In Fulton County, any wall over four feet needs a permit and engineered plans

https://pub-3fb81553dec8447e9f78cc13238c2c70.r2.dev/retaining-wall/what-an-engineered-retaining-wall-costs-in-cobb-county-and-what-drives-the-price.html

In Fulton County, any wall over four feet needs a permit and engineered plans. Knowing this rule protects your investment, ensures safety, avoids fines, and speeds approvals for durable, code-compliant construction.