Sources & limits

Where this comes from, how current it is, and what it can’t tell you.

Who actually makes this data

Assessor of Property Records who owns what, what’s on it, and what it’s worth. A separate elected office — not MetroGIS.

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MetroGIS Publishes those records as a map layer, and adds geometry, flood hazard and aerial imagery.

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Metro Land Normalizes the owner names and classifies each parcel. Everything this project adds is a rule you can read.

Zoning comes from Metro Planning. Nearly everyone credits MetroGIS for all of it — that’s wrong, and it hides the update cycle below.

Three things to know before you use it

3 yrs How stale it can be The Assessor field-reviews a third of parcels a year on a four-year cycle. So “vacant” means the last review found no building — which may have been three years ago.

3.4% Known error rate Every published parcel was checked against OpenStreetMap buildings, and every flag was then checked by eye on aerial photos. Seven were wrong. We fixed them and we’re telling you the number.

1,909 Restriction unknown No deed-restriction data exists for Davidson County. A parcel with no flag hasn’t been cleared — it just hasn’t been checked.

We checked our own work

OpenStreetMap buildings are traced from aerial photos by people with no connection to the Assessor. If one sits inside a parcel we call vacant, one of us is wrong.

196 clean 7

No building — claim holds Had a building — found, checked, corrected

Every parcel OSM flagged was then looked at on aerial photography. Seven really did have buildings and are corrected. Two were false alarms — one empty lot, one surface parking lot — and were left alone.

A measured error rate of 3.4%, not an estimate. The most instructive miss: 520 26th Ave N is Fire Department Station 19, recorded as vacant commercial land. Switch on aerial imagery over any parcel and you can check us the same way in about five seconds.

How the audit ran, and the eight

For all 229 parcels published as unimproved and unrestricted, we pulled every OSM building in the parcel’s bounding box and tested whether a building’s centroid falls inside the parcel — not just whether footprints overlap, since a building clipping a boundary is usually the neighbour’s.

Overlap	Acres	Zoning	Address
47.6%	1.04	MUI-A	520 26th Ave N
46.6%	0.16	CS	1717 Jo Johnston Ave
34.3%	0.17	R6	2220 15th Ave N
33.3%	0.17	R6	2224 15th Ave N
32.6%	0.17	RS5	1039 43rd Ave N
32.3%	0.17	RS5	1035 43rd Ave N
20.4%	2.41	R6	601 Benton Ave
18.1%	0.20	R6-A	1706 7th Ave N

All eight are classified by the same rule, cat-050, which trusts the Assessor’s land-use code. So either that code is stale or OSM is. Reproduce with scripts/audit_buildings.py.

The sources

Parcels

MetroGIS → Cadastral/Parcels 2,915 government parcels, pulled 2026‑08‑11. Owner, land use, acreage, zoning, geometry. The spine of everything.

2010 flood damage

MetroGIS → May2010Flood 11,647 parcels with a damaged structure. Joining this to Water Services ownership identifies 306 buyout parcels outright, instead of guessing.

FEMA floodplain

MetroGIS → Hydrography 5,156 flood hazard polygons adopted by FEMA and Council. Drives the floodway and floodplain flags.

Aerial imagery

MetroGIS → Imagery Twelve years, 1996 to 2023 — plus photos taken during the May 2010 flood itself. Available as a layer on the map.

Public Property Inventory

Metro General Services, 2025 2,247 rows; 99.6% join to ours on parcel ID. not independent

OpenStreetMap

overpass-api.de — ODbL Building footprints, used only to check our work. Never an input to any classification.

Unified Housing Strategy

Metro Planning, 2025 Names ~27 candidate sites and directs Metro to inventory its land. released, not adopted

Council legislation

nashville.legistar.com RS2026‑1800 and RS2025‑1147. No Council bill has ever asked for an inventory of Metro-owned land — part of why none existed.

Which field comes from where

Field	Who makes it	What it decides here
`Owner`, `OwnDate`	Assessor	Entity, department, buyout dating
`LUCode`	Assessor	Whether a parcel counts as unimproved
`LandAppr`, `ImprAppr`	Assessor	Context only — never classification
`Acres`, `STANPAR`	Assessor	Size filter; join to flood records
`Zoning`	Metro Planning	The rezoning cross-tab
Geometry	MetroGIS	The map; floodplain intersection

Improvement value is deliberately unused. 83% of government parcels report $0 — including the Courthouse and Cane Ridge High — because Metro doesn’t assess its own tax-exempt property. Trusting it would list the courthouse as vacant land.

Things that look like corroboration but aren’t

The 2025 Public Property Inventory. It shares our owner vocabulary down to the same typos, so General Services is almost certainly generating it from the same parcel layer. Agreement proves nothing. It also contains zero MDHA rows despite being described as inclusive of MDHA — for those 639 parcels the parcel layer is the only source.
The Unified Housing Strategy. Released by Planning and the Mayor’s Office. No adopting ordinance or resolution exists. Council funded it ($69M, FY2026‑27), but funding is not adoption.
The East Bank flag. Those 14 parcels are identified by a shared 2023‑08‑25 acquisition date, not from the master development agreement, which we don’t have.

What this still can’t tell you

Deed restrictions. No layer exists for Davidson County. unknown means unchecked, not clear.
Whether a parcel is truly available. We flag the East Bank, MDHA projects and Metro’s named candidates. That list isn’t exhaustive.
Current condition. Nothing here is a site visit.

Using it

The classification — every rule and every column this project computes — is public domain under CC0. Take it. Source data keeps its own terms: MetroGIS and the Assessor of Property for parcels, ODbL for OpenStreetMap. Not affiliated with or endorsed by Metro Nashville.

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