If we think a little about the cost of residential units, we find that the cost of the structural structure is 4050% of the total cost of the construction phase of the residential unit. This high ratio makes it possible to study economic alternatives in the construction process as necessary and inevitable to reduce the cost of housing in general. Since most projects are constructed with the frame system, it has been taken as the reference system and compared to the cast in situ load-bearing walls system and the precast autoclaved aerated concrete panels system (AAC). The comparison was based on the cost, time of construction, and thermal insulation capacity. As thus, it was found that the cast in situ bearing wall system and the precast panel system is much more suitable in house massing projects.