The American Heritage® Dictionary of the English Language, 4th Edition
adj. Consisting of or characterized by prefabricated wall, floor, and roof sections that are shipped to and assembled at the building site: panelized housing.
adj. Split into a group of panels for convenient assembly.
Word Usage
"Modular involves nominally complete sections of the house being joined on a foundation, and panelized is a “kit-of-parts” that involves a lot more on-site contracting work."