Description
Subtract referenceElevation from topElevation for heightAboveReference.
Urban-design quantities depend on the measured boundary and denominator. Building height, parcel area, street width, and setbacks describe different geometric constraints and should use a common length or area basis.
Subtract referenceElevation from topElevation for heightAboveReference.
When to use this tool
Use Zoning Height Reference Offset when you need one planning geometry component from supplied dimensions before a wider design review.
How to use the tool and how it works
- Enter topElevation, referenceElevation. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read heightAboveReference. Use the output convention below.
Subtract referenceElevation from topElevation for heightAboveReference.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| topElevation | Top Elevation | Required. Finite number. |
| referenceElevation | Reference Elevation | Required. Finite number. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| heightAboveReference | Height Above Reference | Required. Finite number. |
{
"input": {
"topElevation": 112,
"referenceElevation": 100
},
"output": {
"heightAboveReference": 12
}
}Limitations and assumptions
- Both elevations must share a datum and unit; this does not determine a legally applicable zoning height reference or allowable height.
- Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.
Alternative or Complementary methods
Check the applicable survey, planning rules, and professional design assessment before using the result in a project.
References
Similar or alternative tools
- Parcel Streetwall Stepback Offset
Subtract lowerFacadeOffset from upperFacadeOffset for stepback.
- Drawing Elevation Datum Offset
Add drawingDatumAbsoluteElevation to drawingElevation for absoluteElevation.