A poured concrete wall should be at least 4 inches thick. A thicker wall will provide more insulation and is recommended in colder climates.

The thickness of a poured concrete wall will vary depending on the type of wall, the climate, and the materials used. A general guideline is to have a minimum thickness of 8 inches for a poured concrete wall. However, in colder climates, it is recommended to have a thicker wall in order to prevent moisture from seeping into the walls and causing damage. In hot climates, a thinner wall may be preferable in order to help keep the building cooler.