(a) No provision of this Building Code shall be interpreted to prohibit or prevent the use of assemblies prefabricated off the site or at the site of construction, provided such assemblies conform to the provisions of OBBC or this Building Code or to the terms of an approval given by the Board of Building Standards and Building Appeals.
(b) Where the component parts of prefabricated assemblies are not readily accessible to inspection at the site, the Commissioner may accept certification that the assembly as installed at the site is identical with specimens upon which approval was based. If mechanical and electrical equipment are so installed as not to be readily accessible to inspection at the site, certification may be required that such equipment complies with applicable laws and ordinances, or the terms and conditions upon which approval was based.