**4. Conclusions**

The potable water savings potential ranged from 15.80% to 24.43% when considering both roof area possibilities. The results were higher than those obtained in the literature for multi-family buildings and lower than those found for single-family buildings. Additionally, it was found that even the smaller roof area proved to be an exciting approach for the users, starting a sustainable water practice in the flat.

The flat presented higher consumption than the region's average water consumption, and one can postulate that the continuous stay of users due to pandemic isolation might have influenced the results. The non-potable water demand percentage for the flat was similar to previous literature. Further studies can better understand the effects of different user patterns, helping to improve rainwater harvesting dynamics.

**Author Contributions:** Conceptualization, I.C.M.V. and E.G.; methodology, I.C.M.V.; software, I.C.M.V.; writing—original draft preparation, I.C.M.V.; writing—review and editing, I.C.M.V. and E.G.; supervision, E.G. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Informed consent was obtained from all subjects in the study.

**Data Availability Statement:** The data presented in this study are available on request from the corresponding author.

**Acknowledgments:** We would like to thank UFSC for their support and Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) for the first author's scholarship during this research.

**Conflicts of Interest:** The authors declare no conflict of interest.
