wall-framing-takeoff splits long walls into transportable shop panels and gives each a handling weight: lumber, plus sheathing at a typed lb per sq ft. Gable-end walls were left at zero sheathing weight, so the heaviest panels in a house, the ones with a triangle on top, looked lighter than they are.
A gable wall now records its eave height. Each panel's sheathed area is the eave rectangle plus the triangle under its span, split at the peak when a panel straddles it, less openings. The test checks that panel areas add up to the whole wall's rectangle plus triangle, for one panel and for a wall split in three. It is a handling estimate, as before, not a load figure.