thinking o' building

We may be building a 2-story building- small rehearsal room (soundproofed for musicians)on the ground floor with an office space on the top. While we're building, I'd love to put an observatory on the roof. All this is on the extremes of hypothetical, but what is the ballpark figure (yeah, right) to put a dome or a roll-top roof up? Why would I choose one over the other?
If I do it, I'm gonna get a bigger scope than my 8" Dob...
mary

Mary,

All very good questions about a second story observartory. I am just about finished with mine now, and I went with the roll off roof. Only because I like the feeling of being outside, if I want to use binoculars I can on another section of the sky, My wife can use another scope or binoculars when I am at the main scope. And if you like to slew all over the sky then you will have to be moving the dome all the time too.
From what I found is that if you are going to be doing alot of Photography the dome is great, if you are in a very very cold climate the dome would help on those nights too.
Everyones needs are different.

As far as cost
you can be all over the board on this one
Depends on what you want to mount in there, and if your roof is motorized, are you going to temp control it at all so when the roof is closed you can work in there?

MarkK