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Roof Measurement Case Studies

Last reviewed: August 5, 2026

A useful roof measurement should be reviewable, not merely precise-looking. These case studies document what the satellite source detected, what a homeowner could verify in the property image, how the outline changed, and how that correction affected material quantity and the planning range.

Case 01: A garage partly hidden by mature trees

This nearby Kent County test property was selected because tree cover obscured part of the garage and roof edge. It is not presented as an East Grand Rapids market average. Google Solar supplied the initial roof geometry; the homeowner then reviewed and corrected the displayed outline.

Satellite roof surface1,919 sq ft
Reviewed roof surface2,465 sq ft+28.5% after outline review
Order area with waste2,835 sq ft15% cut-up geometry allowance

Why the result changed

The satellite measurement described the roof it could identify, but the property image showed that the roofing project included more area. The correction replaced the original measurement with the complete homeowner-drawn footprint, applied the selected pitch to convert footprint into roof surface, and then applied the configured waste factor.

Stage Measurement basis Planning range
Automatic Google Solar roof surface without correction $11,900-$15,200
Reviewed Corrected footprint, pitch-adjusted surface and waste $14,900-$19,000

A second careful outline adjustment produced essentially the same planning range. That consistency supports the correction, but it does not turn the result into a certified measurement or contractor proposal.

What this example teaches

  • Tree cover can hide a meaningful connected roof section.
  • The property image and highlighted outline matter more than the apparent precision of one number.
  • Roof surface and order area with waste are different quantities and should be labeled separately.
  • A large correction should be visible to the homeowner before pricing continues.
  • An on-site inspection still needs to verify roof edges, pitch, layers, decking and final material quantities.

Status: homeowner-reviewed planning measurement. The figures have not been represented as an on-site inspection, certified roof report or contractor material order.

Review your own outline

Open the Roof EGR estimator and compare the highlighted roof with the house, connected garage, additions and areas hidden by trees.