This study evaluates the viability of combining solar photovoltaic (PV) and rainwater collection systems in a hospital car park in Mosul, Nineveh Governorate, Iraq, to increase cost savings, sustainability, and resource efficiency. In the proposed system, two steel structure designs are used: Type 1, which has a three-section roof with a 0-degree slope and two 45-degree slopes oriented eastward and westward, respectively, and Type 2, which has a 25-degree tilt angle oriented eastward and west to maximize energy production and collected rainwater for irrigation and cleaning. To this aim, RETScreen and SAP2000 for the techno-economic feasibility and structure analysis, respectively, were utilized in this study. The results indicate that the Z-section design was the optimum choice for both structures based on SAP2000 data. This design offers superior stability, strength, and efficiency under various load conditions, such as wind and seismic forces. Additionally, the RETScreen results demonstrate that Type 1 performs better than Type 2 in terms of energy output and economic feasibility. This hybrid system offers substantial financial benefits and a sustainable means of reducing dependency on conventional water and energy sources, thereby making it an attractive option for urban infrastructure projects. Furthermore, the study encourages the UN Sustainable Development Goals (SDGs), particularly Goal 7 (Affordable and Clean Energy) and Goal 11 (Sustainable Cities and Communities), by promoting the combination of renewable energy and resource efficiency.