Description
Calculate a planning height relative to a supplied ground datum.
Planning measurements depend on lot boundaries, excluded area, frontage, ground datum and the unit or person being served. A footprint fraction and a width margin answer different geometric questions. Accessibility, easement rights and zoning compliance depend on verified conditions and applicable requirements beyond a supplied flag or numerical comparison.
Calculate a planning height relative to a supplied ground datum.
When to use this tool
Use Planning Height Ground Datum Difference when you already have suppliedGroundDatumElevation, recordedTopElevation and need to calculate a planning height relative to a supplied ground datum.
How to use the tool and how it works
- Enter suppliedGroundDatumElevation, recordedTopElevation. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read signedGap. Use the output convention below.
Return recordedTopElevation-suppliedGroundDatumElevation using matching units and vertical reference.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| suppliedGroundDatumElevation | Supplied Ground Datum Elevation | Required. Finite number. |
| recordedTopElevation | Recorded Top Elevation | Required. Finite number. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| signedGap | Signed Gap | Required. Finite number. |
{
"input": {
"suppliedGroundDatumElevation": 12,
"recordedTopElevation": 17
},
"output": {
"signedGap": 5
}
}Limitations and assumptions
- A signed difference does not establish a legal building height, correct survey datum or permit compliance.
- 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
Use a verified survey, route inspection and the applicable planning definitions for actual coverage, access or height questions. Separate a supplied geometric margin from the documentation needed to establish an easement or accessibility condition.
References
Similar or alternative tools
- Public Space Frontage Per Unit
Calculate public-space frontage per supplied unit.
- Parcel Access Easement Width Margin
Compare an easement width with a supplied required width.