On a sloped lot, or where two lots sit at different grades, a retaining wall is often part of a fence or wall project. It is also one of the easiest wall projects to under-budget, because the parts that keep a wall standing are the parts you cannot see. This guide gives dated planning ranges, explains what moves the price, and shows where St. George's permit rule kicks in.
A note on the numbers: no St. George wall company publishes retaining wall prices, so the figures below are national ranges from HomeGuide (updated January 16, 2026), cross-checked against Angi (updated September 15, 2026). They are for planning, not quotes.
Retaining wall cost by height
Height is the biggest single driver. HomeGuide prices a 10-foot-long wall at three heights:
| Type | Typical installed range (total for 10 linear feet) | What to know |
|---|---|---|
| 2 feet tall | $700–$1,300 | Usually below permit and engineering thresholds. |
| 4 feet tall | $1,400–$2,600 | St. George permit threshold (City Code §10-18-5). |
| 6 feet tall | $2,100–$3,900 | Engineering and a permit are likely. |
HomeGuide also notes that most retaining wall contractors have a project minimum of about $1,500–$3,000, so a short garden wall may cost more per foot than the table suggests.
Cost per square foot by material
| Type | Typical installed range (per square foot of wall) | What to know |
|---|---|---|
| Concrete block (CMU) | $15–$40 | Mortared, reinforced block on a footing. |
| Poured concrete | $20–$45 | Formwork, steel, and engineering raise the price. |
| Natural stone | $20–$95 | Wide range: stacked stone to large boulders. |
| Timber | $15–$30 | Low cost but the shortest life; not for tall or loaded walls. |
Cost per square foot by wall type
| Type | Typical installed range (per square foot of wall) | What to know |
|---|---|---|
| Segmental (interlocking block) | $15–$35 | Dry-stacked units; drainage and base are part of the job. |
| Gravity wall | $20–$50 | Relies on its own weight; common for lower walls. |
| Cantilevered wall | $40–$80 | Reinforced concrete or CMU on a footing; taller walls. |
HomeGuide's overall average, including materials and labor, is $35–$65 per square foot. Angi puts the national average project at $6,085 (typical range $3,192–$9,208).
What drives the price on a St. George lot
Extra costs to ask about
| Type | Typical installed range (price and unit) | What to know |
|---|---|---|
| Structural engineering | $500–$2,000+ | HomeGuide; Angi lists $350–$750 for a structural engineer. |
| Permit | $50–$450 | Varies by city and wall size (HomeGuide, Angi). |
| French drain | $10–$85+ per linear ft | Drainage behind the wall. |
| Footings | $18–$55 per linear ft | Deeper and wider as the wall gets taller. |
| Old wall demolition | $15–$30 per linear ft | Plus disposal fees. |
The St. George permit rule for retaining walls
St. George City Code §10-18-5. Rockery, segmental block, reinforced concrete, or CMU retaining walls four feet or greater in height need a city permit, and so does any fence or retaining wall in a front setback, unless shown in detail on an approved site development plan.
How height is measured. Concrete and CMU walls: top of footing to top of wall. Rockery and segmental block walls: exposed face to finished grade next to the base of the wall.
The application needs a site plan and, for retaining walls, a landscape and drainage plan. The permit guide walks through the steps and where to apply.
Neighboring cities set their own triggers
If your property is outside St. George city limits, a different code applies, and several set engineering or permit triggers of their own. For example, Santa Clara requires a building permit and engineered design for a retaining wall over 4 feet measured from the bottom of the footing, and Washington City requires a Public Works permit and engineering analysis for rockery walls 3 feet or taller. Check the service area guide for your city.
How to compare retaining wall quotes
- Get the height, length, wall type, and block or material named in writing, measured the way your city measures it.
- Ask whether engineering, the permit, the drainage plan, and inspections are in the price.
- Ask what goes behind the wall: gravel backfill, drain pipe, fabric, and where the water exits.
- Ask how deep the footing or base will be and what happens if they hit rock.
- Confirm the company's Utah license status with DOPL and ask for proof of insurance. See the license guide.
Sources: HomeGuide, "Retaining Wall Cost" (updated January 16, 2026); Angi, "Retaining Wall Cost" (updated September 15, 2026); St. George City Code §10-18-5 (checked September 26, 2026). Full source list on the cost guide.