Cal. Civil Code § 1101.5

(a) On or before January 1, 2019, all noncompliant plumbing fixtures in any multifamily residential real property and in any commercial real property shall be replaced with water-conserving plumbing fixtures. (b) An owner or the owner’s agent may enter the owner’s property for the purpose of installing, repairing, testing, and maintaining water-conserving plumbing fixtures required by this section, consistent with notice requirements of Section 1954. (c) On and after January 1, 2019, the water-conserving plumbing fixtures required by this section shall be operating at the manufacturer’s rated water consumption at the time that the tenant takes possession. A tenant shall be responsible for notifying the owner or owner’s agent if the tenant becomes aware that a water-conserving plumbing fixture within his or her unit is not operating at the manufacturer’s rated water consumption. The owner or owner’s agent shall correct an inoperability in a water-conserving plumbing fixture upon notice by the tenant or if detected by the owner or the owner’s agent. (d) (1) On and after January 1, 2014, all noncompliant plumbing fixtures in any multifamily residential real property and any commercial real property shall be replaced with water-conserving plumbing fixtures in the following circumstances: (A) For building additions in which the sum of concurrent building permits by the same permit applicant would increase the floor area of the space in a building by more than 10 percent, the building permit applicant shall replace all noncompliant plumbing fixtures in the building. (B) For building alterations or improvements in which the total construction cost estimated in the building permit is greater than one hundred fifty thousand dollars ($150,000), the building permit applicant shall replace all noncompliant plumbing fixtures that service the specific area of the improvement. (C) Notwithstanding subparagraph (A) or (B), for any alterations or improvements to a room in a building that require a building permit and that room contains any noncompliant plumbing fixtures, the building permit applicant shall replace all noncompliant plumbing fixtures in that room. (2) Replacement of all noncompliant plumbing fixtures with water-conserving plumbing fixtures, as described in paragraph (1), shall be a condition for issuance of a certificate of final completion and occupancy or final permit approval by the local building department. (e) On and after January 1, 2019, a seller or transferor of multifamily residential real property or of commercial real property shall disclose to the prospective purchaser or transferee, in writing, the requirements of subdivision (a) and whether the property includes any noncompliant plumbing fixtures. This disclosure may be included in other transactional documents.