1. Source and scope
The property database begins with the Polk County Assessor’s Commercial Inventory for Polk County, created August 16, 2026. Records are limited to City of Des Moines parcels with exempt or mixed exempt class codes. The file supplies owner, occupant, address, value, classification, physical characteristics, and map coordinates. Government-owned property and strictly residential-class exempt property do not appear in this commercial inventory and are not included in the 796-record total.
2. Net exempt value
For fully exempt parcels, net exempt value equals the Assessor’s full assessed value. For the 31 partially exempt parcels, the portion still reported on the tax roll is subtracted:
Net exempt assessed value = full assessed value − taxed portion
3. Practical categories
Individual records are grouped into Hospital, School, Church, Charitable, Care Facility, and Other using the county’s occupancy and occupancy-group fields. These are navigation labels, not legal determinations. The separate history pages retain the Assessor’s own statutory category names.
4. Coordinates
The export’s Iowa State Plane South coordinates were converted to WGS84 latitude and longitude. Three records lack usable coordinates and remain searchable but do not appear on the map.
5. Tax scenarios
Iowa applies a rollback before the consolidated levy. The two scenarios use the same net exempt value and dominant Des Moines City / Des Moines Schools rate, changing only the rollback:
Scenario = net exempt value × rollback × (42.32446 ÷ 1,000)
| Scenario | Rollback | Question answered |
|---|---|---|
| Residential | 0.445345 | What if the value were treated like a homeowner’s property? |
| Commercial | 0.900000 | What if the value were treated like a business property? |
6. Validation
The parcel-level sum was compared with the Assessor’s independent City of Des Moines category table. The two sources agree to approximately 99.979%, a difference of about 0.021%. The residual can reflect timing, classification, or rounding differences between county products.
7. Editorial review
Code and AI tools assisted with cleaning, calculation, drafting, and presentation. Primary records remain the authority. AI output does not alter the database automatically; public corrections require human review and are logged.