garages and carports (non‑habitable uses and special rules for garages).
- § R301 — Building planning and “habitable story” context used elsewhere in code.
Code references
Grounded in the retrieved California Residential Code — click a citation to read the verbatim passage:
CRC § 2016-11 High relevance — show source text
GROSS EXTERIOR WALL AREA is the sum of the window area, door area and exterior wall area.
HABITABLE SPACE is space in a building for living, sleeping, eating or cooking, excluding bathrooms, toilets, hallways, storage areas, closets, utility rooms and similar areas are not considered habitable spaces. (See also “occupiable space”.)
HABITABLE STORY is a story that contains habitable space and that has at least 50 percent of its volume above grade.
HEALTHCARE FACILITY is a health facility as defined in the California Health and Safety Code Division 2, Chapter 2, §1250 or clinic as defined in the California Health and Safety Code Division 2, Chapter 1, Section 1204 that is located within a health facility.
HEAT CAPACITY (HC) is the measurable physical quantity that characterizes the amount of heat required to change a substance’s temperature by a given amount.
HEAT PUMP is an appliance that consists of one or more assemblies; that uses an indoor conditioning coil, a compressor, and a refrigerant-to-outdoor air heat exchanger to provide air heating; and that may also provide air cooling, dehumidifying, humidifying, circulating, or air cleaning.
HEAT PUMP WATER HEATER (HPWH) (See “Water heater.”)
HEATED SLAB FLOOR is a concrete floor either on-grade, raised, or a lightweight concrete slab topping. Heating is provided by a system placed within or under the slab and is sometimes referred to as a radiant slab floor.
HEATING EQUIPMENT is equipment used to provide mechanical heating for a room or rooms in a building.
HEATING SEASONAL PERFORMANCE FACTOR (HSPF) is the total heating output of a central air-conditioning heat pump (in Btu) during its normal use period for heating divided by the total electrical energy input (in watt-hours) during the same period, as determined using the applicable test method in the Appliance Efficiency Regulations.
HEATING SEASONAL PERFORMANCE FACTOR 2 (HSPF2) is the HSPF metric for residential central heat pumps effective January 1, 2023, as created by the U.S. Department of Energy “ISSUANCE 2016-11-30 Energy Conservation Program: Test Procedures for Central Air Conditioners and Heat Pumps, Final Rule.”
HIGH-RISE RESIDENTIAL BUILDING is a building, other than a hotel/motel, of occupancy Group R-2 or R-4 with four or more habitable stories.
HORTICULTURAL LIGHTING consists of luminaires used for plant growth and maintenance. Horticultural luminaires may have either plug-in or hard-wired connections for electric power.
HOTEL/MOTEL is a building or buildings that has six or more guest rooms or a lobby serving six or more guest rooms, where the guest rooms are intended or designed to be used, or which are used, rented or hired out to be occupied, or which are occupied for sleeping purposes by guests, and all conditioned spaces within the same building envelope. Hotel/motel includes all conditioned spaces which are (1) on the same property as the hotel/motel, (2) served by the same central heating, ventilation and air-conditioning system as the hotel/motel, and (3) integrally related to the functioning of the hotel/motel as such, including, but not limited to, exhibition facilities, meeting and conference facilities, food service facilities, lobbies and laundries. Hotel/motel also includes the following:
A building of Occupancy Group R-1,
CRC § 1208.4 High relevance — show source text
An ADU also includes the following: (A) An efficiency unit. (B) A manufactured home, as defined in Section 18007 of the Health and Safety Code. Source: Government Code section 66313, subdivision (a)
Accessory Structure A structure that is accessory and incidental to a dwelling located on the same lot. Source: Government Code section 66313, subdivision (b)
Applicant The person or party responsible for the submittal of an application seeking a permit.
Application A formal request to perform work, which includes all information as required.
