This is a fully finished, live-in capable attic with harwood floors, tongue and groove pine board walls and ceiling. The entire finished attic is both heated and air conditioned. As noted, I have had a finished, but backdropless DC operated, HO layout in those eves since 1980 and only in mid-2011 have I been re-doing the setup as an HOn3 layout. Admittedly, even with AC, the peak area of the roof can be rather warm in summer. I live in Virginia.
I just have never seen or heard of anyone working up in the ceiling eves in an attic, finished or not. I was forced to do this when I built my first layout in this home on the floor in 1976 and found out I needed the upstairs floor space for other purposes.
I was quite proud that I got about 5X more layout open run distance over my older layout when I went to the elevated train layout to reclaim 100% of my floor space. The wife relinquished the entire finished attic as my man cave when we first moved in and rarely comes upstairs for any reason.
Right now, I am a bit concerned about how I do the backdrop as I must have it on this new road. Photogrpahic work is a must, as is a decent backdrop to give some realism.
Thanks to Mister Beasley for his advice, images and comments.