The question often comes up from people what to go with when it comes to a permanent set up. I had an observatory back east. I enjoyed it and it was an excellent shelter for my long focus newtonian but if I had to do it over I probably would have chosen a roll off roof structure for there. Here is my list of pluses and minuses for each design:
Pluses: Excellent wind protection and shields ambient light
Walls are usually low so you will be able to view down to the horizon
Much more room for your equipment since the dome height allows for more flexibility with scope position and size
Minuses: Usually more expensive
Unless you have a clamshell type design you aren’t going to see much of the sky if you are interested in being out there
If you are an imager, you are going to go crazy if you don’t have dome automation since you will HAVE to go out there periodically to manually move the aperture anywhere from every hour to every few hours depending on what you are imaging. Dome automation is very costly! It is also very challenging to get it to work properly.
2) Roll-off roof.
Pluses: Generally easier to build and operate. Also often less expensive
No issues with imaging unattended once the roof is open. No need for expensive software and other components. Opening a roof remotely if desired is probably a lot cheaper and easier than opening a dome
Minuses: You won’t get the wind protection like you can with a dome
You might have to sacrifice some horizon sky since this design will have more limitations on how the scope can be parked in order to get the roof to close. If the walls are too low you won’t be able to close the roof. If you use a smaller structure, the walls will be closer in and this becomes more of an issue.
Next up, TSH roll-off observatory progress report!