Certificate of Occupancy A document issued by local California Building and Safety departments which certifies that a commercial space or newly constructed residential building has been inspected for compliance with the California Building Standards Code and local ordinances which govern construction and occupancy. Source: 2022 California Residential Code section R110
Common Interest Development Any of the following:
(a) A community apartment project. (b) A condominium project. (c) A planned development. (d) A stock cooperative. Source: Civil Code section 4100
Covenants, Conditions, and Restrictions (CC&Rs) A set of rules governing the use of a certain piece of real estate in each community. “Governing documents” includes declarations, bylaws, operating rules, articles of incorporation, or articles of association, which govern the operation of the common interest
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development or association. Source: Civil Code section 4150
Efficiency Dwelling Unit A dwelling unit which contains a minimum of 150 square feet in living space, a separate closet, kitchen sink, cooking appliance, refrigerator, and a separate bathroom containing a water closet, lavatory, bathtub, or shower. Source: Government Code section 66313, subdivision (a)(1); California Building Code section 1208.4
Habitable Space A space in a building for living, sleeping, eating, or cooking. Bathrooms, toilet rooms, closets, halls, storage or utility spaces and similar areas are not considered habitable spaces. Source: 2022 California Building Code section 202
High Quality Transit Corridor A corridor with fixed route bus service with service intervals no longer than 15 minutes during peak commute hours. Source: Public Resources Code section 21155, subdivision (b)
Impact Fee “Impact fee” has the same meaning as the term “fee” as defined in subdivision (b) of Section 66000, and includes the fees specified in Section 66477. “Impact fee” does not include any connection fee or capacity charge charged by a local agency, special district, or water corporation. Source: Government Code section 66324, subdivision (c)(2)
Junior Accessory Dwelling Unit (JADU) A unit that is no more than 500 square feet in size and contained entirely within a singlefamily residence. A JADU may include separate sanitation facilities or may share sanitation facilities with the existing structure. Source: Government Code section 66313, subdivision (d)
Livable Space A space in a dwelling intended for human habitation, including living, sleeping, eating, cooking, or sanitation. Source: Government Code section 66313, subdivision (e)
Living Area The interior habitable area of a dwelling unit, including basements and attics, but does not include a garage or any accessory structure. Source: Government Code section 66313, subdivision (f)
Local Agency A city, county, or city and county, whether general law or chartered. Source: Government Code section 66313, subdivision (g)
CRC § 2.14 High relevance — show source text
GLAZED DOOR is an exterior door having a glazed area of 50 percent or greater of the area of the door.
GLAZING (See “fenestration product.”)
GLOBAL WARMING POTENTIAL (GWP) is the radiative forcing impact of one mass-based unit of a given greenhouse gas relative to an equivalent unit of carbon dioxide over a given period of time.
2025 CALIFORNIA ENERGY CODE 17
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ALL OCCUPANCIES—GENERAL PROVISIONS
GLOBAL WARMING POTENTIAL VALUE (GWP Value) is the 100-year GWP value published by the Intergovernmental Panel on Climate Change (IPCC) in either its Second Assessment Report (SAR) (IPCC, 1995), or its Fourth Assessment A-3 Report (AR4) (IPCC, 2007). Both the 1995 IPCC SAR values and the 2007 IPCC AR4 values are published in Table 2.14 of the 2007 IPCC AR4. The SAR GWP values are found in column “SAR (100-yr)” of Table 2.14.; the AR4 GWP values are found in column “100 yr” of Table 2.14.
GOVERNMENTAL AGENCY is any public agency or subdivision thereof, including, but not limited to, any agency of the state, a county, a city, a district, an association of governments or a joint power agency.
GROSS EXTERIOR ROOF AREA is the sum of the skylight area and the exterior roof/ceiling area.
GROSS EXTERIOR WALL AREA is the sum of the window area, door area and exterior wall area.
HABITABLE SPACE is space in a building for living, sleeping, eating or cooking, excluding bathrooms, toilets, hallways, storage areas, closets, utility rooms and similar areas are not considered habitable spaces. (See also “occupiable space”.)
HABITABLE STORY is a story that contains habitable space and that has at least 50 percent of its volume above grade.
HEALTHCARE FACILITY is a health facility as defined in the California Health and Safety Code Division 2, Chapter 2, §1250 or clinic as defined in the California Health and Safety Code Division 2, Chapter 1, Section 1204 that is located within a health facility.
HEAT CAPACITY (HC) is the measurable physical quantity that characterizes the amount of heat required to change a substance’s temperature by a given amount.
HEAT PUMP is an appliance that consists of one or more assemblies; that uses an indoor conditioning coil, a compressor, and a refrigerant-to-outdoor air heat exchanger to provide air heating; and that may also provide air cooling, dehumidifying, humidifying, circulating, or air cleaning.
HEAT PUMP WATER HEATER (HPWH) (See “Water heater.”)
HEATED SLAB FLOOR is a concrete floor either on-grade, raised, or a lightweight concrete slab topping. Heating is provided by a system placed within or under the slab and is sometimes referred to as a radiant slab floor.
