During our career studies, we perfected our modeling technics and understandings of what architectural models should represent. In an early period of our services, we collaborated with architectural offices, making professional models for competitions and license obtaining processes.
The materials we used were mostly PVC sheets for base neutral white volumetry, combined later with other materials and colors, depending on what we wanted to express with a model. We always treated first the surfaces with sandpaper to eliminate the glow, then cut manually the pieces, glued them together with chloroform dilution, and finally treated again the joints with sandpaper, to eliminate the glows that chloroform dilution would create. As a result, we were obtaining perfect volumes that could be left like raw material, without painting.
The major advantage of this technics was a cost/result ratio for small and medium-sized models and working flexibility (easy to fix any error or make a step back and correct it). PVC sheets are cheaper, more flexible and much easier to treat than methacrylate sheets, which, adding the expense, have to be cut by laser. For bigger size models and complicated pieces, of course, laser cut pays off.