What document must be obtained for any significant change in a building's use?

For any significant change in a building's use, a change of occupancy certificate is required. This document serves to officially acknowledge and permit the new use of the building, ensuring that it complies with zoning laws, safety codes, and regulations associated with the new occupancy type.

Building uses are often categorized into different classifications, each with distinct safety, health, and performance regulations. The change of occupancy certificate helps ensure that the building's structure, systems, and performance standards are still adequate for the new use. It often involves an inspection by local authorities to confirm that the necessary upgrades or changes—such as fire safety measures, accessibility features, or HVAC system adjustments—have been made.

Other documents like building permits, structural permits, and design approvals are important in various stages of building construction and modifications but do not specifically focus on changes in occupancy and the implications that such changes have on safety and compliance.