What factor determines whether an alteration to a building requires a structural revision?

The factor that determines whether an alteration to a building requires a structural revision is if the alteration affects load-bearing elements. Load-bearing elements are critical components of a building's structure, as they support the weight of the building and any additional loads, such as occupants, furniture, and environmental factors like snow or wind.

Altering these elements can significantly compromise the structural integrity of the building, leading to safety hazards or even structural failure. For instance, removing a load-bearing wall or modifying a foundation without proper engineering assessments and revisions could destabilize the entire structure. Therefore, any alterations that impact these essential components necessitate a thorough evaluation, potentially requiring revisions to the structural plans, demonstrations of compliance with safety codes, and possibly obtaining new permits.

Other considerations, such as energy efficiency improvements, zoning laws, or the temporary nature of the alteration, do not inherently indicate a need for a structural revision. While enhancing energy efficiency may be beneficial and must comply with code, it doesn’t directly relate to structural integrity. Similarly, zoning laws govern land use and occupancy but do not dictate structural requirements. Temporary alterations may not compromise the structural elements and, therefore, may not require a formal revision unless those elements are impacted.