HEATING EQUIPMENT is equipment used to provide mechanical heating for a room or rooms in a building.
CRC § 1.1 High relevance — show source text
SECTION R313—CEILING HEIGHT
R313.1 Minimum height. Habitable space, hallways and portions of basements containing these spaces shall have a ceiling height of not less than 7 feet (2134 mm). Bathrooms, toilet rooms and laundry rooms shall have a ceiling height of not less than 6 feet 8 inches (2032 mm).
Exceptions:
- For rooms with sloped ceilings, the required floor area of the room shall have a ceiling height of not less than 5 feet (1524 mm) and not less than 50 percent of the required floor area shall have a ceiling height of not less than 7 feet (2134 mm).
- The ceiling height above bathroom and toilet room fixtures shall be such that the fixture is capable of being used for its intended purpose. A shower or tub equipped with a showerhead shall have a ceiling height of not less than 6 feet 8 inches (2032 mm) above an area of not less than 30 inches (762 mm) by 30 inches (762 mm) at the showerhead.
- Beams, girders, ducts or other obstructions in basements containing habitable space shall be permitted to project to within 6 feet 4 inches (1931 mm) of the finished floor.
- Beams and girders spaced apart not less than 36 inches (914 mm) in clear finished width shall project not more than 78 inches (1981 mm) from the finished floor.
R313.1.1 Basements. Portions of basements that do not contain habitable space or hallways shall have a ceiling height of not less than 6 feet 8 inches (2032 mm).
Exception: At beams, girders, ducts or other obstructions, the ceiling height shall be not less than 6 feet 4 inches (1931 mm) from the finished floor.
2025 CALIFORNIA RESIDENTIAL CODE 3-59
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BUILDING PLANNING
R313.1.2 Habitable attics and basements in existing buildings. Where a habitable attic or habitable space in a basement is created in an existing building, ceiling height shall not be less than 6 feet 8 inches (2032 mm). Bathrooms, toilet rooms and laundry rooms shall have a ceiling height of not less than 6 feet 4 inches (1930 mm).
Exceptions:
- For rooms with sloped ceilings, the required floor area of the room shall have a ceiling height of not less than 5 feet (1524 mm) and not less than 50 percent of the required floor area shall have a ceiling height of not less than 6 feet 8 inches (2032 mm).
- At beams, girders, ducts or other obstructions, the ceiling height shall be not less than 6 feet 4 inches (1930 mm) from the finished floor.
SECTION R314—MEZZANINES
R314.1 General. Mezzanines shall comply with Sections R314.2 through R314.5.
Exception: Sleeping lofts in dwelling units and sleeping units shall be permitted to comply with Section R315, subject to the limitations in Section R315.2.
R314.2 Mezzanines. The clear height above and below mezzanine floor construction shall be not less than 7 feet (2134 mm).
CRC § 1.2. Medium relevance — show source text
Not greater than one-third of the floor area of the story below. 1.2. Not greater than one-half of the floor area of the story below where the habitable attic is located within a dwelling unit equipped with an automatic sprinkler system in accordance with Section R309 . 2. The occupiable space is enclosed by the roof assembly above, knee walls, if applicable, on the sides and the floor-ceiling assembly below. 3. The floor of the habitable attic does not extend beyond the exterior walls of the story below. 4. Where a habitable attic is located above a third story, an automatic sprinkler system in accordance with Section R309 shall be installed in the habitable attic and remaining portion of the townhouse unit or dwelling unit or units located beneath the habitable attic.
R316.4 Means of egress. The means of egress for habitable attics shall comply with the applicable provisions of Section R318.
SECTION R317—GARAGES AND CARPORTS
R317.1 Floor surface. Garage floor surfaces shall be of approved noncombustible material.
The area of floor used for parking of automobiles or other vehicles shall be sloped to facilitate the movement of liquids to a drain or toward the main vehicle entry doorway.
R317.2 Carports. Carports shall be open on not less than two sides. Carport floor surfaces shall be of approved noncombustible material. Carports not open on two or more sides shall be considered to be a garage and shall comply with the provisions of this section for garages.
The area of floor used for parking of automobiles or other vehicles shall be sloped to facilitate the movement of liquids to a drain or toward the main vehicle entry doorway.
Exception: Asphalt surfaces shall be permitted at ground level in carports.
R317.3 Flood hazard areas. Garages and carports located in flood hazard areas as established by Table R301.2 shall be constructed in accordance with Section R306.
