Observatory Orientation

How would one choose to orient a roll-off observatory?

Assume on level ground the construction of a 10 X 12 structure at lat 40 degrees. FOV is 360 degrees with a minimum achievable scope elevation of 15 degrees above the horizon (trees).

My concern is how much the actual structure would impose on the sky at the telescope mounted on approximately 42" pier.

My tendency is to orient the structure along the long axis to True North assuming that any structure obstruction would block some portion of the North sky from 15 degrees to at least 30 degrees in elevation at about max horizontal angle of 10 degrees either side of TN. IMO, this part of the sky being least important for my purposes.

Hi Louis,
I had similar problems with where to locate a dome observatory on my property, mostly due to neighbor's floodlights and a stand of mature cacti. It's due south of the tallest cactus, which is about twenty three feet high and forty feet away.

I can see everyhing within 10* of Polaris. I'm pretty much unobstructed to the south. There's a mountain range to the east but just under 15*. The city of Phoenix is west of me so anything below 35* from that horizon is in the light dome.

Anything within 15* of horizon is not going to show up well anyway just because of atmosphere. I mounted the dome six feet up to keep my eyes well away from the anoying lights, and the scope is tucked in with just enough vertical space to give me that 15* and let the lip of the dome block direct light from the floodlights down the road.

Hope that helps.
Thanks,
Steve
8)