4.1
City published
27at 200 ft
1at 500 ft
Direct release from JC Planning & Development Services. Configuration and methodology not published at time of writing. No data reported past 500 ft.
1
Ordinance text
"No Data Center facility shall be located within 200 feet of any residential use or district. This includes any zoning district that permits single family residences or dwellings, as well as RM-3, RM-4, and RM-5 districts. The measurement shall be made from the nearest property line or zoning line of the residential use or district, whichever is closer, to the nearest property line of the Data Center." Draft §6.20.3.2.I
"The minimum front yard setback shall be sixty (60) feet. The minimum side and rear setbacks shall be fifty (50) feet." Draft §6.20.3.2.I (Data Center yard setbacks)
Separation distance
200 feet
Measurement basis
Property line to property line
DC's own yard setbacks
60 ft front, 50 ft side/rear
Consequence of the property-line basis
Eligibility moves when lot lines are redrawn
One further constraint is used in Section 4.4 only: the City's general I-2 lot requirements demand at least 50 ft of frontage on a public right-of-way, which binds any newly-created lot. No other constraint is imposed anywhere in this analysis. In particular, no minimum facility size is assumed, because the ordinance sets none. Parcel counts below therefore include sites whose maximum building envelope is small; envelope size is reported so readers can judge practicality.
2
Published city counts
Data released by JC Planning & Development Services. Underlying methodology not disclosed at time of writing. Records requests pending.
| Separation | Parcels | Acres |
|---|---|---|
| 200 ft | 27 | 62.45 |
| 250 ft | 26 | 62.35 |
| 300 ft | 18 | 37.87 |
| 350 ft | 12 | 25.62 |
| 400 ft | 9 | 20.16 |
| 450 ft | 3 | 9.80 |
| 500 ft | 1 | 0.64 |
No published counts beyond 500 ft. The single parcel reported at 500 ft is not identified by the city; the only candidate parcel whose acreage matches the published 0.64 ac is 090054L D 00600 (Lafe Cox Drive, Automated Building Systems). In the public GIS that parcel sits 534.6 ft from the nearest residential line, consistent with the city's plain 500 ft test. It also qualifies at 500 ft under the methodologies below. After the ordinance's own 50 ft yard setbacks, though, its maximum building envelope is roughly 720 sq ft (about 26×26 ft), an example of why envelope size is reported alongside every count.
3
Interpretation spectrum
The same ordinance text and the same GIS data support a wide range of eligible-parcel counts at 200 ft, depending on which defensible methodology is applied. The methodologies are defined in Section 4.
Horizontal axis is to scale (linear in feet). City published data ends at 500 ft; the count-fit reconstruction of the city's numbers (Section 4.2) is extended past 500 ft for reference.
4
The methodologies
The draft's measurement rule is explicit: property line to property line. Methodologies 4.3 and 4.4 apply that rule as written; they differ only in whether the property lines are today's or ones a developer could lawfully redraw. 4.2 reconstructs the city's published counts. 4.5 is not a reading of the draft. It is the alternative rule this analysis recommends adopting by amendment (Section 6), shown here for comparison. All use the same residential-exclusion universe (Section 7) except 4.2, which uses the narrower set that best matches the city's counts.
4.2
Count-fit reconstruction of the city's numbers
–at 200 ft
–at 500 ft
Working backwards from the city's own count-and-acreage arithmetic, the full 27-parcel list behind the published table has been identified: the unique assignment that reproduces the city's cumulative counts and acres at every published tier within the table's own rounding. It is mapped, parcel by parcel, at the city parcel reconstruction page. The implied method is plain parcel-boundary distance, with no padding, measured to residential zoning districts inside the city and to county residential land beyond the city limits. Residential uses inside the city were not counted; one identified member has a single-family residence 79.6 ft away, yet the city placed it in the 450 ft tier. Two consequences matter for this ordinance. First, nine of the city's 27 parcels cannot hold any building under the ordinance's own 50 ft yard setbacks; the published counts measure the separation clause in isolation. Second, 24 other industrial parcels equally far from residential are absent from the counts for reasons no systematic rule explains. The pending records request should resolve that. (The dashed chart line is the simpler count-only approximation, retained for reference.)
4.3
Parcel-to-parcel, existing lots
–at 200 ft
–at 500 ft
A parcel qualifies when its entire boundary is at least the separation distance from any residential zoning polygon or any parcel containing a residential use. That is property line to property line, matching the ordinance text verbatim, on lots as they exist today. One further ordinance-derived requirement applies: a building location must exist on the lot at all, i.e. some I-2 land remains after the DC's own 50 ft yard setback from the lot lines. No minimum size beyond that.
4.4
Parcel-to-parcel, with subdivision
–at 200 ft
–at 500 ft
Everything in 4.3, plus parcels where a new lot could be drawn that passes the same test. The new lot must sit entirely at least the separation distance from residential (otherwise its own property line violates the ordinance), must take at least 50 ft of public-road frontage on its own boundary (City I-2 lot requirement), and must retain a building location after the DC's 50 ft yards. A lot line drawn at the separation contour therefore puts the building itself at least separation + 50 ft from residential. Assumes a lot-line adjustment or subdivision is available to the developer.
4.5
Parcel-to-structure (proposed rule)
–at 200 ft
–at 500 ft
Not the draft as written; the draft measures to the Data Center's property line. This is the amendment recommended in Section 6: measure to the building instead. A parcel qualifies when some building location on the existing lot (on I-2 land, at least 50 ft inside the lot lines per the DC's own yard setbacks) is at least the separation distance from residential. Subdivision cannot change the count, because redrawing lot lines never moves the test. The test runs to the building's location, not to a boundary.
