Data sources
Every source, its licence, and how we get it
Data provenance is the product. This page is generated from the same registry the engines cite.
| Source | Publisher | Kind | Acquisition | Refresh | Review | Legal basis for use |
|---|---|---|---|---|---|---|
| Harlow / Marston County parcel fabric | City of Harlow (fictional) | demonstration | synthetic | static | expert reviewed | Authored by Groundline for demonstration and testing. Contains no third-party data. |
| Harlow Municipal Code Title 17 (Zoning) | City of Harlow (fictional) | demonstration | synthetic | on change | expert reviewed | Original text authored by Groundline. Not derived from any real municipal code. |
| Harlow County Assessor property records | Marston County Assessor (fictional) | demonstration | synthetic | quarterly | analyst reviewed | Fictional records. Owner names do not identify any real person. |
| Marston County Register of Deeds | Marston County (fictional) | demonstration | synthetic | weekly | analyst reviewed | Fictional records. |
| Harlow area transaction set | Groundline (synthetic) | demonstration | synthetic | static | analyst reviewed | Synthetic transactions. In production, listing and closed-sale data requires an MLS data licence (IDX/VOW or a data-access agreement) or a licensed vendor feed; Groundline will not ingest MLS content without one. |
| Harlow regional construction cost basis | Groundline (synthetic) | demonstration | synthetic | quarterly | analyst reviewed | Synthetic parametric rates. Production rates come from a licensed cost service plus locally-collected bid data. |
| Groundline Reference Plan Library | Groundline | demonstration | manual entry | on change | expert reviewed | Original plan metadata authored by Groundline. No third-party drawings are stored or displayed. |
| Fulton County Tax Parcels | Fulton County, Georgia (Board of Assessors / GIS) | official gis | arcgis rest | monthly | machine extracted | Parcel geometry, address, ownership and assessed values are public tax records. Used for parcel identification, geometry and preliminary assessed-value context. Not a substitute for a boundary survey. |
| City of Atlanta Zoning Districts | City of Atlanta, Department of City Planning | official gis | arcgis rest | on change | machine extracted | Base zoning-district geometry and class code, used to determine the governing district by centroid spatial join. The authoritative district for a parcel is an official zoning determination by the City; this is a preliminary indication only. |
| Dallas Tax Parcels (DCAD via City of Dallas) | City of Dallas GIS / Dallas Central Appraisal District | official gis | arcgis rest | monthly | machine extracted | Parcel geometry, account number, address and property class. Texas is a non-disclosure state, so sale prices are not in the public record and are absent by law. |
Known limitations by source
Harlow / Marston County parcel fabric
- Parcel boundaries are informational and are not derived from a boundary survey.
- Easements are recorded only where a plat note describes a parallel strip; blanket easements are not modelled.
Harlow Municipal Code Title 17 (Zoning)
- The contextual front setback in the HD-1 overlay cannot be resolved from the text; it requires a written determination.
- C-2 dimensional standards are summarised from the district table rather than a dedicated section.
Harlow County Assessor property records
- Assessed value is a tax basis and is not a market value indication.
- Owner mailing addresses are withheld from all responses in the demonstration dataset.
Marston County Register of Deeds
- Instrument text is not reproduced; only date, price and instrument type are structured.
Harlow area transaction set
- Condition and effective age are self-reported fields and are the weakest link in any adjustment grid.
Harlow regional construction cost basis
- Parametric rates are AACE Class 5 screening accuracy: −30% / +50%.
Groundline Reference Plan Library
- Footprints are modelled as rectangles from published width and depth; articulated footprints will fit more tightly than the model suggests.
Fulton County Tax Parcels
- Geometry is assessor cadastral data, not a survey; boundaries are approximate.
- A parcel modelled as a MultiPolygon is reduced to its largest part for feasibility.
City of Atlanta Zoning Districts
- The governing district is assigned by parcel-centroid point-in-polygon; a split-zoned parcel is flagged boundary-uncertain and requires an official determination.
- District geometry gives the class code only; dimensional standards come from the zoning ordinance via the extraction pipeline, not from this layer.
Dallas Tax Parcels (DCAD via City of Dallas)
- No sale prices (Texas non-disclosure); comparables require MLS/IDX or a licensed aggregator.
- Base zoning district is NOT available from Dallas public GIS (zoning is published as ordinance case-tracts). Zoning for Dallas parcels is unavailable until the Development Code PD system or a licensed product is integrated.
Acquisition policy
- Government open-data portals, GIS services and ordinance repositories, used under their published terms
- Licensed vendor feeds under written agreement
- MLS content only under an IDX, VOW or data-access agreement — never scraped
- Customer-provided data, used only for that customer
- Partner integrations under written agreement
- No unauthorised scraping, and no ingestion of any source whose terms prohibit it
- Owner mailing addresses and other personal data withheld unless the tenant is entitled to them and the use is lawful