What does 'Modular Building' mean exactly?
Per the Modular Building Institute, the foremost resource on the topic, “Modular Building is a process in which a building is constructed off-site, under controlled plant conditions, using the same materials and designing to the same codes and standards as conventionally built facilities – but in about half the time." Modular Building is also a bit of an umbrella term that includes a couple of different types of construction:
Volumetric Modular Building (preferred by the Modular Building Institute) is a process in which entire rooms or sections of rooms—complete with walls, floors, and ceilings—are built in a factory setting and then transported to a final site for assembly. This type of construction is used for both permanent and relocatable modular projects (buildings that aren’t designed to be moved versus those that are; think a hotel versus a temporary classroom).
Panelized construction is a process in which interior and/or exterior wall panels are built in a factory setting and then transported to and arranged on the building site. The rest of the building is constructed on-site.