Blender 2.65a, render in BI...yes BI
So....
Floor was modeled, texture is Blender's cloud texture, pulled along the y-axis, bump added, no color. Two area lights outside the windows, one big fill area light to the left. Sun added, as well as environment lighting set to white. No other walls other than what you see, and for those who don't know, this was done with Blender's internal render engine(not Cycles) without the use of global illumination. Direct lighting only. Everything else is really self-explanatory, cubes, circles, etc. Nothing special. Artwork from the internet(I love art nouveau stuff). No post-pro whatsoever as usual :D
EDIT: WOW, thank you all for the love and the feature! I am honestly blown away! *faints*