Hi Alex,
for some reason the 'diy obs' section has only 2 pages now ? Anyway, there was a thread on my recent (1.5yr ago build) which is a 'Roll-Away' scope keeper - small shed which has shelving inside & what-not,,, Plus there I put up a seperate, small garden-shed for the PC & gear room, , which is awesome with a kettle, small heater in the dead of winter etc !
As you have mentioned 'you liking the open space' I really enjoy it too, and this arrangement I have lets one enjoy the open sky to its full !
Not only that, but 'Rigging your scope, changing things etc etc is a god-send when the walls are 'not there to bump into, hit head on, awkward bending, getting gear in through a tiny door - this list goes on & on !!
And tho Not only these benefits, but also when have visitors, 'if you do' as I do from time to time - it is very spacious for peeps to squizz at & through the scope and gives a more personal connection to the heavens, for them & self !!
Have found some pics in my archives !
Obviously what one uses to build either as I have, is entirely upto them, materials, size etc etc
Just thought to mention this your way, as it covers all areas I think, A Three-Way Astro Area,
1) Have something to 'roll-away' Lol
2) Have a seperate 'Warm-Room'
& 3) Have open space