Note, however, that most jurisdictions require permits and engineering drawings for all retaining walls over 3 to 4 feet in height, especially if the soil behind them supports a surcharge (a load ...

Some local codes may also demand permits for retaining walls that support a vertical load on top of the soil behind them ...

For instance, a study demonstrated that various densities and thicknesses of EPS geofoam effectively minimized lateral earth pressure on rigid retaining walls subjected to surcharge loading ...