Unfinished Spaces: Areas not intended for habitation or regular occupancy, including those used for warehouse, industrial, or other intended business operations and spaces under construction. These spaces typically lack general finish materials and may also include attics, basements, crawlspaces, plenums, and under-roof areas.

Unit Identifier: A label or placard on MEP equipment and its related components that indicate its reference details, which may include numbers, letters, or a combination thereof, as assigned by the building owner, manager, or maintenance personnel.

Unsafe: In the inspector’s opinion, a condition of an area, system, component or procedure that is judged to be a significant risk of injury during normal, day-to-day use. The risk may be due to damage, deterioration, improper installation, or a change in accepted commercial construction standards.

Use and Occupancy: Classifications established by the IBC® that are the design loads for categorized structures based on usage in pounds per square foot.

UV (Ultraviolet) Degradation: A reduction in performance caused by exposure to sunlight.