Help · Roof packet accuracy
Roof packet accuracy.
How the measurements are produced, what the tolerances are, and what happens when LiDAR coverage falls short.
Source data
USGS 3DEP LiDAR (1-meter or 1-foot point cloud, depending on coverage tier) plus Microsoft Building Footprints v2 (129M buildings). For Florida and select states with statewide LiDAR, the resolution is 1 foot — sub-meter accuracy on roof geometry.
Premium-grade accuracy
Engineered to industry-spec parity on Florida residential: ±3% area, ±0.5° pitch, exact facet count. See the methodology page for the tolerance standard and the per-state coverage map; published validation results land as the benchmark cohort completes.
Coverage gaps
Some states do not have statewide LiDAR. For those, SkyCanvass falls back to derived geometry from Microsoft Footprints + 2D imagery — accuracy drops to ±8% area, no pitch. The packet flags the data source in the header.
When LiDAR is not enough
If LiDAR coverage is missing, or the roof was modified after the most recent flight, the packet falls back to derived geometry and flags it in the header. On-site ground-photo capture for point-in-time geometry is in development.
How accuracy is measured
Two metrics: total roof area (square feet) and per-facet pitch (degrees), benchmarked against ground-truth measurements. The methodology page documents the tolerance standard each packet is held to.
When to challenge a packet
If a SkyCanvass packet differs from a ground-truth measurement by more than the published tolerance (±3% on FL residential, ±8% elsewhere), email support@skycanvass.com with the packet ID. Challenges are triaged within one business day and a corrected packet issues at no charge.
Why LiDAR works
LiDAR captures a 3D point cloud of every surface in the flyover area. Roofs are clearly visible in the data. Modern processing pipelines extract plane segments (the facets), compute pitch from the plane normal, and measure area from the boundary polygon. The math is the same as what manual measurement does — the LiDAR just gives a denser, more accurate input.
When LiDAR is older than the most recent roof modification (a re-roof, an addition), the packet can be wrong. SkyCanvass shows the LiDAR vintage in every packet — a 2022 LiDAR flight serving a 2024 re-roof would be visible. In that case, request a re-measurement with current imagery, or use a point-in-time on-site measurement instead.
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