Modular and Panelized Construction Research Thrust

Beyond conventional site-built construction, the housing industry also benefits from factory-built approach to address the need for quicker home construction. Three of the major types of factory-built components or whole unit products are panelized, modular, and manufactured homes. Panelized construction refers to factory-manufactured components, such as walls and floor panels; modular construction involves the prefabrication of volumetric sections of a building; and manufactured housing is entirely factory built.

In modular construction, one or more sections are built in the factory and shipped to the site. Modular homes are supported on a permanent foundation like site-built homes. Manufactured homes that are completely prefabricated and are transported in most cases on their wheels do not require a permanent foundation, but all sections must be built on a permanent chassis that remains with the building at the site. While panelized and modular construction must be designed based on state, local, or regional building codes, manufactured homes are mainly governed by the Federal Manufactured Home Construction and Safety Standards, known as HUD Code, which regulate strength, durability, transportability, fire resistance, energy efficiency, and quality, as well as performance standards for heating, plumbing, air conditioning, thermal and electrical systems. Modular homes are normally built in multiple sections and attached to one another once placed on the foundation. These homes can be two- to three-story homes. Panelized homes are assembled using prefabricated panels built in the factory, most having exterior sheathing and interior gypsum/drywall and some including windows, doors, wiring, and siding. Modular construction is of particular interest for application to multi-story residential buildings. There is also some development in the area of temporary housing that is used in post natural disaster situations. Such temporary units, however, are not necessarily built to standards for permanent manufactured units for prolonged use.