Measurement accuracy has a resolution cliff, and big roofs fall off it
Automated roof measurement works beautifully on a 20-square suburban gable and then quietly fails on the jobs worth the most money. The reason is resolution: tracing runs against imagery sampled at a fixed scale, and past a certain roof radius the sampling can no longer resolve the edges. The trace either collapses, bleeds into the neighbour's roof, or returns an area confidently wrong by a quarter.
That is a brutal failure mode, because it fails on the large, complex, high-value roofs — exactly the ones where an estimator most wants help and least wants to double-check a machine.
Fixing it is unglamorous engineering: scale the sampling with the roof, cap the vertex budget so the outline stays a roof and not a noisy blob, clip the bleed into adjacent structures, and heal the gaps only where the geometry genuinely justifies it. Then verify against real addresses rather than a demo, comparing traced area and corner deviation before and after every change. We keep a harness that does exactly that, because a measurement change that looks fine on one house can be a systematic 25% error on another.

