Peoria, IL Fence Regulations: Retaining Walls (2026)

Section 3.5.7.A.9 of the Unified Development Code lists retaining walls among the structures allowed in required yards without being treated as prohibited obstructions, but only 'subject to applicable height restrictions of 5.4,' the same chapter that governs fences and walls. Section 10.0 defines a retaining wall as a wall designed to resist the lateral displacement of soil or other material, and it adds a design rule with real teeth: the wall top must follow an established grade and cannot protrude above the established grade, so a retaining wall cannot be built taller than the slope it retains just to gain extra screening height.

Section 5.4.6.C sets the numeric limits that apply. In Residential, Office, Commercial, Institutional and I-1 districts, a wall in the front or corner side yard tops out at 3 feet, while a side or rear yard wall can reach 6 feet, with no fence or wall permitted within 3 feet of a principal structure. In the I-2 and I-3 Industrial Districts, the front and corner side yard cap rises to 8 feet, with a 10-foot setback required once a corner side yard wall in I-2/I-3 exceeds 6 feet, and side and rear yard walls in those districts also cap at 8 feet. Height is measured from established grade to the top of the wall under Section 5.4.6.B.2, and where the grade forms a contour, the wall must follow that same contour rather than stepping up to a flat top. Pillars built into a retaining wall cannot exceed the wall height by more than 25 percent under 5.4.6.B.3.