Methodology

What actually happens when you check a roof · July 23, 2026

1. Address resolution

The address is resolved with the U.S. Census Geocoder. A rooftop-quality match can pre-highlight a building; a street-interpolated match cannot prove which building is yours — so the structure must always be confirmed by you.

2. Structure identity and scope

Nearby building outlines (OpenStreetMap/Overture, ODbL) are drawn over observed USDA NAIP aerial imagery when available. You tap the roof to measure, add any additional structures explicitly, and confirm the outline covers every roof section you want. No number appears before both confirmations. An unresolved scope conflict stays red.

3. Measurement

• Ground footprint is the geometric union of your confirmed outlines — overlaps are never double-counted, and it is kept distinct from sloped roof surface.
• Sloped surface is modeled with a typed pitch prior (3/12–9/12, central 6/12) shown as an honest range — or computed from a pitch you enter, applied exactly once.
• Waste and order quantities are calculated per structure, then totaled. Planning quantities are never order-ready.
• Unknown values are shown as Unknown — never as zero.

4. Evidence labels

Observed imagery is labeled with its source and date (for example “Observed aerial imagery · USDA NAIP”) and is not a survey. Derived geometry is always labeled as derived. Generated imagery is never used as property evidence. LiDAR coverage, where found, is noted but does not change a measurement until roof points are actually processed.

5. What we refuse to do

• No silent measurement of a nearby building.
• No fixture or demo data substituted into a live check.
• No premium-report purchases behind your back.
• No accuracy or savings claims that the evidence does not support.