The international standard for environmental management systems - often required in tenders alongside ISO 9001/45001, and distinct from a building's own certifications like LEED or BREEAM, which rate the building rather than the organization delivering it. Where LEED or BREEAM certify the completed building's environmental performance, ISO 14001 certifies the contractor or design firm's own environmental management processes - waste handling, resource use, pollution prevention on site - a different, organization-level layer of the same broader sustainability picture.