This class will review the development of Type III construction over the past 200 years, including how recent changes in the building code now permit much larger amounts of wood in these structures. It will review all of the elements of "ordinary construction" and their related firefighting challenges. Contrasts will be drawn between older legacy "Main Street" structures and the new versions of Type III construction. Emphasis will be placed on the new hazards of changes in wall assemblies and floor systems.