The provisions of this code are not intended to
prevent the installation of any material or to prohibit any
method of construction not specifically prescribed by this
code, provided that any such alternative has been approved.
An alternative material or method of construction shall be
approved where the code official finds that the proposed
design is satisfactory and complies with the intent of the provisions
of this code, and that the material, method or work
offered is, for the purpose intended, not less than the equivalent
of that prescribed in this code in quality, strength, effectiveness, fire resistance, durability and safety. Where the
alternative material, design or method of construction is not
approved, the code official shall respond in writing, stating
the reasons the alternative was not approved.
Supporting data, where
necessary to assist in the approval of materials or assemblies
not specifically provided for in this code, shall consist
of valid research reports from approved sources.