A Different Construction Process Modular IS THE WAVE OF THE FUTURE… Modular Building Systems is a method of construction, not a building type. It greatly differs from temporary buildings, such as construction trailers or mobile homes. “Modular custom-designed commercial buildings are just like their site-built counterparts. Using modular does not change the design, structural system, or finish materials options available to the owner and architect. The only difference is in the method of construction.” After the design is finalized with an architect, construction plans are sent to a factory where the majority of the building is erected.