R317.4 Automatic garage door openers. Automatic garage door openers, if provided, shall be listed and labeled in accordance with UL 325 and shall be installed in accordance with the manufacturer’s installation instructions. See Health and Safety Code Sections 19890, 19891 and 19892 for additional provisions for residential garage door openers.
R317.5 Fire sprinklers location on property . Private garages shall be protected by fire sprinklers where the garage wall has been designed based on Table R302.1(2), Note a. Sprinklers in garages shall be connected to an automatic sprinkler system that complies with Section R309 . Garage sprinklers shall be residential sprinklers or quick-response sprinklers, designed to provide a density of 0.05 gpm/ft [2] . Garage doors shall not be considered obstructions with respect to sprinkler placement.
2025 CALIFORNIA RESIDENTIAL CODE 3-61
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BUILDING PLANNING
CRC § 2022-1.0 Medium relevance — show source text
GROUND LEVEL PLAY COMPONENT. [DSA-AC] A play component that is approached and exited at the ground level.
[BS] GROUND SNOW LOAD, p g . Design ground snow loads.
[BS] GROUND SNOW LOAD, p g(asd) . Allowable stress design ground snow loads
[BS] GROUND SNOW LOAD GEODATABASE. The ASCE database (version 2022-1.0) of geocoded values of risk-targeted design ground snow load values.
[BG] GROUP HOME. Group Home means a facility which provides 24-hour care and supervision to children, provides services specified in this chapter to a specific client group, and maintains a structured environment, with such services provided at least in part by staff employed by the licensee. The care and supervision provided by a group home shall be nonmedical except as permitted by Welfare and Institutions Code Section 17736(b). Since small family and foster family homes, by definition, care for six or fewer children only, any facility providing 24-hour care for seven or more children must be licensed as a group home.
[BE] GUARD [DSA-AC, HCD 1, HCD 2 & HCD 1-AC] OR GUARDRAIL . A building component or a system of building components located at or near the open sides of elevated walking surfaces that minimizes the possibility of a fall from the walking surface to a lower level.
[BG] GUESTROOM. A room used or intended to be used by one or more guests for living or sleeping purposes.
[BS] GYPSUM BOARD. A type of gypsum panel product consisting of a noncombustible core primarily of gypsum with paper surfacing.
[BS] GYPSUM PANEL PRODUCT. The general name for a family of sheet products consisting essentially of gypsum complying with the standards specified in Table 2506.2, Table 2507.2 and Chapter 35.
[BS] GYPSUM PLASTER. A mixture of calcined gypsum or calcined gypsum and lime and aggregate and other approved materials as specified in this code.
[BS] GYPSUM SHEATHING. Gypsum panel products specifically manufactured with enhanced water resistance for use as a substrate for exterior surface materials.
[BS] GYPSUM VENEER PLASTER. Gypsum plaster applied to an approved base in one or more coats normally not exceeding [1] / 4 inch (6.4 mm) in total thickness.
[BS] GYPSUM WALLBOARD. A gypsum board used primarily as an interior surfacing for building structures.
[BG] HABITABLE SPACE. A space in a building for living, sleeping, eating or cooking. Bathrooms, toilet rooms, closets, halls, storage or utility spaces and similar areas are not considered habitable spaces.
HALL CALL CONSOLE. [DSA-AC] An elevator call user interface exclusive to a destination-oriented elevator system that requires the user to select a destination floor prior to entering the elevator car.
[F] HALOGENATED EXTINGUISHING SYSTEM. A fire-extinguishing system using one or more atoms of an element from the halogen chemical series: fluorine, chlorine, bromine and iodine.
[F] HANDLING. The deliberate transport by any means to a point of storage or use .
2025 CALIFORNIA BUILDING CODE 2-35
CRC § 2-14 Medium relevance — show source text
[MP] GRAYWATER. Waste discharged from lavatories, bathtubs, showers, clothes washers and laundry trays.
[MP] GRIDDED WATER DISTRIBUTION SYSTEM. A water distribution system where every water distribution pipe is interconnected so as to provide two or more paths to each fixture supply pipe.
[RB] GROSS AREA OF EXTERIOR WALLS. The normal projection of all exterior walls, including the area of all windows and doors installed therein.
[MP] GROUND-SOURCE HEAT PUMP LOOP SYSTEM. Piping buried in horizontal or vertical excavations or placed in a body of water for the purpose of transporting heat transfer liquid to and from a heat pump. Included in this definition are closed loop systems in which the liquid is recirculated and open loop systems in which the liquid is drawn from a well or other source.
