I have had 2 antennas mounted to the side of my house onto the chimney, a Sirio tornado and the vector 4000. I did experience some issues with the Tornado as it was only about 24ft to the base which only put it above my house a little over 10ft with the chimney it was less than that. Anyhow it wasn't until I got the base of the tornado to near 30ft off the ground that it made things better. No complaints from the neighbors after that. And yes they were having issues before the move. Now the Vector 4000 didn't give me any issues at all. But I did mount it at about 26-27ft off the ground. And I did use ferrite chokes on both antennas at the feedpoint as well. Needless to say, it depends on the antenna IMO, and yes placement if very important. What might not affect anything in your house like I was with me, in which case none of my electronics had been affected, my neighbors got a bit sore at me after a while of hearing me call CQ through their computer speakers LOL!! Also I did add a Low Pass Filter when I used the Sirio Tornado, but found no need for it with the vector 4000. Radio being used was an Icom 746.
Try both areas if possible. You might get lucky and not bother anyone, but also check with the neighbors as welol especially if you are friends with any of them. Just the house or houses closest to the antenna. These are just my own experiences and yours may totally differ.
If you could get the antenna up to about 20ft or more from the top of the roof it might work much better, the antenna that is, and not cause any issues with anyone. But I'll have to agree with the others about having it only 15ft off the ground. It will most likely cause some issues at that height. But ya never know until you try. Also the use of a radio that transmits a clean signal will be of benefit for sure. Clean in equals clean out and vise versa. Hope you get it setup and working properly. And be safe in the process. Take your time and have as much help as possible. Good day.