Accuracy
What Groundline is accurate about, and what it is not
Publishing this is a commercial risk. Not publishing it is a bigger one, because the first customer who discovers an unstated limitation stops trusting everything else.
| Output | Accuracy characteristic | What could still be wrong |
|---|---|---|
| Parcel geometry | As accurate as the jurisdiction parcel fabric | Parcel fabric is not survey grade. Boundaries routinely differ from a field survey by a foot or more, and occasionally by much more |
| Lot area | Computed exactly from that geometry | Recorded plat acreage may differ. Where they disagree, the plat governs |
| District assignment | Exact where district polygons are authoritative | Split-zoned parcels are flagged and require a staff determination |
| Dimensional standards | Exact against the structured ordinance text | Structuring error, a superseded amendment, or a standard that only appears in a section we have not structured |
| Buildable envelope | Exact on convex parcels; grid-accurate on irregular ones | Unmapped easements, right-of-way dedications, building-code separations, and any standard we did not model |
| Unit yield | Exact arithmetic on the resolved standards | Discretionary approvals, utility capacity, stormwater, access and tree protection all reduce real-world yield |
| Construction cost | AACE Class 5 screening: −30% / +50% | It is not a bid. Subcontractor availability and site surprises dominate |
| Valuation | Reconciled indication with a published range | No interior inspection, no condition observation, no environmental review |
| Returns | Exact arithmetic on your assumptions | The assumptions. A model cannot make a wrong sale price right |
How to report an error
Every screen and every report has a "Request a data correction" action. A correction request records the field, the value we showed, the value you believe is right, and your evidence. We investigate, publish a new jurisdiction rules version, and reissue affected reports. Correction rate is a metric we track and report, not one we hide.
What we will never doWe will not publish jurisdiction content generated automatically without human verification, claim coverage we do not have, present an automated valuation as an appraisal, or let an AI approve a municipal application.