I spent a lot of time thinking about what viewpoint I would like to illustrate. I got a photosphere from street view from Kalmar to get accurate lightning.
Next have spent about 3 hours or so on modeling first, which yielded a rough 3D draft. Then I spent about 1 hour to clean up all the windows to make them the right size. You spend about 20% on the rough modeling and 80% on getting the shot right. Since I am behind on the modeling, I got a material test render done which is what you are seeing above.