Graveyard Clean-rooms

Central user facilities are appearing everywhere - and they are a great way to make sure that everyone in a given community has access to the same equipment, not just the Nobel Laureates who bring the multi-million dollar grants. But, at the same time, there is limited space in these facilities.

This may not be a big of a problem in the life sciences (but here I'm rather out of my league, as I'm not in the life sciences, so please feel free to correct me), but in engineering where most of the equipment is put in clean-rooms, space is fought over. This brings me to my next point. Whose equipment is most important and who gets to decide?

Is it the assistant professor's new X, which is critical to their success, but no one else really cares about it/uses it or is it the tenured professor's Y, which is occasionally used, but 8 yrs ago produced a Nature and/or Science paper. Or, is it the department chair's Z, which is currently broken and just taking up space, but it cost a trillion dollars (not literally) when it was initially purchased, so no one wants to be the one to trow it away.

In the perfect world, there would be space for everything, and a choice wouldn't have to be made. But progress happens, and new equipment needs to be purchased in order to stay at the cutting edge. But to buy new equipment, it is necessary to show the granting agency gods that you have a place to put it - and right now, that place doesn't exist because of the graveyard that is the clean-room.