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Subdivision changes the count under parcel-to-parcel
Subdivision (or lot-line adjustment) is available to any property owner under JC subdivision regulations. Under parcel-to-parcel, a non-compliant parent parcel can be resolved into a compliant new lot by drawing a lot line at the separation contour. Under parcel-to-structure, the count is fixed regardless.
Parcel-to-parcel
| Separation | Existing lots | With subdivision | Gain |
|---|
"With subdivision" counts every parcel eligible when subdivision is available: those usable as-is (4.3) plus those that qualify only after drawing a new lot line. The gain column is the count of parcels eligible only through subdivision.
Parcel-to-structure (proposed)
| Separation | Eligible | With subdivision | Gain |
|---|
The test is applied to the building's location rather than a moveable parcel boundary. New lot lines can only shrink the area where a building may stand, never expand it, because each new line brings its own 50 ft yard. Subdivision cannot add parcels.
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Recommendation: 500 ft, parcel-to-structure
Adopting 500 ft parcel-to-structure as the separation rule produces a pre-identified set of eligible parcels that is not sensitive to subdivision and enforces a real 500 ft separation between the DC building and any residential property line.
| 200 ft parcel-to-parcel |
500 ft parcel-to-parcel |
500 ft parcel-to-structure |
|
|---|---|---|---|
| Eligible parcels, existing lots | – | – | – |
| Eligible parcels, with subdivision | – | – | – |
| Subdivision changes the count | Yes | Yes | No |
| Guaranteed DC-building distance to residential | 250 ft | 550 ft | 500 ft |
| Verifiable at building permit | Requires re-measure if lot lines change | Requires re-measure if lot lines change | Building coordinates against residential parcel |
Why this combination
- A. The eligible set is fixed.
- Parcels can be pre-identified and published. Subdivision does not change the count because the compliance test is against the building's future location, not a parcel boundary that can be redrawn.
- B. 500 ft is measured to the actual DC building.
- The distance the amended rule would enforce is 500 ft between the DC building and any residential property line. The DC building's location is verifiable at building permit review. (Under the draft's 200 ft property-line rule, the guaranteed building distance is only 250 ft: 200 ft to the lot line plus the 50 ft yard.)
- C. Not vulnerable to a "no available sites" challenge.
- Dozens of industrial parcels remain viable. The comparable count under 500 ft parcel-to-parcel on existing lots is far smaller, raising legal exposure to a challenge that the ordinance effectively prohibits the permitted use.
- D. Not vulnerable to a subdivision workaround.
- Under 200 ft or 500 ft parcel-to-parcel, a developer can obtain eligibility on an otherwise-non-compliant parcel by drawing a new lot line. Under parcel-to-structure, this workaround produces no change.
Adoption of this rule would require amending the measurement clause of §6.20.3.2.I to run to the Data Center building or structure rather than to its property line, and setting the separation distance to 500 ft. Because no minimum facility size is assumed, some eligible parcels can hold only a small building; the published parcel list includes each parcel's maximum building envelope so the Commission can see exactly what each site supports.
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Methodology and data
- GIS layers
- Parcels, Zoning, Addresses, and Road Centerlines. Sourced from JC Planning & Development Services public GIS release. Distances computed in Tennessee State Plane US Feet (EPSG:2274).
- Residential exclusion universe
- Residential zoning districts (R-1 through R-6 including the R-2A/B/C variants, RP-2 through RP-6, RO-1, RO-2, A-1, and RM-3 through RM-5) plus parcels with a residential use, meaning a residential tax-roll LANDUSE code or a dwelling address point in the 911 address database.
- LANDUSE handling
- Tax-roll LANDUSE codes are used as a fallback residential signal but disbelieved when contradicted by the address record's PLACETYPE (e.g., LANDUSE = 11 "household units" but address PLACETYPE = "government facility"). Parcels with residential LANDUSE, zero address points, and industrial (I-1 or I-2) declared zoning are also excluded from the residential set.
- Rail parcels
- Parcels with LANDUSE = 41 "rail transportation" or with railroad owner names are excluded from both the candidate set (cannot host a facility) and the residential offender set (misassigned address points on linear ROW polygons produce false positives).
- Building envelope
- The area of a lot where a compliant DC building could stand: the lot's I-2-zoned land at least 50 ft inside every lot line, per the DC's own yard setbacks in §6.20.3.2.I. The 50 ft figure is the smaller of the ordinance's yards (60 ft front / 50 ft side and rear), so envelopes are a slight over-estimate along one frontage side; counts are correspondingly an upper bound. A 1 sq ft numerical noise floor is the only size threshold anywhere in the analysis; per-parcel envelope acreage is published in every output CSV. Sensitivity knobs exist in the scripts for readers who want to impose a minimum building size; none is imposed here.
- Road frontage
- Applied only in 4.4, where a new lot is created: the City's I-2 lot requirements demand 50 ft of public right-of-way frontage. Frontage is measured on the boundary of the proposed new lot (the clear portion of the parent parcel), not the parent parcel as a whole. Existing lots of record (4.3, 4.5) are used as-is: their access is already legally established. Frontage is approximated as parcel boundary within 50 ft of a public road centerline.
- Reproducibility
- Complete source at git.davidadams.rocks/dave/200feet. Every number on this page is read from data/commission.json, generated by scripts/analyze.py (eligibility tiers), scripts/city_fit.py (city reconstruction), scripts/city_guess.py (parcel-level identification behind the reconstruction map), and scripts/commission_data.py (assembly) from the published GIS layers. Per-parcel audit trails with distances, disqualification reasons, and assessor links are in out/audit_*.csv.