I don't have any dedicated space for bikes but have am fortunate to have plenty of shop space. Since I stopped messing with cars and bikes I don't need all the space and in the last couple of weeks have been trying to get some space partitioned off for sort of a small man cave/work shop that can be heated and cooled more reasonably. I built it about 8 years ago, here is a picture from a couple years or so back.

I built the partition across the back 2 bays with an 8" ceiling so that I could store stuff on top of it. It had gotten pretty piled up since I stopped working on cars (sold the lift, all of my powder coating equipment in the last year) but here it is as I finished over the weekend.

I'm about half done with what I've got in mine for this evolution. I will have a dedicated bike area in the back room. I've got an old (1956 Lodge & Shipley) lathe I'm restoring and I'd like to refinish my mill (1971 Enco J-head clone) alone with a couple other personal but non bike related projects.