(A) All Class 1 buildings (as defined in 675 IAC 12-6) or portions of Class 1 buildings hereafter constructed shall be provided with a water supply cable of providing the required fire flow for fire- fighting purposes for a minimum period of two hours. The water supply shall be from a source as set forth in § 903.2 of the IFC (675 IAC 22). In setting the requirements for fire flow, the Code Enforcement Chief may use the IFC (675 IAC 222) Appendix III-A as a guide.