[RB] GUARD OR GUARDRAIL . A building component or a system of building components located near the open sides of elevated walking surfaces that minimizes the possibility of a fall from the walking surface to the lower level.
[RB] GUESTROOM. Any room or rooms used or intended to be used by one or more guests for living or sleeping purposes.
[RB] GYPSUM BOARD. A type of gypsum panel product consisting of a noncombustible core primarily of gypsum with paper surfacing.
[RB] GYPSUM PANEL PRODUCT. The general name for a family of sheet products consisting essentially of gypsum complying with the standards specified in Section R702.3 and Chapter 44 of this code.
[RB] GYPSUM SHEATHING. Gypsum panel products specifically manufactured with enhanced water resistance for use as a substrate for exterior surface materials.
[RB] GYPSUM WALLBOARD. A gypsum board used primarily as interior surfacing for building structures.
[RB] HABITABLE SPACE. A space in a building for living, sleeping, eating or cooking. Bathrooms, toilet rooms, closets, halls, storage or utility spaces and similar areas are not considered habitable spaces.
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DEFINITIONS
[RB] HANDRAIL. A horizontal or sloping rail intended for grasping by the hand for guidance or support.
[MP] HANGERS. See “Supports.”
[MP] HAZARDOUS LOCATION. Any location considered to be a fire hazard for flammable vapors, dust, combustible fibers or other highly combustible substances.
[MP] HEAT PUMP. A refrigeration system or factory-made appliance that utilizes refrigerant to transfer heat into a space or substance.
[RB] HEIGHT, BUILDING. The vertical distance from grade plane to the average height of the highest roof surface.
[RB] HEIGHT, STORY. The vertical distance from top to top of two successive tiers of beams or finished floor surfaces; and, for the topmost story, from the top of the floor finish to the top of the ceiling joists or, where there is not a ceiling, to the top of the roof rafters.
[MP] HIGH-TEMPERATURE (H.T.) CHIMNEY. A high-temperature chimney complying with the requirements of UL 103. A Type H.T. chimney is identifiable by the markings “Type H.T.” on each chimney pipe section.
California Residential Code Medium relevance — show source text
GAS ROOM, HYDROGEN FUEL. See “Hydrogen fuel gas room.”
GASEOUS HYDROGEN SYSTEM. An assembly of piping, devices and apparatus designed to generate, store, contain, distribute or transport a nontoxic, gaseous hydrogen-containing mixture having not less than 95-percent hydrogen gas by volume and not more than 1-percent oxygen by volume. Gaseous hydrogen systems consist of items such as compressed gas containers, reactors and appurtenances, including pressure regulators, pressure relief devices, manifolds, pumps, compressors and interconnecting piping and tubing and controls.
GLOVE BOX. A sealed enclosure in which items inside the box are handled exclusively using long gloves sealed to ports in the enclosure.
[BE] GRADE FLOOR EMERGENCY ESCAPE AND RESCUE OPENING. An emergency escape and rescue opening located such that the bottom of the clear opening is not more than 44 inches (1118 mm) above or below the finished ground level adjacent to the opening.
[BG] GRADE PLANE. A reference plane representing the average of finished ground level adjoining the building at exterior walls. Where the finished ground level slopes away from the exterior walls, the reference plane shall be established by the lowest points within the area between the building and the lot line or, where the lot line is more than 6 feet (1829 mm) from the building, between the building and a point 6 feet (1829 mm) from the building.
[BE] GRANDSTAND. Tiered seating supported on a dedicated structural system and two or more rows high and is not a building element (see “Bleachers”).
[BG] GROUP HOME. Group Home means a facility which provides 24-hour care and supervision to children, provides services specified in this chapter to a specific client group, and maintains a structured environment, with such services provided at least in part by staff employed by the licensee. The care and supervision provided by a group home shall be nonmedical except as permitted by Welfare and Institutions Code Section 17736(b). Since small family and foster family homes, by definition, care for six or fewer children only, any facility providing 24-hour care for seven or more children must be licensed as a group home.
[BE] GUARD. A building component or a system of building components located at or near the open sides of elevated walking surfaces that minimizes the possibility of a fall from the walking surface to a lower level.
[BG] GUESTROOM. A room used or intended to be used by one or more guests for living or sleeping purposes.
