Foundation wall code requirements

The International Building code states the following: 1806.1 General.

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. This means that retaining walls need to be engineered. The International Residential Code states the following: R404.5 Retaining walls.

Retaining walls that are not laterally supported at the top and that retain in excess of 24 inches (610 mm) of unbalanced fill 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. Again refeering that walls need engineering. Check with your local building official to see if this is applicable in your area.