OBC House Exam key terms

The grouping of a building or portion of it by the type of use, such as assembly, business, or residential, which determines the code requirements that apply to that space.

A code category describing how fire-resistive a building's structural elements are, ranging from heavily protected noncombustible assemblies to unprotected combustible framing.

The maximum floor area permitted for a building, calculated from the base tabular area adjusted for construction type, sprinklers, and separation between buildings.

A fire-resistance-rated wall with protected openings that extends continuously from the foundation through the roof, dividing a building into separate structures for code purposes.

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

The computed number of people a space is designed to hold, found by dividing floor area by a code-specified area per occupant or by counting fixed seats.

The measured length of the route a person walks from the most remote point in a space to reach an exit, limited by code based on occupancy and sprinkler protection.

The clear capacity of doors, stairs, and corridors needed to move the occupant load out safely, commonly calculated in inches per occupant and rounded to whole units.

The period, in hours or fractions of an hour, that a building assembly withstands a standard fire test while limiting temperature rise and flame passage.

A fire-resistance-rated wall or floor assembly that restricts the spread of fire and is designed to remain in place when the structure on either side collapses.

A tested assembly of materials installed where pipes, cables, or ducts pass through a rated wall or floor to restore the assembly's fire-resistance rating.

A listed device installed inside an air duct at a rated wall or floor penetration that closes automatically when heat is detected to block fire spread through the duct.

An engineered arrangement of fans, ducts, and barriers that limits smoke movement in a building, often by pressurizing stairs or exhausting smoke from a large space.

A network of pipes and heat-activated heads that discharges water onto a fire, with design density and coverage set by the hazard of the occupancy.

A fixed piping arrangement with valves and hose connections that lets firefighters attach hoses and deliver water to upper floors of a building.

The interconnected devices that detect a fire condition and warn occupants through audible and visible signals, often also triggering smoke control and door release.

A wall that carries vertical loads from floors and roof above it in addition to its own weight, transferring those loads down to the foundation.

The maximum pressure a soil or rock can support beneath a footing without failing in shear or settling excessively under the imposed load.

The widened lower portion of a foundation that spreads a column or wall load over enough soil area to keep pressure within allowable limits.

The depth to which soil freezes in winter, used to set the minimum bottom elevation of footings so frost heave does not lift the structure.

The transient load a structure must carry from occupants, furniture, stored goods, and similar movable items, with values set by code for each occupancy.

The permanent weight of the structure itself, including framing, walls, floors, and fixed equipment, which stays essentially constant over the building's life.

The amount a beam, slab, or other structural member bends under load, limited by code to keep finishes from cracking and spaces comfortable to use.

The structural frame chosen to resist earthquake motion, such as braced frames or shear walls, each with code-assigned ductility and height limits.

A horizontal force on a building from wind or earthquake, carried to the ground by shear walls, bracing, diaphragms, or moment frames.

A sheet or coating behind exterior cladding that stops wind-driven rain from reaching sheathing and framing while allowing water vapor to escape.

The surface of a wall or roof that sheds water down and out to the exterior, formed by the weather barrier, flashing, and shingled or paneled layers.

Impervious material installed at joints, edges, and penetrations to direct water away from the building, such as at roof valleys, walls, and window heads.

A low-permeability layer placed to limit moisture diffusion through an assembly, positioned according to climate so condensation does not form inside the wall or roof.

The planned removal of surface and groundwater by grading, footing drains, and storm systems so water does not pond against or beneath a foundation.

Dividing a building into separately controlled areas so each zone's heating and cooling can be adjusted independently for comfort and energy savings.

The opening and ductwork that bring fresh air into a ventilation system, located away from exhaust outlets, loading docks, and other contamination sources.

A device that quickly shuts off a circuit when it detects current leaking to ground, protecting people in wet or damp locations from electric shock.

A breaker or receptacle device that detects the signature of a dangerous electrical arc and cuts power to prevent an electrical fire in branch wiring.

The permanent joining of metal parts to form an electrically conductive path that ensures safe fault current flow and equal potential across equipment.

A continuous, unobstructed path connecting accessible elements and spaces that meets slope, width, and surface requirements for wheelchair users.

The minimum unobstructed area needed for a single wheelchair to approach, use, or turn from a fixture, control, or element, typically rectangular in plan.

The height limits within which operable controls and dispensers must be placed so a person seated in a wheelchair can reach them without obstruction.

The boundary of conditioned space, made of insulated walls, roofs, floors, windows, and doors that separate indoor climate from outdoor conditions.

A path of high-conductivity material such as steel studs or concrete slabs that bypasses insulation and increases heat flow through an assembly.

A continuous layer that resists uncontrolled air leakage through the envelope, reducing energy loss and preventing moisture-laden air from entering cavities.

A quality process that verifies building systems are designed, installed, and operated to meet the owner's requirements before and after occupancy.

The regulatory check of construction documents for compliance with code before a permit is issued, often documented with review comments and corrections.

Required third-party observation and testing of specific high-risk work, such as structural welding or anchoring, performed by a qualified inspector and reported to the authority.

The official authorization to begin construction or alteration, issued after plans are approved and inspections are scheduled with the building department.

A document issued after final inspection confirming a completed building may be used for its intended purpose under the approved plans and code.

A field test that measures the consistency and workability of fresh concrete by the amount a standardized cone sample settles when the mold is removed.

The ability of a material such as concrete or masonry to resist being squeezed, usually measured on cured test cylinders at specified ages.

A framing method in which vertical posts carry horizontal beams and the loads travel down through the posts rather than through continuous stud walls.