[BS] GYPSUM BOARD. A type of gypsum panel product consisting of a noncombustible core primarily of gypsum with paper surfacing.
[BS] GYPSUM WALLBOARD. A gypsum board used primarily as an interior surfacing for building structures.
[BG] HABITABLE SPACE. A space in a building for living, sleeping, eating or cooking. Bathrooms, toilet rooms, closets, halls, storage or utility spaces and similar areas are not considered habitable spaces.
HALOGENATED EXTINGUISHING SYSTEM. A fire-extinguishing system using one or more atoms of an element from the halogen chemical series: fluorine, chlorine, bromine and iodine.
HANDLING. The deliberate transport by any means to a point of storage or use.
[BE] HANDRAIL. A horizontal or sloping rail intended for grasping by the hand for guidance or support.
CRC § 2506.2 Medium relevance — show source text
[BS] GYPSUM PANEL PRODUCT. The general name for a family of sheet products consisting essentially of gypsum complying with the standards specified in Table 2506.2, Table 2507.2 and Chapter 35.
[BS] GYPSUM PLASTER. A mixture of calcined gypsum or calcined gypsum and lime and aggregate and other approved materials as specified in this code.
[BS] GYPSUM SHEATHING. Gypsum panel products specifically manufactured with enhanced water resistance for use as a substrate for exterior surface materials.
[BS] GYPSUM VENEER PLASTER. Gypsum plaster applied to an approved base in one or more coats normally not exceeding [1] / 4 inch (6.4 mm) in total thickness.
[BS] GYPSUM WALLBOARD. A gypsum board used primarily as an interior surfacing for building structures.
[BG] HABITABLE SPACE. A space in a building for living, sleeping, eating or cooking. Bathrooms, toilet rooms, closets, halls, storage or utility spaces and similar areas are not considered habitable spaces.
HALL CALL CONSOLE. [DSA-AC] An elevator call user interface exclusive to a destination-oriented elevator system that requires the user to select a destination floor prior to entering the elevator car.
[F] HALOGENATED EXTINGUISHING SYSTEM. A fire-extinguishing system using one or more atoms of an element from the halogen chemical series: fluorine, chlorine, bromine and iodine.
[F] HANDLING. The deliberate transport by any means to a point of storage or use .
2025 CALIFORNIA BUILDING CODE 2-35
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DEFINITIONS
[BE] HANDRAIL. A horizontal or sloping rail intended for grasping by the hand for guidance or support.
HANDWASHING FIXTURE. Refer to the California Plumbing Code, Section 210.0.
HANDWASHING FIXTURE. [OSHPD 1, 2, 3, 4 & 5] A lavatory provided in patient rooms, nurse stations and other patient care areas intended for staff hygiene and infection control. These special-use lavatories are an element of a handwashing station as defined in Section 1224.3. Refer to the California Plumbing Code Section 210.0 definition for additional requirements associated with handwashing fixtures.
[BS] HARDBOARD. A fibrous-felted, homogeneous panel made from lignocellulosic fibers consolidated under heat and pressure in a hot press to a density not less than 31 pcf (497 kg/m [3] ).
HARDWARE. See “Fire exit hardware” and “Panic hardware.”
[F] HAZARDOUS MATERIALS. Those chemicals or substances that are physical hazards or health hazards as classified in Section 307 and the California Fire Code, whether the materials are in usable or waste condition.
[F] HAZARDOUS PRODUCTION MATERIAL (HPM). A solid, liquid or gas associated with semiconductor manufacturing that has a degree-of-hazard rating in health, flammability or instability of Class 3 or 4 as ranked by the California Electrical Code and which is used directly in research, laboratory or production processes which have as their end product materials that are not hazardous.
CRC § 2-23 Medium relevance — show source text
[BE] GUARD. A building component or a system of building components located at or near the open sides of elevated walking surfaces that minimizes the possibility of a fall from the walking surface to a lower level.
[BG] GUESTROOM. A room used or intended to be used by one or more guests for living or sleeping purposes.
[BS] GYPSUM BOARD. A type of gypsum panel product consisting of a noncombustible core primarily of gypsum with paper surfacing.
[BS] GYPSUM WALLBOARD. A gypsum board used primarily as an interior surfacing for building structures.
[BG] HABITABLE SPACE. A space in a building for living, sleeping, eating or cooking. Bathrooms, toilet rooms, closets, halls, storage or utility spaces and similar areas are not considered habitable spaces.
