Fire Resistive Construction (ISO)
Definition
Fire Resistive Construction (ISO) — one of six building construction categories established by Insurance Services
Office, Inc. (ISO), in its Commercial Lines Manual (CLM) for purposes
of developing rates for insuring commercial property, based on susceptibility
to damage by fire. The CLM description of fire resistive construction,
followed by the associated ISO construction code, is exterior walls, floors,
and roof of masonry or fire-resistive materials with a fire resistance rating
of at least 2 hours (Construction Code 6). The construction code indicates the
ranking of this building construction category within the six categories, with
1 as the least fire-resistive and 6 as the most fire-resistive.