Your comment about your building room shared with radio... is my situation as well. I still have all my radio and test gear in my building room. I'm an inactive Ham however, and should clear out the radio stuff but I'm loath to part with what was once important I guess but I have given thought to selling the stuff and making more room. I guess what holds me back is that I've been forced a couple of times to change gears hobby wise so with an awareness that nothing in life can be certain, I might one day want to reactivate as a Ham so why sell out for peanuts.
And... I've got one bench with test gear; a scope, poor mans spectrum analyzer, sweep generator, and various other test gear.
I hear you about the fumes. My radio/airplane room is in the house but behind the garage with three doors, to the garage, back yard and living area. I can close that door and otherwise ventilate fumes between the garage and back yard. It works most of the time but have been fussed at a time or two. I do have a very nice setup for modeling with a back yard shop only a few steps from the back door of the building room and storage for planes on garage walls and ceilings.
It is very nice to have a heated/cooled building room and such is a worthy trade for more size.
btw, last night was spent buttoning up a few odds n ends on the SW. The cowl was left off for now and probably through the maiden and all is ready for firing the engine and getting idle and failsafe set. Might get that done this evening if not too tired. I started a construction project yesterday so will have less time and energy for modeling for a while.