Tacoma, WA Fence Regulations: Retaining Walls (2026)
Key Facts
- Permit-exempt height
- 4 feet or less
- Measured
- Footing bottom to wall top
- Exemption lost if
- Wall supports a surcharge
- Fence-on-wall
- Counts as a surcharge
- Governing section
- TMC § 2.02.090, item 4
Summary
Tacoma exempts retaining walls up to 4 feet high from a building permit, unless the wall supports a surcharge or holds back hazardous liquids, which triggers the permit regardless of height.
Retaining walls which are not over four feet (1219 mm) 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 III-A liquids. A Fence supported by a retaining wall shall be considered a surcharge.
5. Water tanks supported directly on grade if the capacity is not greater than 5,000 gallons (18,925 L) and the ratio of height to diameter or width is not greater than 2:1.
6. Sidewalks and driveways not more than 30 inches (762 mm) above adjacent grade and on grade concrete patios with a cumulative impact not exceeding 2,000 Sq. Ft. (185.81 sq-M), provided they are not over any basement or story below and are not part of an accessible route.
7. Painting, papering, tiling, carpeting, cabinets, counter tops, and similar finish work.
8. Temporary motion picture, television, and theater stage sets and scenery.
9. Prefabricated swimming pools accessory to a Group R-3 occupancy, as applicable in Section 101.2, which are less than 24 inches (610 mm) deep, are not greater than 5,000 gallons (18,925 L), and are installed entirely above ground.
10. Shade cloth structures constructed for nursery or agricultural purposes, not including service systems.
11. Swings and other playground equipment accessory to detached one-and two-family dwellings.
12.
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: rev 4946110; v22 updated 2026-07-28).
Full Breakdown
TMC § 2.02.090 exempts retaining walls from the City's building permit requirement only if they're 4 feet or less, measured from the bottom of the footing to the top of the wall, and aren't supporting a surcharge or impounding Class I, II, or III-A liquids. The code specifically calls out that a fence sitting on top of a retaining wall counts as a surcharge, so a short wall topped by a fence can lose its exemption. Any retaining wall over 4 feet, or a shorter wall carrying a surcharge, needs a City of Tacoma building permit, which typically means engineered plans for structural adequacy.
Violations & Fines
Building or expanding a retaining wall past the 4-foot exemption without a permit is a code violation; an unpermitted wall that fails can also expose the owner to liability for resulting damage.
Frequently Asked Questions
How tall can a retaining wall be in Tacoma without a permit?
Does putting a fence on top of a retaining wall change the permit rule?
Sources & Official References
Other rules in Tacoma
Compare Tacoma to another location·View the Washington fence regulations overview
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Retaining Walls in Nearby Cities
How other cities in this county handle retaining walls.