The simplest wall typology from a geometry standpoint was the flat wall. The frames and inserts were arranged in two straight parallel rows with a constant distance between them. The distance determined the wall thickness for any particular row. Continuous #3 (3/8 inches in diameter) steel reinforcement bars were placed inside the wall – both vertically and horizontally – prior to the concrete cast. The subsequent rows of frames and inserts were lined up with the ones below to obtain a constant thickness along the height of the wall. The flexibility of the system allowed for variation in the distance between molds at every cast row, making the construction of a tapered wall possible. The actual geometry of the inserts determines the finish of the flat surface. In this prototype, simple flat urethane rubber inserts were used giving the overall wall a flat surface. An intrinsic characteristic of the system is the presence of seams where the inserts meet.