Knowledge of Applicable Codes and Ordinances
This domain tests whether you can identify the code edition and local rules that govern a PV installation and apply them during an inspection. The inspector does not choose a favorite edition; the authority having jurisdiction (AHJ) adopts a specific NEC edition, and local amendments, zoning, fire, structural, and utility interconnection requirements may be stricter.
Sources of authority
- NEC edition adopted by the AHJ, plus amendments; confirm before inspecting.
- International Residential Code (IRC) and International Fire Code (IFC) roof access and pathway provisions, typically IRC R324.6.2 / IFC 1204.2.
- Utility interconnection rules, net-metering tariffs, and manual lockable disconnect requirements.
- Local zoning, historic, coastal, snow-load, and HOA conditions, plus contractor licensing.
Applying the stricter rule
Where documents conflict, the adopted code and local amendment control; a utility requirement can exceed code but cannot relax it. Record the edition and section you rely on.
Worked example
A permit set references the 2020 NEC, but the AHJ amendment requires 36 in. clear pathways on residential roofs and the utility requires an exterior lockable AC disconnect. The array leaves only 18 in. at the ridge and has no exterior disconnect. Reasoning: check the amendment first-the pathway fails; check the utility tariff-the disconnect fails. Both are valid nonconformances even though the NEC itself may not contain the 36 in. pathway rule. The correction is a redesigned layout and an added disconnect, not a verbal waiver.
Traps
- Inspecting to the newest NEC rather than the adopted edition.
- Treating a utility rule as optional because it is not in the NEC.
- Missing fire-department access pathways on townhomes and multifamily roofs.
- Assuming an older permit is grandfathered without written AHJ confirmation.