Integrating urban green spaces is essential for sustainable city planning, providing numerous ecosystem services that enhance urban resilience and quality of life. This study examines the benefits of using low-cost GIS-based tools for evaluating ecosystem services of public and private green areas within urban environments. Specifically, we developed four indicators using QGIS software, leveraging its open-source capabilities and easily accessible data from local authorities and industry professionals. Centimetric high-resolution multispectral orthoimages (4 bands: RGB and Near Infrared, NIR) were utilized to calculate the Normalized Difference Vegetation Index (NDVI). The study area, comprising 50 hectares on the outskirts of Lucca, Italy, was divided into 1-hectare grid cells for detailed analysis. Using NDVI data, we defined the following indicators: 1) Permeable Area (PA), which addresses the capacity of green spaces to manage adverse climatic events like floods, thus correlating directly with urban resilience and recovery functions; 2) Pollutant Removal (PR), which assesses the green areas’ efficiency in mitigating urban emissions predominantly from traffic, industrial activities, and residential heating/cooling systems; 3) Heat Island Mitigation (HIM), which evaluates the role of green cover in reducing urban heat islands, particularly in areas with limited arboreal coverage; and 4) Public/Private Green Area Ratio (P-GAR) which explores the nature and distribution of ecosystem services provided by urban green spaces. These indicators, derived from the combined use of NDVI and Land Use/Land Cover data, demonstrate that low-cost GIS tools can facilitate reliable and robust environmental assessments. The results underscore the potential for these tools to aid managers and professionals in conducting comprehensive studies within urbanized areas, thereby informing sustainable urban planning and environmental management strategies.