What is a written consent from the authority having jurisdiction known as?

A written consent from the authority having jurisdiction is known as "Special Permission." This term is defined within the context of the National Electrical Code (NEC) and relates to specific permissions that may be granted when certain code provisions may not be directly applicable or when alternative methods are used that still maintain safety and compliance standards.

Special Permission allows for flexibility in the application of the NEC, acknowledging that unique circumstances may require tailored solutions. This concept exemplifies the NEC's emphasis on safety, ensuring that any deviations from standard practices are still overseen by authorities who ensure compliance with overall safety standards and regulations.

The other options do not accurately capture the nature of this written consent. Regulatory Approval generally refers to broader compliance with regulations that may involve multiple aspects of safety and code provisions, not limited to electrical installations. A Construction Permit typically pertains to a broader range of construction activities and is not specific enough to denote permission regarding electrical code deviations. Safety Certification is often related to assurance that products or systems meet specific safety standards but does not refer specifically to written permissions granted by an authority regarding code compliance.