A monument sign sits on a solid base at ground level. Pole and pylon signs stand on exposed supports that hold the face up off the ground. A pole can be wrapped in a cover that looks like a solid base, so classify the structure, not the wrapper.
The ISA glossary gives the industry meaning of these words. The local code decides which category your sign falls in and what that category allows.
How one real code handles it
San Luis Obispo, California describes monument signs as having “a solid base that the sign face is installed upon” and then gives the two forms very different ceilings in section 15.40.470:
“The maximum height of a monument sign is six feet from the average natural grade at the base of the sign.”
“Pole signs may have a maximum height of sixteen feet and a maximum area of seventy-two square feet measured from the average natural grade of the ground immediately beneath the sign.”
In the city's C-R and C-D zones the monument ceiling drops to four feet. Pole signs come with their own condition: one per premises, along an arterial street frontage. So depending on its category and site, the same cabinet could be allowed at 16 feet on poles or capped at 6 feet, or 4, on a base. Getting the category right is the first number on the job, not a label you settle later. (Section history: Ord. 1667, 2019. We read it on September 28, 2026.)
What to check on your job
- Does the code separate monument, pole and pylon forms, or lump them into one freestanding category?
- What decides the category: base width, exposed supports, height, or something else?
- Which district rules apply once the category is settled?
Put the cabinet, base, supports, existing grade and total height on one elevation drawing and get the category confirmed before you pick a height limit. The classification guide covers unfamiliar terms.