ICC B3 key terms

Written authorization from the code official allowing construction, alteration, or demolition to begin after the submitted documents have been reviewed and found to comply with applicable code requirements.

The code official's examination of construction documents before a permit is issued, checking occupancy, egress, fire protection, structural, and energy provisions for compliance with the adopted code.

A document issued after final inspection confirming that a building or portion complies with the approved plans and code, permitting the stated occupancy to be legally established and used.

A panel appointed by the jurisdiction to hear appeals of code official decisions, interpretations, and requests for modification, with authority to grant relief consistent with the code's intent.

A formal exception granted by the code official when strict application of a code provision causes practical difficulty, provided the alternative solution offers equivalent or greater safety, health, and welfare.

A code allowance for materials, designs, or methods of construction not specifically prescribed, when the code official finds them equivalent in quality, strength, effectiveness, fire resistance, durability, and safety.

Technical documents published by outside organizations, such as ASTM, NFPA, ASCE, or ACI, that the code adopts by reference and that carry the same legal force as the code text.

A change in how a building or space is occupied that moves it into a different occupancy group or subgroup, potentially triggering new requirements for egress, fire protection, and accessibility.

The grouping of a building or space by its type of use-assembly, business, mercantile, residential, storage, factory, and similar-which establishes baseline requirements for egress, fire protection, and construction.

A category from Type I through Type V, with A and B subtypes, describing how much fire resistance the structural frame and building elements provide; more resistive types permit taller and larger buildings.

The maximum floor area permitted on a story for a given construction type and occupancy, adjusted for open frontage, sprinkler protection, and separations, and used with height limits to control building size.

The maximum number of stories and the maximum overall height allowed for a building, determined by its construction type, occupancy group, and fire protection features such as automatic sprinklers.

The time in hours or minutes that a building element withstands a standardized fire test while continuing to serve its structural or separating function, as established by an approved test standard.

The total floor area enclosed by fire walls, fire barriers, exterior walls, or horizontal assemblies, used to limit building size and to set thresholds for sprinklers and other protection.

A fire-resistance-rated wall with enough structural stability to remain standing when fire attacks from either side, used to create separate buildings and permit unlimited area or mixed construction types.

A fire-resistance-rated wall or horizontal assembly that limits fire spread, used to separate occupancies, protect exit enclosures, or enclose hazardous areas, and must be continuous and supported by rated construction.

A vertical assembly with a lower fire-resistance rating than a fire barrier, commonly used to separate dwelling units, guest rooms, or corridors from other spaces within the same occupancy.

A continuous assembly designed to restrict the movement of smoke, fitted with smoke-resistant doors and often used with smoke control, typically protecting areas of refuge and sleeping occupancies.

A rating of Class A, B, or C given to wall and ceiling finishes based on flame spread and smoke-developed indexes from standardized tests, limiting how quickly finishes spread fire and smoke.

The total number of people a space is designed to hold, calculated from floor area and use-based factors, which establishes required egress width, the number of exits, and plumbing fixture counts.

A continuous and unobstructed route from any point inside a building to a public way, consisting of exit access, the exit, and exit discharge.

The distance measured along the natural path from the most remote point in a space to the nearest exit, limited by occupancy group and whether the building is sprinklered.

The part of exit access travel where occupants have only one route before reaching a point with a choice of two directions, limited in length to prevent excessive single-direction travel.

The portion of the means of egress between the end of an exit and the public way, including lobbies, courtyards, and exterior walkways, which must stay unobstructed and often fire-separated.

A passage through or around a fire-resistance-rated wall that lets occupants move into a safe area elsewhere in the same building, and that can be counted as an exit for egress capacity.

A protected space where people unable to use stairs can wait for assistance, usually separated by smoke barriers and provided with an accessible route and two-way communication.

A continuous, unobstructed path connecting accessible spaces and elements, meeting limits on width, slope, surface, and changes in level so people with disabilities can travel independently.

An egress route designed for use by people with disabilities, requiring an accessible route, areas of refuge or accessible exits, and features such as widened landings or platform lifts.

The variable load produced by occupancy and use, including people, furniture, vehicles, and stored goods, usually expressed in pounds per square foot for each occupancy.

The permanent weight of the building itself, including structure, walls, floors, roofs, and fixed equipment, which acts continuously and must be carried by the structural system.

A classification from A through F assigned from the site's seismic hazard and the building's occupancy and seismic use group, which determines the seismic detailing and bracing required.

The force wind exerts on a structure, calculated from basic wind speed, exposure category, height, and building shape, and used to design framing and cladding for lateral resistance.

A sheet or coating installed behind exterior cladding that drains water which penetrates the cladding, protecting sheathing and framing from moisture damage while still allowing vapor to escape.

Thin, water-resistant material installed at joints, penetrations, and edges such as roofs, walls, and windows to direct water away from concealed spaces and prevent leakage into the building.

The outer layer of a roof assembly that sheds rain and snow, whose class rating indicates resistance to fire originating outside the building.

The boundary separating conditioned interior space from unconditioned or outdoor space, formed by insulation, windows, doors, and roof and wall assemblies that control heat transfer.

A piped system with heat-activated heads that discharge water onto a fire automatically to control or extinguish it; its presence often relaxes other requirements such as area and height limits.

A connected set of detectors, manual pull stations, notification appliances, and a control panel that detects fire conditions and warns occupants, and may also control smoke and elevators.

An engineered arrangement of fans, dampers, and barriers that limits smoke movement or removes smoke from a space to protect means of egress and assist firefighting.