Hi Georg,
I can imagine seeing that roof and being just as drawn to it as you were.
Unfortunately, for me, it just doesn't seem to work. There seems to be plenty of contrast there, but the overall feel is of low contrast images.
The 2nd image is by far the best and quite abstract in it own right, but perhaps suffers a little from being with the other two. The first and last are too busy with a lack of center of attention.
Im very curious. Are you happen with them (1 & 3)? Are they experimental?
Disclaimer: I am not a critic, and always seem to be with the minority opinion when it comes to photography.
Joe