Okay, so I'm not an architectural modeler, but I can give you some idea as how to approach the roof for the high polygon modeling. What you're going to do is model a single single / tile / whatever, and place it at one of the roof corners. Next, you'll go to the duplicate tab and use the array function. What you might want…
@Zyhael, That pipe is probably meant to be a gutter drain. It does have a round support bracket mounted against the wall. Anyways, I'm glad that the array trick worked. It's coming along splendidly. :)