Revenue and Taxation Code – RTC § 74.6
(a) For purposes of paragraph (4) of subdivision (c) of Section 2 of Article XIII A of the California Constitution , “newly constructed” and “new construction” does not include the construction, installation, removal, or modification of any portion or structural component of an existing building or structure to the extent that it is done for the purpose of making the building or structure more accessible to, or more usable by, a disabled person.
(b) For the purposes of this section, “disabled person” means a person who suffers from a physical impairment that substantially limits one or more of that person’s major life activities.
(c) The exclusion provided for in subdivision (a) shall apply to all buildings or structures except for those buildings or structures that qualify for the exclusion provided for in subdivision (a) of Section 74.3 .
(d) The exclusion provided for in this section does not apply to the construction of an entirely new building or structure, or to the construction of an entirely new addition to an existing building or structure.
(e) For purposes of the exclusion provided for in subdivision (a), the property owner, primary contractor, civil engineer, or architect shall submit to the assessor a statement that shall identify those specific portions of the project that constitute construction, installation, removal, or modification improvements to the building or structure to make the building or structure more accessible to, or usable by, a disabled person.
(f) For the purposes of the exclusion provided for in subdivision (a), the construction, improvement, modification, or alteration of an existing building or structure may include, but is not limited to, access ramps, widening of doorways and hallways, barrier removal, access modifications to restroom facilities, elevators, and any other accessibility modification of a building or structure that would cause it to meet or exceed the accessibility standards of the 1990 Americans with Disabilities Act ( Public Law 101-336 ) 1 and the most recent edition to the California Building Standards Code that is in effect on the date of the application for a building permit.
(g) In order to receive the exclusion provided for in this section, the property owner shall notify the assessor prior to, or within 30 days of, completion of any project covered by this section that he or she intends to claim the exclusion for making improvements of the type specified in subdivision (a). The State Board of Equalization shall prescribe the manner and form for claiming the exclusion. All documents necessary to support the exclusion shall be filed by the property owner with the assessor not later than six months after the completion of the project.
(h) This section applies to any construction, installation, removal, or modification completed on or after June 7, 1994.