(1) For the purposes of this Part, existing buildings shall be classified as to their construction and occupancy as provided for in Sentence 11.2.1.1. (1).
(1) Where proposed construction will result in the change of major occupancy of all or part of an existing building to another major occupancy, the building shall be classified as to its,
(a) construction on the basis of its construction index as provided for in this Part, including Table 11.2.1.1.A., and
(b) occupancy on the basis of its hazard index as provided for in this Part, including Tables 11.2.1.1.B. to 11.2.1.1.N. (2) Small or medium sized existing buildings as determined in Tables 11.2.1.1.B. to 11.2.1.1.N. facing multiple streets may be assigned a hazard index credit of 1, which may be subtracted from the hazard index of the proposed major occupancy to reduce the additional upgrading required by Table 11.4.3.4.A. provided,
(a) the building does not contain a Group B, Division 1, a Group C, or a Group F, Division 1 occupancy, and
(b) firefighting access complying with Articles 3.2.5.1. to 3.2.5.5. or Subsection 9.10.20. is provided. (3) The requirements of Articles 3.2.2.20. to 3.2.2.83. do not apply to this Part.