ICC R5 key terms

The code chapter that establishes which buildings and structures the residential code governs, who enforces it, what permits and inspections are required, and how violations and appeals are handled.

A written authorization issued by the building official that allows construction, alteration, or demolition work to begin and that requires inspections at defined stages before the work may be covered or occupied.

A panel appointed to hear challenges to decisions of the building official, including interpretations of code text, but generally not empowered to waive requirements that are clear and specific.

A grant of relief from a specific code requirement where strict application causes practical difficulty, decided case by case and subject to conditions that protect the intent of the code.

A provision allowing products, designs, or construction methods not specifically named in the code when the building official finds them equivalent in quality, strength, fire resistance, and safety to the prescribed approach.

Accepted by the building official as meeting the code, either because the item is listed by a recognized testing agency or because it is otherwise shown by test, research, or accepted practice to comply.

Placement of a product on a published register maintained by an approved testing agency that maintains periodic inspection of production and identifies the product as meeting a designated standard.

A document issued after final inspection confirming that the completed work complies with the permitted plans and code, allowing the building or portion of it to be lawfully used or occupied.

An official who performs the required stage inspections, such as foundation, framing, and final, and whose approval must be obtained before work is concealed or the structure is occupied.

The vertical dimension measured from the grade plane to the average height of the highest roof surface, used to set limits based on construction type and fire protection.

A reference horizontal plane derived from the average of the finished ground elevations at the exterior walls, used to measure building height and number of stories above grade.

The total area within the exterior walls of a building at each floor level, used with height and construction type to determine allowable size and required fire protection.

The maximum floor area permitted for a given occupancy and construction type, increased when the building is equipped with an automatic sprinkler system or separated by fire walls.

Categories that describe how much of a building's structural elements are noncombustible and protected, ranging from the most fire-resistive to combustible wood framing.

The period of time, in hours or minutes, that a building element resists a standard fire test while continuing to carry its load or block passage of flame and heat.

The distance measured from the exterior wall of a building to the nearest lot line or other building on the same lot, used to set limits on openings and required fire resistance.

Requirements that habitable rooms receive natural or artificial light and ventilation through windows, doors, or mechanical systems sized to the room's floor area.

A space used for living, sleeping, eating, or cooking, excluding bathrooms, closets, halls, and similar spaces, and therefore subject to minimum area, ceiling height, light, and ventilation rules.

The minimum clear vertical dimension required for habitable rooms and other spaces, measured from finished floor to finished ceiling, with allowances for sloped ceilings and beams.

The structural system that transfers building loads to the ground, including footings, slabs, piles, and walls, and which must extend below the frost line where frost heave is a concern.

The widened base of a foundation wall or column that spreads loads over a large enough soil area to keep bearing pressure within the soil's allowable capacity.

The depth to which soil is expected to freeze in winter; footings must be placed below it, or otherwise protected, so that frost movement does not lift or crack the foundation.

Measures that keep water away from below-grade spaces, including footing drains, waterproofing or dampproofing of foundation walls, and grading that slopes soil away from the building.

The system of joists, beams, and subfloor that carries floor loads, sized by span tables and limited in deflection, notching, and boring to preserve structural capacity.

The assembly of studs, plates, and sheathing that supports vertical and lateral loads, with stud size, spacing, and bracing governed by tabulated allowances and height limits.

The rafters, trusses, ridge, and sheathing that form the roof structure, designed for dead, live, and snow loads and connected to resist uplift and lateral forces.

A line of wall segments designed to resist lateral loads from wind and earthquakes, requiring specified bracing methods, lengths, and spacing depending on the seismic or wind exposure.

A horizontal structural member spanning over an opening in a wall to carry the loads above it to adjacent framing, sized according to the span and the load it supports.

Rules limiting cuts through framing members so that remaining material can still carry design loads, with stricter limits near supports and for certain member depths.

Panels fastened to rafters or trusses that transfer loads, provide a nailing base for roofing, and act as a diaphragm to resist lateral forces when properly attached.

Demonstrating that a dwelling meets efficiency requirements for the building envelope, mechanical systems, and lighting, typically through a prescriptive package of measures or a performance calculation.

The boundary separating conditioned interior space from unconditioned or exterior space, including insulation, windows, doors, and air sealing that control heat flow.

A measure of how quickly heat passes through an assembly such as a window or wall; lower values mean better insulation, and code sets maximum values by climate zone.

A measure of a material's resistance to heat flow; higher values mean better insulating performance, and required values vary with the building component and climate zone.

Closing joints and penetrations in air distribution systems so conditioned air reaches its intended space, required in specified locations and verified by testing in some cases.

A continuous and unobstructed path from any point in a building to a public way, made up of the exit access, the exit, and the exit discharge.

The portion of the means of egress that leads from an occupied space to an exit, including aisles, corridors, and the travel distance measured along that path.

The clear width of a means of egress component, sized by the number of occupants it serves and subject to minimum dimensions for doors, corridors, and stairs.

The number of people calculated for a space by applying a floor-area factor to its use, used to size exits, corridors, and stairs along the egress path.

A device that detects smoke and sounds a local warning, required in sleeping rooms and adjacent areas and wired so that interconnected units sound together in new construction.

Construction such as walls, ceilings, or door assemblies with a rated resistance that slows fire spread between dwelling units, garages, and other areas for a specified time.

An operable window or door in each sleeping room that provides a clear opening to the outside, with minimum area, height, and sill limits, allowing escape from a fire.