Retaining Walls

Printable Handout for Retaining Walls

Permit and Fees

If the retaining wall is less than 4 feet in height then no permit is required. Fees are based on valuation of project according to the Building Value Range exhibit of the Fee schedule. Retaining walls 4 feet in height or greater require a building permit.

Specific Requirements

Engineering is required on walls greater than 4 feet in height. An engineered product installed as per the manufacturer's installation instructions does not require additional engineering.

A site plan of the property is required indicating where the wall will be placed on the property.

A final inspection is required once the wall is complete. Provide pictures of the wall showing tie back systems and anchoring of wall during construction at the final inspection.

Code Requirements

IBC 1610.2 Retaining walls shall be designed to ensure stability against overturning, sliding, excessive foundation pressure and water uplift. Retaining walls shall be designed for a safety factor of 1.5 against lateral sliding and overturning.

IRC 404.1.3 A design in accordance with accepted engineering practice shall be provided for concrete or masonry foundation walls when any of the following conditions exist:

  • Walls are subject to hydrostatic pressure from ground water.
  • Walls supporting more than 48 inches of unbalanced backfill (dirt on one side of the wall and not on the other, or walls more than 48” high) that do not have permanent lateral support at the top and bottom.

Zoning Requirements

Final grades in all developments shall not exceed a 4:1 ratio unless the City has approved plans for retaining walls, terraces or similar controls.

Retaining walls are not allowed within city drainage and utility easements.

Excavation or placement of an earth material in an amount equal to or greater than 50 cubic yards requires a grading permit and a grading plan.

Additional standards apply to retaining walls located in the Mississippi River Critical Corridor. Contact the Planning Department for more information regarding those standards at 651-322-2051.