I’m looking for a GIS specialist who can help me estimate how much roof space in a small city or town could realistically host semi-intensive green roofs. I do not have existing building footprints, so part of the assignment is to source or create that data—whether from OpenStreetMap, open municipal datasets, high-resolution imagery, or another reliable source you propose. The job breaks down into two clear outcomes: • A geospatial dataset and map layer showing every building roof, flagged as suitable or not suitable for semi-intensive green roofs, with surface area figures attached. • A concise, step-by-step technical document that explains exactly how the data were sourced, processed, and analysed, so the workflow can be replicated or audited later. In the analysis, I need the total roof area deemed suitable expressed both in absolute square metres and as a percentage of the city’s total land area. Typical factors such as roof slope, material, and minimum contiguous area should guide the suitability rules, but feel free to recommend other criteria you feel are critical for semi-intensive systems. Accepted formats: shapefile or GeoPackage for the spatial data, PDF (or Markdown) for the methodology report, and a high-resolution map image for quick reference. I routinely work with QGIS, so compatibility there would be a plus, though ArcGIS Pro, PostGIS, or Python (geopandas, rasterio) are also welcome if documented clearly. If this sounds like a project you can deliver, let me know how you would source the building data and what tools you would rely on to complete the task.