A design team is permitting a 15-kW residential array on a mountain home at 7,500 ft with 60-psf ground snow, 120-mph wind exposure, and a known seismic zone on composite shingles. The AHJ wants stamped racking proof. Which location-load review should the designer require to approve the racking and attachment plan?

The correct review requires listed racking supported by site-specific stamped calculations covering combined 120-mph wind uplift and lateral pressure, 60-psf ground snow with drift, sliding and unbalanced cases at 7,500 ft, and seismic forces with appropriate rail, splice, clamp and lag or through-bolt capacities verified at actual attachment spacing and spans for composite shingles. The cut-sheet-only approach fails by concept because published capacities without a licensed stamp do not satisfy the AHJ demand for stamped proof and cannot certify combined-load interactions at project spacing. The standard-table approach fails by concept because generic spans assume moderate default wind, snow and seismic inputs and therefore cannot be extrapolated to high mountain snow, high wind exposure and a known seismic zone where spacing must be reduced and pullout rechecked. The tile-hook approach fails by concept because hooks, flashing and fastener pullout values qualified for tile profiles do not transfer to composite shingle decks, creating waterproofing and structural mismatch despite correct load math. Exam caveat: do not equate listing with engineering approval, since listing proves component testing while the stamp proves site load-path compliance. Practical check: require the engineer letter to cite project address, elevation, design wind speed, ground snow load, seismic category, shingle attachment type, maximum attachment spacing and span, and rail cantilever limits before approval.