The height line in 15 departments
Rules from each department's own page, read 23 October 2026.
| Building department | Permit needed when the wall… | Measured |
|---|---|---|
| Austin, TX | is over 4 feet, supports a surcharge, or is in a flood hazard area | bottom of footing to top of wall |
| Pikes Peak Regional (Colorado Springs) | is over 4 feet, or supports a surcharge from a structure or a slope steeper than 2 to 1 | "from the lower grade to the upper grade" |
| Saint Paul, MN | supports "more than 4 feet of earth" | height of earth retained |
| Bellevue, WA | is "over four feet high", or supports a surcharge load; critical-area sites may need one at any height | bottom of footing to top of wall |
| Seattle, WA | is over 4 feet ("Some retaining walls and rockeries that are not over 4 feet in height" usually need none) | bottom of footing to top of wall |
| Elk Grove, CA | is over 4 feet or supports a surcharge | bottom of footing |
| Denton, TX | is "over 4-foot" | top of wall to bottom of footing |
| Waco, TX | is over 48 inches, which also needs an engineer's design and a Foundation permit | wall height |
| Cary, NC | retains "more than 48” of fill" | bottom of footing to fill height |
| Citrus Heights, CA | retains 36 inches or more of earth (masonry) or 24 inches (wood), per its permit table; its website says 4 feet from the bottom of the footing | see text |
| Naperville, IL | is "over three feet in height", new or replacement | wall height |
| San Diego, CA | is "more than three feet above the footing", or supports a surcharge | above the footing |
| San Diego County (unincorporated) | retains over 3 feet of soil, is over 6 feet in total, or has a slope, structure within 6 feet or surcharge behind it | top of footing to top of retained soil |
| Albuquerque, NM | has more than 24 inches of grade difference between its two sides | finished grade on opposite sides |
| Cincinnati, OH | is a retaining wall: it needs a separate permit, with no exemption listed | — |
Citrus Heights publishes two different lines: its permit table exempts walls retaining less than 36 inches of earth for masonry and 24 inches for wood, and its permit-requirements page exempts walls "not over 4 feet in height as measured from the bottom of the footing". Call the city at the stricter number.
The permit record
Counts are retaining wall permits in the city's file over three years to September 2026; "usual days" is the typical time from issue to final inspection.
| City | Retaining wall permits | Usual filed value | Usual days to final |
|---|---|---|---|
| Cincinnati, OH | 245 | $15,000 | 501 |
| San Diego County (unincorporated) | 123 | $21,090 | 303 |
Both are slow, and the clock runs from issue to the final inspection. San Diego County ties walls to grading: when it issues a grading permit, "a building permit shall be obtained to cover all retaining walls, drainage structures and related items".
Surcharge: the word that ends the exemption
Pikes Peak Regional spells out what a surcharge is: a load "from a structure or a grade slope greater than two (2) units horizontal to one (1) vertical" behind the wall. Austin, Bellevue, Elk Grove and San Diego all drop the height exemption for a wall "supporting a surcharge", Pikes Peak Regional for a slope steeper than 2 to 1, and San Diego County requires level backfill with no structure within 6 feet. A 3-foot wall with a structure on top of it needs a permit in all of those. Fences on top of a wall count too in Albuquerque, which measures a garden wall on a retaining wall as one combined height; more in fence permits.
Who pulls it
The contractor or you, with an engineer above the line in several cities. Waco requires an engineer's design over 48 inches, Denton an engineer's final inspection report before the final, and Albuquerque a New Mexico Registered Structural Engineer or Architect over 24 inches. Seattle and Bellevue also regulate rockeries; Bellevue says any rockery or retaining wall over 30 inches "must not be located within any required setback".
Check it in five minutes
- Measure from the bottom of the planned footing, not the ground, to the top of the wall.
- Look at what sits behind it: a structure or a slope means a permit at almost any height.
- Find your department in the table; if you are within 6 inches of the line, call the city before you dig, and call 811 for locates.
See every Cincinnati retaining wall contractor by permits filed →
What this does not tell you
We read 15 departments' rules; grading, drainage and critical-area permits are separate. Our counts come from two jurisdictions, and walls built under a grading, pool or new-home permit are not counted as wall permits.
