The height question has three parts: which sign category applies, where the measurement starts, and what counts as the top. Write all three on the elevation drawing. A cabinet dimension by itself cannot tell a reviewer how tall the completed sign will be.
Find the category before choosing a number
Describe the structure: solid base or exposed supports, face dimensions, overall height, number of faces, illumination, and any electronic display. Match that description to the adopted definitions and the parcel’s zoning and overlays. A vendor calling a product a “monument” does not make it one under the code. The monument-sign definition guide explains the classification questions.
Collect the height provision, measurement definition, and conditions that change the allowance. Check whether an approved development or sign plan applies. Record sign type and district beside each rule; a height for another freestanding sign category is not evidence for this design.
Put elevations on the drawing
Use a common reference for the ground, the road if relevant, and the top. Ask which starting elevation the applicable definition requires: existing grade, finished grade, an average, or a road reference. Ask how it treats a raised planter or mound. These are alternatives to investigate, not interchangeable methods.
| Drawing label | What to establish |
|---|---|
| Reference elevation | Code-defined starting point and its source |
| Existing and finished grade | Both sides of the sign, with planned grading |
| Base and cabinet | Separate dimensions plus the assembled total |
| Highest feature | Cap, ornament, letters, or another element that may count |
| Reported height | Top elevation minus applicable reference elevation |
Two real codes, two starting points
San Luis Obispo, California measures from the ground at the sign. Its section 15.40.470 says “The maximum height of a monument sign is six feet from the average natural grade at the base of the sign,” with a four-foot limit in the C-R and C-D zones. The word “natural” matters: read plainly, a berm built up under the sign would not raise the starting point. Confirm that reading with the city before you design around it.
Austin, Texas, in its expressway corridor sign district, offers two starting points and takes the more generous one. Under section 25-10-123(B)(3), “The sign height may not exceed the greater of: (a) 35 feet above frontage street pavement grade; or (b) 20 feet above grade at the base of the sign.” On a lot that sits below the road, the road-based number wins; on a lot above it, the base-based one does. (Both read September 28, 2026.)
Neither choice is yours to make. The code names the starting point, and the drawing should show it.
Fictional example: the road is above the site
All elevations and the limit below are hypothetical. Imagine a road reference at elevation 102 feet and finished ground at the sign at elevation 100 feet. Assume the fictional rule allows 8 feet above that road reference and includes the decorative cap.
Maximum top elevation = 102 + 8 = 110 feet. From the sign’s ground, that leaves 110 − 100 = 10 feet for the complete above-ground structure. If the fictional rule instead started at finished grade, the top would be 100 + 8 = 108 feet, leaving 8 feet above ground.
This illustrates subtraction, not an entitlement to build a taller sign on a low site. Do not select the more favorable reference yourself. Confirm the definition and any grading restrictions. On a slope, submit the required reference points rather than inventing an average.
Test the whole assembly
In a second fictional example, a 2-foot base, 5-foot cabinet, and 1-foot cap total 8 feet. Calling it a “5-foot sign” describes the cabinet and conceals the overall height. Dimension the visible assembly and show which parts the rule counts. Keep footing depth separate from the above-ground calculation.
Check setback and visibility independently. If the actual ordinance links height to location, draw each candidate location and calculate its allowance separately. A sign can satisfy its height limit while obstructing a required sight area.
Before releasing the drawing
- Confirm the parcel, sign category, district, overlays, and site approvals.
- Keep the current height provision and measurement definition in the project record.
- Label the datum, grade changes, highest point, and calculation on the elevation.
- Resolve uncertain decorative features or slope treatment in writing.
- Have the designer establish structural requirements separately; this worksheet does not size foundations, supports, or connections.
The deliverable is a reproducible dimension: another person should be able to locate the starting point, locate the top, and obtain the same height from the drawing. This guide supplies a measurement workflow; project limits come from the applicable adopted documents.