Nassau County, FL Fence Regulations: Retaining Walls (2026)
Key Facts
- Permit-free height
- 4 ft max, footing to top of wall
- Surcharge exception
- Any surcharge-supporting wall needs a permit
- Liquid exception
- Walls impounding Class I/II/IIIA liquids need permit
- Design requirement
- Engineer-sealed plans once threshold is crossed
- Governing code
- Nassau County Code § 7-6 (FBC § 105.2)
- Enforcing agency
- Nassau County Building Department
Summary
In unincorporated Nassau County, retaining walls up to 4 feet tall, measured from the bottom of the footing to the top of the wall, are exempt from a building permit under Section 105.2 of the adopted Florida Building Code. Taller walls, or any wall holding back a surcharge or Class I, II or IIIA liquids, need a permit and engineered plans.
105.2 Work exempt from permit. ... Permits shall not be required for the following: ... 4.Retaining walls that are not over 4 feet in height measured from the bottom of the footing to the top of the wall, unless supporting a surcharge or impounding Class I, II or IIIA liquids.
Full Breakdown
2's list of permit-exempt work sets the retaining-wall threshold in item 4: a wall counts as exempt only if it measures 4 feet or less "from the bottom of the footing to the top of the wall," a stricter measuring point than simply the exposed face height, so a wall with a deep footing can trip the threshold even if it looks shorter than 4 feet above grade. The exemption also has a functional carve-out: any retaining wall that supports a surcharge, meaning it holds back additional load such as a driveway, parking area or sloped fill above the wall, or that impounds Class I, II or IIIA flammable or combustible liquids, needs a permit no matter its height.
1, and because a retaining wall is a structural element, the plans generally must be prepared and sealed by a Florida-registered engineer under Chapter 471, Florida Statutes, rather than approved on a homeowner's sketch. 6, apply to a permitted retaining wall. Homeowners retaining a contractor for a wall near this size should ask early whether the wall's total footing-to-top height, not just its visible face, keeps it under the 4-foot exemption.
Violations & Fines
Building an unpermitted retaining wall over the 4-foot threshold, or one that holds back a surcharge, is treated the same as any other unpermitted structural work under Section 105.1: the Building Department can order a stop to construction and assess an increased permit fee under the adopted fee schedule once the violation is discovered, and the wall must still pass the structural plan review it would have needed originally.
Frequently Asked Questions
How tall can a retaining wall be in unincorporated Nassau County without a permit?
Does a retaining wall that holds up a driveway need a permit even if it's under 4 feet?
Who has to seal the plans for a permitted retaining wall?
Sources & Official References
Other rules in Nassau County
Florida rules heatmap·Compare Nassau County to another location·View the Florida fence regulations overview
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