Don't let anyone tell you sketchup is not a 'serious' modeling program and that it produces untidy geometry, like any program its how you use it that counts. The genuis of sketchup lies in it's tidy interface, brilliant snapping, and ease of use. Sketchup has it's limits of course, but for architectural visualisation I think it is the perfect tool for modeling. Every single project in my portfolio started life in sketchup. The start of any project for me is understanding the building and modeling it - as quickly and as efficiently as possible. This timelapse screen recording shows the whole process, speeded up 10x. The whole thing took about a day (3 hrs 46mins, excluding all the coffee breaks). I like to get the overall form of the building done first, but identifying and making components for any repeating elements (windows, doors, whole apartments) as I go. You can then go back and add detail later on.