Existing law, the California Building Standards Law, establishes the California Building Standards Commission within the Department of General Services and sets forth its powers and duties, including approval and adoption of building standards and codification of those standards into the California Building Standards Code. Existing law requires the commission to adopt specific building standards, including standards for graywater, and to publish, or cause to be published, editions of the California Building Standards Code in its entirety once every 3 years. Existing law establishes the Building Standards Administration Special Revolving Fund, and makes the moneys in the fund available, upon appropriation, to state entities to carry out various related provisions, as specified. This bill would require the department to research, develop, and propose building standards to reduce potable water use in new residential buildings and imposes those duties on the commission with respect to new nonresidential buildings, as specified. The bill would require the commission to perform a review of water efficiency and water reuse standards in the California Buildings Standards Code every 3 years, commencing with the next triennial edition, and update as needed. Existing law establishes, within the California Environmental Protection Agency, the State Water Resources Control Board for the purposes of orderly and efficient administration of the state's water resources. Existing law requires the board, in consultation with the commission and the Department of Housing and Community Development, to adopt regulations for risk-based water quality standards for the onsite treatment and reuse of nonpotable water in multifamily residential, commercial, and mixed-use buildings, as specified. Existing law requires the department, in consultation with the board, to develop and propose for adoption any necessary corresponding building standards to support those risk-based water quality standards by a specified date. This bill, instead, would require the department, in consultation with the board, to develop and propose the corresponding building standards within 12 months of the board adopting those regulations. This bill would also make related findings and declarations.