How we know this
Rules are quoted from the pages under Sources, read 23 October 2026. Permit counts, filed values and usual days to final come from each city's permit file over the three years ending September 2026. "Usual days" is the median from issue to final inspection; "reached a final" counts permits a year or more old.
Numbers come from City of Cincinnati building permits (residential, Residential Code of Ohio); San Diego County Planning & Development Services building permits on homes in the unincorporated county (the County's open-data permit, contractor and status-history files), data through October 17, 2026. Nobody paid to be on this page and nobody can.
Questions
- How tall can a retaining wall be without a permit?
Four feet in 9 of the 15 departments we read (Austin, Pikes Peak Regional, Saint Paul, Bellevue, Seattle, Elk Grove, Denton, Waco, Cary). Naperville, San Diego and San Diego County stop at 3 feet, Albuquerque at 24 inches of grade difference, and Cincinnati lists retaining walls as needing their own permit with no exemption.
- Where is the height measured from?
Usually the bottom of the footing to the top of the wall (Austin, Bellevue, Seattle, Elk Grove, Denton, Cary). Pikes Peak Regional measures 'from the lower grade to the upper grade', Albuquerque the difference in finished grade on the two sides, and San Diego County from the top of the footing to the top of the retained soil. The footing depth can put a wall that looks 3½ feet tall over a 4-foot line.
- Does a short wall ever need a permit?
Yes, if it holds up a load. Austin, Bellevue, Elk Grove and San Diego drop the exemption for a wall 'supporting a surcharge', such as a structure or a slope above it. Pikes Peak Regional also excludes walls under a slope steeper than 2 to 1, and Bellevue says critical-area sites 'may require a permit regardless of retaining wall height'.
- Do I need an engineer for a retaining wall?
Over the permit line, often. Waco requires an engineer's design for walls over 48 inches, Denton an engineer's final inspection report before the final, and Albuquerque certification by a New Mexico Registered Structural Engineer or Architect for walls over 24 inches.
- How long does a retaining wall permit take?
Long. The usual retaining wall permit reached its final inspection in 303 days in unincorporated San Diego County and 501 in Cincinnati, where 74.9% of those a year or more old reached a final.
Build your own list
Every firm with that kind of permit on record. Pick what you value. The list moves.
Related guides
- Henderson building permit search: how to look up permits on an address
- Home improvement costs in Cincinnati, OH (2026): what 8 kinds of jobs were filed at
- Do I need a permit to build a house? Yes. What 12 departments ask for, and how long it takes
- Can an unpermitted ADU be legalized? California's AB 2533 rule, and what it costs and takes
- Do I need a roofing permit in San Antonio? Yes for every re-roof: the $28.75 fee and 11,516 permits
- Do I need a permit for a home battery in unincorporated San Diego County? The online AES permit, fees and finals
For one city
- Work Exempt from Building Permits — City of Austin Development Services (accessed 2026-10-23)
- Permit Not Required — Pikes Peak Regional Building Department (accessed 2026-10-23)
- When is a permit required? — City of Saint Paul DSI (accessed 2026-10-23)
- Guide to Building Permits (rev. 10/31/2022) — City of Naperville, IL (accessed 2026-10-23)
- Projects Requiring a Building Permit (CHB0600, rev. 08/23) — City of Citrus Heights, CA (accessed 2026-10-23)
- Permit Requirements & Exemptions — City of Citrus Heights, CA (accessed 2026-10-23)
- When is a Permit Required? — City of San Diego Development Services (accessed 2026-10-23)
- PDS 110 Building Permit Requirements per Adoptive Ordinance (rev. 01/01/2026) — County of San Diego (accessed 2026-10-23)
- Work requiring permits — City of Bellevue, WA (accessed 2026-10-23)
- Do You Need a Permit? — Seattle SDCI (accessed 2026-10-23)
- Do I need a building permit? — City of Elk Grove, CA (accessed 2026-10-23)
- Retaining Walls — City of Denton, TX (accessed 2026-10-23)
- Do I Need a Permit? — City of Waco Inspection Services (accessed 2026-10-23)
- Residential Permits FAQ — Town of Cary, NC (accessed 2026-10-23)
- Home Owner's Building Permit Guide — City of Albuquerque Building Safety Division (accessed 2026-10-23)
- Residential Permit Guide — City of Cincinnati Buildings & Inspections (accessed 2026-10-23)