The study employs the fuzzy Delphi method to set evaluation indicators and factors, followed by the Analytic Hierarchy Process (AHP) to establish weighting relationships, incorporating failure modes and a grading system to construct a comprehensive evaluation model. This includes four main indicators: Safety and Sturdy (SS), Reasonable and Completeness (RC), Health and Sanitary (HS), Comfortable and Sustainable (CS), along with sixteen factors. The overall score (UI) is calculated on a common percentage scale, with scores below 60 deemed unqualified, between 60 and 79 as qualified, and above 80 as excellent. Threshold indicators and failure factors are set to ensure the model’s viability. Demonstrated through actual case evaluations, the model’s strengths and weaknesses are reviewed, extending the evaluation to traditional bathrooms for a deeper examination of the discriminatory and rational aspects of the results. Monte Carlo simulations of large data sets reveal approximately 33.7% of cases fall into the unqualified range, and about 9.4% into the excellent range, indicating the model’s discriminative ability. Both threshold indicators and failure factors play a critical role in case evaluations.