The IBC lists five types of construction ranging from Type I (Fire-Resistive) through Type V (Wood Frame). Initially most modular structures were typically simple wood framed buildings that would be classified as Type V, but today you can find modular structures across all five construction types from wood and heavy timber to Type I fire-resistive structures constructed of steel and concrete. The materials used are only limited by physics and our imaginations.

The primary use of a modular structure, also known as the “occupancy classification,” can be any of the listed classifications. From Residential and Institutional to Educational and Industrial. The building codes do not limit the use of modular construction to specific classifications. In fact, you will not find a reference to modular construction in the basic building codes as it is a method of construction.

Modular construction is a method of building structures in a factory or “offsite,” that are then transported to the site where they are lifted into place and secured together. Most require some level of final finish on site, but some are delivered in nearly ready to use condition. Modular structures may be used to complete the entire structure or a component such as the repetitive units of an apartment building, an elevator shaft, or the bathrooms of a high-rise building.

Regardless of the use or material, a modular structure must be built to the same high standards set by the building code as your local site-built products and engineered to meet the rigorous requirements of transportation and set. It has been said that when you transport and set a modular structure you must engineer it as if they were going to be exposed to a hurricane and earthquake for the entire journey from the factory to the site. ICC NTA offers modular construction solutions including inspections, plan reviews, and engineering.