Thanks for the feedback guys
I do like the idea of a roll off roof, with the extra space it provides and visibility of the sky above but it is wind that I worry about
..We have had high wind levels up here several days/nights already (up to Beaufort scale 7), certainly a couple of them I wouldn't have opened a dome, let alone a roll off roof observatory
It's been my experience, that if the wind is anything up to
fresh (Beaufort scale 5) and I am not imaging directly into the wind, the current 2.3m Sirius dome works beautifully as protection, even with the dome slit fully open and if I can shut the lower shutter ie once I am imaging over about 45deg or so above the horizon, I can probably handle up to Beaufort scale 6 without serious adverse affects on tracking. Pretty sure this would all be impossible in any roll of roof scenario..?
Interesting approach there Steve, sounds reasonable.
Yes, I am keen to build the observatory up off the ground, so given the winds, it will need to be built tough and strong...err?..like it's owner...
once was 
Mike