A building permit is required for any retaining wall over 3 ft in height (measured from the non-retained grade), over 2 ft if it supports a surcharge load, located closer than its height to a property line, or with a fence/guardrail on top exceeding 6 ft total.
Under §1115.105.2 (Work Exempt from Permit), the four permit triggers are: (1) wall height >3 ft, (2) height >2 ft with surcharge (driveway, pool, structure), (3) distance to property line ≤ wall height, or (4) combined wall + fence height >6 ft. Walls within the public road right-of-way require a Special Use Permit from Highways & Traffic. All walls must be kept structurally sound.
Stop-work order; up to $1,000 fine; engineer-sealed plans required to remediate.
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