Systems and methods for providing reinforced insulating stem walls are disclosed herein. Some implementations of the systems and methods include one or more stem wall assemblies. In some cases, the stem wall assembly has one or more first panels, one or more second panels, and one or more couplers. In some cases, the first panel is configured to be joined to the second panel by the coupler such that the first panel is separated from the second panel by a core cavity, which, in some cases, is configured to be filled with a filler material to form a core that becomes integral with the stem wall assembly. Other implementations are also described.

The invention relates to a method for designing and forming a retaining wall in the ground having a required target wall stiffness made of a soil-based mortar, which is produced in the ground by mixing soil material and a cement suspension, and vertically aligned support beams, which are positioned in the soil-based mortar and arranged therein, wherein the arrangement of the support beams is laid-out to have an overall beam stiffness. According to the invention, it is provided that the support beams are arranged such that the laid-out overall beam stiffness is less than the required target wall stiffness, and that, when laying-out and arranging the support beams, an additional stiffness component is added that results from at least one adjacent wall section made of soil-based mortar.