Export it at the largest size image you can [see options ~3000px], and turn anti-aliasing off. Resize the image in your document. To get a 'scaled version' perhaps add a 'scale-bar' to the image to assist in that... Or try 'Layout' ?

Switching off profiles and edges etc does it for me

There are several good tutorials on roof creation... try http://www.youtube.com/watch?v=A6WxE6oO3JU or http://forums.sketchucation.com/viewtopic.php?p=108902#p108902 Also see this http://forums.sketchucation.com/viewtopic.php?f=18&t=752&p=4312&hilit=+roof+tutorial#p4312

It is a feature of the "Sketchy edges" style that you are using. Smaller details fade away the farther they are from the camera. Your mullions became visible when I moved the "level of detail" slider in the Style Edit window to the far right. The fading cannot be turned off altogether, so if that is not enough, the only option is to switch to a non-sketchy style. Anssi