Thanks again for all your compliments and ideas. Some of them are really great and we are looking forward to implementing them in the next projects. For example about people doing “stuff” 
(@ )…in our past we did a lot of offline rendering arch-vis and we also used peolpe for giving life to the pictures…i think we have to do it for realtime too
@ Seirei: usually we uncheck the “lower hemisphere is black” checkbox, also in this project. And to say something more for the skylight: the intensity is 2 for this project. In one of our last projects the intensity was 4. Usually we start with the six lights with really low intensity (something like 0.03) and do a pre-building. After these six lights we add the skylight (try with static and stationary, sometimes it is much better with stationary) and also do some pre-buildings. If the results are good, we add the reflectors with the spotlights in front of the windows. And also do some pre-buildings At the end we add the sun, sometimes as static, sometimes as movable (depends on the type of project).
For this project there were two people working on it. But this only implicit the buildup and the setup for the scene, like build the lab, arange the furniture, lightsetup, build some furniture (like two chairs, the reception, etc) and so on. These two people worked for a week on it. The most furniture themselves were produced in other projects.
We hope that we could address your questions and if you have more feedback or questions in general regarding this project, feel free to ask us anytime.