HALOGENATED EXTINGUISHING SYSTEM. A fire-extinguishing system using one or more atoms of an element from the halogen chemical series: fluorine, chlorine, bromine and iodine.
HANDLING. The deliberate transport by any means to a point of storage or use.
[BE] HANDRAIL. A horizontal or sloping rail intended for grasping by the hand for guidance or support.
HAZARDOUS MATERIALS. Those chemicals or substances which are physical hazards or health hazards as defined and classified in this chapter, whether the materials are in usable or waste condition.
HAZARDOUS PRODUCTION MATERIAL (HPM). A solid, liquid or gas associated with semiconductor manufacturing that has a degreeof-hazard rating in health, flammability or instability of Class 3 or 4 as ranked by NFPA 704 and which is used directly in research, laboratory or production processes which have, as their end product, materials that are not hazardous.
HEALTH HAZARD. A classification of a chemical for which there is statistically significant evidence that acute or chronic health effects are capable of occurring in exposed persons. The term “health hazard” includes chemicals that are toxic, highly toxic and corrosive.
HEAT DETECTOR. See “Detector, heat.”
[BG] HEIGHT, BUILDING. The vertical distance from grade plane to the average height of the highest roof surface.
HELIPORT. An area of land or water or a structural surface that is used, or intended for use, for the landing and taking off of helicopters, and any appurtenant areas which are used, or intended for use, for heliport buildings and other heliport facilities.
HELISTOP. The same as “Heliport,” except that fueling, defueling, maintenance, repairs or storage of helicopters is not permitted.
HI-BOY. A cart used to transport hot roofing materials on a roof.
2025 CALIFORNIA FIRE CODE 2-23
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
DEFINITIONS
HIGHER EDUCATION LABORATORY. Laboratories in Group B occupancies used for educational purposes above the 12th grade. Storage, use and handling of chemicals in such laboratories shall be limited to purposes related to testing, analysis, teaching, research or developmental activities on a nonproduction basis.
HIGHLY TOXIC. A material which produces a lethal dose or lethal concentration which falls within any of the following categories: 1.
CRC § 6.9 Medium relevance — show source text
R324.6.9 Testing and labeling. Unit skylights and tubular daylighting devices shall be tested by an approved independent laboratory, and bear a label identifying manufacturer, performance grade rating and approved inspection agency to indicate compliance with the requirements of AAMA/WDMA/CSA 101/I.S.2/A440.
2025 CALIFORNIA RESIDENTIAL CODE 3-71
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
BUILDING PLANNING
R324.6.9.1 Comparative analysis for glass-glazed unit skylights. Structural wind load design pressures for glass-glazed unit skylights different than the size tested in accordance with Section R324.6.9 shall be permitted to be different than the design value of the tested unit where determined in accordance with one of the following comparative analysis methods:
Structural wind load design pressures for glass-glazed unit skylights smaller than the size tested in accordance with Section R324.6.9 shall be permitted to be higher than the design value of the tested unit provided that such higher pressures are determined by accepted engineering analysis. Components of the smaller unit shall be the same as those of the tested unit. Such calculated design pressures shall be validated by an additional test of the glass-glazed unit skylight having the highest allowable design pressure.
In accordance with WDMA I.S.11.
SECTION R325—LIGHT, VENTILATION AND HEATING
R325.1 Habitable rooms. Habitable space shall be provided natural light and natural ventilation in accordance with Sections R325.1.1 through R325.1.3.
R325.1.1 Natural light. Habitable rooms shall have an aggregate area of glazed openings not less than 8 percent of the floor area of such rooms. Required glazed openings shall face directly onto a street, alley or public way, or a yard or court located on the same lot as the building.
Exceptions:
Required glazed openings shall be permitted to face into a roofed porch, deck or patio adjacent to a street, alley, public way, yard or court, where there the longer side of the roofed area is not less than 65 percent unobstructed and the ceiling height is not less than 7 feet (2134 mm).
Required glazed openings shall be permitted to face into a sunroom adjacent to a street, alley, public way, yard or court.
Glazed openings are not required where artificial light is provided that is capable of producing an average illumination of 6 footcandles (65 lux) over the area of the room at a height of 30 inches (762 mm) above the floor level.
Eave projections shall not be considered as obstructing the clear open space of a yard or court. 5. Glazed openings may open into a passive solar energy collector provided the area of exterior glazed opening(s) into the passive solar energy collector is increased to compensate for the area required by the interior space.
