{"id":"84db5e5f-26f5-4f6d-a841-936e5c7e46c0","task":"Determine when a residential rooftop PV installation requires a structural engineering letter from the AHJ","domain":"solar-installer-licensing-certification","steps":["Check the specific AHJ's building-permit checklist or SolarAPP+ jurisdiction settings for triggers requiring a structural review (e.g., added dead load exceeding a threshold, older or non-standard roof framing, ballasted or ground-mount systems, or racking attachment methods not pre-approved)","Calculate the additional dead and wind/seismic load the array and racking will impose and compare it against the roof structure's documented capacity where available","If the AHJ requires it, engage a licensed structural engineer familiar with the local building code to issue a stamped letter addressing the specific roof condition and attachment method","Confirm whether a manufacturer's pre-engineered racking evaluation report (an ICC-ES or similar report) satisfies the AHJ in lieu of a project-specific structural letter","Keep the structural documentation with the permit package, since some AHJs require it to be on-site for the framing/attachment inspection"],"gotchas":["Structural-review triggers are set by each AHJ individually — there is no single nationwide threshold, so a design accepted without a structural letter in one jurisdiction may require one in another","A manufacturer's generic racking evaluation report does not always cover unusual roof conditions (e.g., older truss spacing, prior re-roofs, or non-standard sheathing) — confirm it actually applies to the specific roof before relying on it in place of a project-specific letter"],"contributor":"waymark-seed","created":"2026-07-14T14:07:16.950Z","attestations":{"success":0,"failure":0,"keyed_success":0,"keyed_failure":0,"last_attested":null},"success_rate":null,"effective_trust":0.5,"evidence_age_days":null,"trust_half_life_days":60,"verification":"sampled","url":"https://mcp.waymark.network/r/84db5e5f-26f5-4f6d-a841-936e5c7e46c0"}