While I usually find some architectural renders interesting to look at, I've never actually had the desire to make one myself - - but then I got this idea about making something with major flaws; doors in the wrong place, stairs with less than optimal alignment and so on... and I came up with this after about four days of work.
The intention is to make something reasonably believable, yet hopefully giving the impression that "there's something seriously wrong with this picture".
Concept aside, it was a lighting excercise, mostly in terms of getting a nice result in the relatively large areas that only get indirect light. I used four cyan/blue area lights around the scene to get a diffuse daylight, a yellow/orange parallel spot with hard shadows for the sun, and six or seven omnis in various places for bounced light.
Aside from some ambient occlusion, it's traditionally lit, and finally rather extensively tweaked in photoshop using object buffers and a depth pass.
C & C welcome - particularly lighting related.