Some of them are straightforward lighting design studies, where the visualization was just used as a plausibility check on the numeric simulations, while others are modelled in more detail and rendered more thorougly. This is usually the case with projects where the client explicitly demanded photorealistic images.
Office entry hall, Coburg, Germany
ICE Train Station
Airport Frankfurt/Main, Germany
"Am Borsigturm", Berlin, Germany
Airport Leipzig, Germany