Building construction types are explained in the current building code adopted by the jurisdiction of question. Where NFPA 220 Table E is similar to the IBC which is adopted in many areas, I would advise that assigning building types in a specific area be in accordance with the local building code. ( if your jurisdiction has adopted the NEC there is no guarantee that the building enforcement branch has adopted table E of NFPA 220).
Type I and II structures in general do not have any wood framing members, with the degree of flammable interior determine the degrees of each type.
As mentioned Type III is generally a masonry envelope with standard 2 X, 6, 8, Construction
Type IV is Mill Construction Stone or masonry exterior with Heavy timber interior (Plank floors etc.)
Type V is a typical (for the NE anyway)wood frame dwelling.
Charlie
[This message has been edited by cpal (edited 03-10-2005).]
