True modular homes or sometimes referred to as “custom” or “system-built” homes are built using an engineered approach to produce structures in a more efficient and cost effective method. Instead of the old-fashioned construction method, (stick-built) most of the work is pre-fabricated at an off-site climate controlled factory. As each sub-section or modular unit is finished it is transported to the building site on a flat bed truck with no steel undercarriage supporting the floor system. Once on site each modular unit is constructed together using the same methods that stick-built homes use.
Many people, when they hear the term "modular", automatically think “manufactured home” or “on-frame modular home”. A, “True Modular” home is neither. True modular homes have all of the characteristics of stick-built homes and must pass the same code requirements as stick-built homes. True modular homes have more flexibility as compared to on-frame modular homes, which I will discus later. Another difference is - true modular homes don’t have a steel undercarriage supporting the floor system like on-frame modular homes or HUD-code manufactured homes. True modular homes are custom-built homes constructed in a controlled environment and transported to job site 90% to 95% completed. A true modular home can be an entry-level single-story home or a multi-million dollar mansion consisting of 8,000 sq. ft. or more with multiple levels. Many apartment and townhome building projects utilize true modular construction techniques today.
MODULAR
HOME RESOURCES 
True modular homes or sometimes referred to as “custom” or “system-built” homes are built using an engineered approach to produce structures in a more efficient and cost effective method. Instead of the old-fashioned construction method, (stick-built) most of the work is pre-fabricated at an off-site climate controlled factory. As each sub-section or modular unit is finished it is transported to the building site on a flat bed truck with no steel undercarriage supporting the floor system. Once on site each modular unit is constructed together using the same methods that stick-built homes use.