Sumner County, TN Fence Regulations: Retaining Walls (2026)
Key Facts
- Engineering plan required
- Retaining walls over 4 ft
- Sealed by
- Tennessee-licensed Professional Engineer
- Allowed materials
- Stone, concrete, inorganic material
- Banned material
- Wood, including railroad crossties
- Added standards from
- Sumner County Engineer
- Applies to
- Unincorporated Sumner County only
Summary
Any retaining wall over 4 feet tall in unincorporated Sumner County needs engineered plans sealed by a Tennessee professional engineer before it can go up. Walls must be built from durable stone, concrete, or other inorganic material: wood, including railroad crossties, is banned outright, and the County Engineer maintains added technical requirements.
13. Plans for all retaining walls over four (4) feet in height shall be designed and sealed by a Tennessee Professional Engineer. Retaining walls shall be constructed of durable stone, concrete, or other inorganic, non-decomposable materials. Wooden materials, to include railroad crossties, are prohibited. The County Engineer shall promulgate and maintain a set of additional requirements for retaining walls.
C. Permitted Obstructions in Required Yards
In all districts, the following shall not be considered obstructions when located within a required yard except these items shall comply with the above provisions of this subsection.
1. In any required yard:
a. Arbors and Trellises.
b. Awnings or canopies projecting from a building wall over a window or door into the required yard not more than six (6) feet and having no supports other than provided by the wall or its integral parts.
c. Gutters or downspouts projecting into or over required yards not more than twenty-four (24) inches
d. Open fire escapes or staircase, the riser of which shall be at least fifty (50) percent open and whose vertical projection downward into a required yard does not project more than three (3) feet into, and not exceeding ten (10) percent of the area of the required yard
Full Breakdown
Section 1101, Subsection B(13) of the Zoning Resolution sets the threshold at 4 feet: any retaining wall taller than that must have plans designed and sealed by a Tennessee-licensed Professional Engineer before a permit is issued, shifting the burden of proving structural adequacy onto a design professional rather than the homeowner or contractor. The same subsection restricts allowable materials to durable stone, concrete, or other inorganic, non-decomposable material, and it names wooden materials, including railroad crossties, a common do-it-yourself retaining wall material, as expressly prohibited regardless of height.
Beyond the height and material rules written into the Resolution itself, Subsection B(13) delegates ongoing technical detail to the County Engineer, who "shall promulgate and maintain a set of additional requirements for retaining walls," meaning a builder needs to check the Engineer's current standards, not just the Resolution's text, before finalizing a design. Retaining walls also remain subject to the general fence and wall provisions of Section 1101, Subsection B, including the requirement that support structures not face the street and that walls stay out of utility and drainage easements absent written provider consent under Subsection B(11).
A retaining wall used as a screening structure in a required buffer yard carries an additional duty to stay structurally sound under the landscaping maintenance standard in Section 1104.
Violations & Fines
An unengineered retaining wall over 4 feet, or one built from prohibited wood or railroad-tie material, violates Section 1101 of the Zoning Resolution. The Director of Building Codes can require repair, replacement, or removal, and Section 1413, Subsection D makes continued noncompliance a misdemeanor with a fine plus costs, with each day counted as a separate offense.
Frequently Asked Questions
Do I need an engineer for a retaining wall in Sumner County?
Can I use railroad crossties for a retaining wall?
Are there more retaining wall rules beyond the Zoning Resolution?
Sources & Official References
Other rules in Sumner County
Compare Sumner County to another location·View the Tennessee fence regulations overview
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