Supplementary_material.docx

Urban water management faces growing pressure from population growth, pollution, and climate variability, demanding innovative strategies to ensure long-term sustain-ability. This study applies Life Cycle Sustainability Assessment (LCSA) across four case studies in Brazil and Germany, evaluating integrated systems that combine construct-ed wetlands for greywater treatment with rainwater harvesting for non-potable use. The scenarios include a single-family household, a high-rise residential building, a ru-ral residence, and worker housing. A multi-criteria analysis was conducted to derive consolidated sustainability indicators, and sensitivity analysis explored the influence of dimension weighting. Results show that water reuse scenarios consistently outper-form conventional counterparts across environmental, economic, and social dimen-sions. Life Cycle Assessment (LCA) reveals notable reductions in global warming po-tential, terrestrial acidification, and eutrophication. Life Cycle Costing (LCC) confirms financial feasibility when externalities are considered, especially in large-scale systems. Social Life Cycle Assessment (S-LCA) highlights perceived benefits in health, safety, and sustainability engagement. Integrated water reuse systems achieved overall sus-tainability scores up to 4.8 times higher than their baseline equivalents. These findings underscore the effectiveness of decentralized water reuse as a complementary and ro-bust alternative to conventional supply and treatment models, supporting climate re-silience and sustainable development goals.