R325.1.2 Natural ventilation. Habitable rooms shall have an aggregate area openable to the outdoors not less than 4 percent of the floor area of such rooms. Openings shall be through windows, skylights, doors, louvers or other approved openings to the outdoor air. Such openings shall be provided with ready access or shall otherwise be readily controllable by the building occupants.
Exceptions:
CRC § 1206.4 Medium relevance — show source text
Exception: Impact sound insulation is not required for floor-ceiling assemblies over nonhabitable rooms or spaces not designed to be occupied, such as garages, mechanical rooms or storage areas.
1206.4 Allowable interior noise levels. Interior noise levels attributable to exterior sources shall not exceed 45 dB in any habitable room. The noise metric shall be either the day-night average sound level (Ldn) or the community noise equivalent level (CNEL), consis- tent with the noise element of the local general plan.
1206.5 Acoustical control. [BSC-CG] See California Green Building Standards Code, Chapter 5, Division 5.5 for additional sound trans- mission requirements.
SECTION 1207—ENHANCED CLASSROOM ACOUSTICS
1207.1 General. Enhanced classroom acoustics, where required by this section, shall comply with Section 808 of ICC A117.1.
1207.2 Where required. In Group E occupancies, enhanced classroom acoustics shall be provided in all classrooms with a volume of 20,000 cubic feet (566 m [3] ) or less.
SECTION 1208—INTERIOR SPACE DIMENSIONS
1208.1 Minimum room widths. Habitable spaces, other than a kitchen, shall be not less than 7 feet (2134 mm) in any plan dimension. Kitchens shall have a clear passageway of not less than 3 feet (914 mm) between counter fronts and appliances or counter fronts and walls.
[HCD 1] For limited-density owner-built rural dwellings, there shall be no requirements for room dimensions, provided there is adequate light and ventilation and adequate means of egress.
1208.2 Minimum ceiling heights. Occupiable spaces, habitable spaces and corridors shall have a ceiling height of not less than 7 feet 6 inches (2286 mm) above the finished floor. Bathrooms, toilet rooms, kitchens, storage rooms and laundry rooms shall have a ceiling height of not less than 7 feet (2134 mm) above the finished floor.
Exceptions:
- In one- and two-family dwellings, beams or girders spaced not less than 4 feet (1219 mm) on center shall be permitted to project not more than 6 inches (152 mm) below the required ceiling height.
- If any room in a building has a sloped ceiling, the prescribed ceiling height for the room is required in one-half the area thereof. Any portion of the room measuring less than 5 feet (1524 mm) from the finished floor to the ceiling shall not be included in any computation of the minimum area thereof.
- The height of mezzanines and spaces below mezzanines shall be in accordance with Section 505.2.
12-8 2025 CALIFORNIA BUILDING CODE
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
INTERIOR ENVIRONMENT
- Corridors contained within a dwelling unit or sleeping unit in a Group R occupancy shall have a ceiling height of not less than 7 feet (2134 mm) above the finished floor.
5. [OSHPD 1, 2, 3 & 5] Minimum ceiling heights shall comply with Section 1224.4.10. 6. [OSHPD 4] Minimum ceiling heights shall comply with Section 1227.8.
Frequently asked questions
Can I convert a garage into habitable space and count it as floor area?
Yes — a garage converted to living/sleeping/eating/cooking may become habitable, but it must meet the habitable‑room rules (definition per § R202 and then ceiling, light/ventilation, fire and other requirements in the applicable sections). Garage specifics are in § R317.
Is a kitchen always habitable?
Yes. Cooking is one of the listed habitable uses in § R202, so a kitchen counts as habitable space and must meet the applicable habitable‑room requirements.
Do closets or storage rooms ever count as habitable?
No. Closets, storage or utility spaces are explicitly excluded from habitable space in § R202. If you intend a space for living/sleeping/eating/cooking, redesignate and bring it into compliance with the habitable‑room requirements.
How much window area does a habitable room need?
A habitable room normally requires glazed openings equal to at least 8% of the floor area (§ R325.1.1) and openable area of at least 4% for natural ventilation (§ R325.1.2). Exceptions for artificial light or certain porch/sunroom situations are listed in the same section.
If a loft has low headroom near the edges, can it still be habitable?
Possibly — sloped ceiling exceptions allow that 50% of the required floor area must be ≥ 7 ft (see § R313.1 exceptions). You must confirm the plan area meeting the 7‑ft height equals at least half of the required floor area.
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