Economical yet custom designed concrete homes have been built for low-income families in the Arkansas Valley by Cheraw, Colorado contractor-developer, Barton Ewers, for 10 to 11 dollars per square foot, complete with floor coverings. Ewers has built more than 250 of the houses, each requiring 18 man-days to construct the exterior and partition walls for the average 1,500 square foot house. Complete flexibility of floor plans is possible, with the dwelling size depending upon the needs of the owner or tenant. In all of his structures, Ewers combines a concrete slab on grade, cast-in-place concrete walls, and prefabricated wood truss roofs. The lightweight, dry-packed concrete walls are finished both on interior and exterior surfaces with portland cement plaster. The key to Ewer's system is a unique, self-designed slipform, expandable from 4 inches for interior walls to 6 inches for outside walls. For the walls, the dry-packed concrete is proportioned 1 part portland cement to 6 parts aggregate by volume. The aggregate consists of equal parts of fine and coarse lava rock: one-half part fines to three-eighths of an inch; and the other half, three-eighths to five-eights of an inch. Water is proportioned to aggregate in the ratio of 1 part to 6, by volume. For reinforcing, Ewers uses a heavy-gage double-strand barbed wire, preferably already used because it has been elongated and is able to immediately pick up any tensile stresses which may develop within the wall. If new barbed wire must be used, it is stretched to the breaking point before being placed in the wall. The burrs on the barbed wire provide greater bond than the more customary one-fourth of an inch pencil rod. The barbed wire is set at 10 inch heights, then bent up every 3 feet for vertical reinforcement action.