A 9 kW home retrofit in a historic district needs a building permit, utility interconnection approval, and final sign-off before permission to operate. In this jurisdiction the utility reviews an interconnection application only after the AHJ approves the plans, its approval is required before construction, and the AHJ's final inspection must pass before anyone energizes. The designer must explain the sequence and who enforces each step. Which explanation best describes permitting, utility, and AHJ inspection requirements?

The required sequence is AHJ plan approval, utility interconnection approval, and then a passed AHJ final inspection before operation. The AHJ (authority having jurisdiction) reviews the plans and issues the building permit; the utility reviews the proposed grid connection only after that approval and grants interconnection approval; the AHJ then inspects the completed work and provides final sign-off. This keeps each authority’s role distinct. The explanation that would energize after utility authorization while final inspection remains pending fails because utility approval does not replace the required AHJ inspection sign-off. The explanation that completes final inspection before securing utility interconnection approval fails because the utility review follows AHJ plan approval and precedes final sign-off in this scenario. The explanation that seeks utility approval before AHJ plan approval fails because it reverses the required initial steps. An exam caveat: actual utility procedures may allow applications or technical reviews to run in parallel with permitting, but that does not make permission to operate interchangeable with AHJ approval or final inspection. As a practical check, confirm the local AHJ’s permit and inspection checklist and the utility’s written interconnection milestones, including the explicit authorization required before energizing.