All public accommodations constructed in this state shall conform to the provisions of Chapter 7 (commencing with Section 4450) of Division 5 of Title 1 of the Government Code. However, the following types of privately funded multistory buildings do not require accessibility by ramp or elevator above and below the first floor:
(a) Multistoried office buildings, other than the professional office of a health care provider, and passenger vehicle service stations less than three stories high, or less than 3,000 square feet per story.
(b) Any other privately funded multistoried building that is not a shopping center, shopping mall, or the professional office of a health care provider, and that is less than three stories high or less than 3,000 square feet per story if a reasonable portion of all facilities and accommodations normally sought and used by the public in such a building are accessible to and usable by persons with disabilities.