This section mentions structural units, structural spans, structural patterns, and lateral stability. Structural units keeps a building organized and is the building block for the structural system. A structural unit is able to be formed from columns, beam, slab, and load bearing wall and can make space for habitation. Horizontal spans can be concrete slabs or grinders, beams, and joints. Load bearing walls or framework of columns and beams can be used for the vertical support. Structural spans is about the relationship between the span and spacing which influences the dimensions and scale of spaces. Structural patterns is about grid lines and critical points which help to indicate columns or load bearing walls. Lateral stability is about a building being made stable enough so that it can not be effected by any conditions.