This U.S. industry comprises establishments primarily engaged in manufacturing prefabricated wood buildings and wood sections and panels for prefabricated wood buildings. Cross-References. Establishments primarily engaged in-- ? Fabricating wood buildings or wood sections and panels for buildings at the construction site--are classified in Sector 23, Construction; and ? Making manufactured homes (i.e., mobile homes)--are classified in U.S. Industry 321991, Manufactured Home (Mobile Home) Manufacturing.