Notwithstanding any other provision of law, if a determination that an unsafe or substandard condition exists in any building, or upon the lot upon which it is situated, has been made in an administrative proceeding conducted under this part, including any code incorporated by Section 17922, the enforcement agency may abate the nuisance as provided in this part or exercise any other authority conferred upon it by this part, subject only to the exclusive remedy of the owner to challenge the administrative determination pursuant to Section 1094. 5 of the Code of Civil Procedure. The court may exercise its independent judgment on the evidence to determine whether the findings are supported by the weight of the evidence. This section shall apply only to administrative proceedings commenced on or after January 1, 1990.