Exterior Lighting and Sky

[tehquickness]

I was wondering about the process some of you use when doing exterior building renders with a sky in the background? I know this is probably really dumb, but I always feel like I should be able to get a perfect image right out of the render engine.

 

I am assuming most of you must render the building then do the background, people, plants, etc in other passes or just added in photoshop? I just wanted some feedback.

 

Thanks