Open plans as a way to avoid "siloing" is the wrong solution to a much bigger problem.
The flipside is that, if you spend a half hour figuring something out instead of interrupting me, you don't interrupt my flow, which could translate into a much greater reduction in productivity than if you'd just dealt with it yourself.
Put another way: open offices make it too easy to interrupt someone else.
In our space we find a balance with electronic communication. Two person offices reduce distraction. IRC and email serve as a middle ground to interruption (as folks on the receiving end can control when the interruption occurs). Interruptions in meatspace only occur when they're actually necessary.
Edit:
And I forgot the other big benefit: two person offices mean you can co-locate people who work in the same product area, and when broader discussions need to happen, the offices can double as meeting spaces without everyone else being interrupted by the conversation.
So offices actually assist in facilitating communication as the threat of distracting others is substantially reduced.
If you don't interrupt me, you lose 30 minutes of your time solving your problem (and, by the way, learn to learn along the way).
If you do interrupt me, you save yourself, say, 25 minutes, while I probably lose 60 minutes of effective flow time ("gee, I'm distracted now, might as well go to the bathroom and get another coffee while I'm at it... oh hey, look some emails, let's take a look at those...").
And that's ignoring the distraction you create for all the folks around me as you come and ask your question.
So in terms of overall team productivity (which is a function of the individual productivity levels of the team members), I will happily take the bet that open offices are far worse than closed ones in the the scenario you've proposed.
That seems very inefficient for most questions. Why not ask online instead?
I wonder what happened to the health aspect of this. How about walking over? Where is the problem? Pro Tip: take the stairs. You can even sit down then if there is enough space for a second chair.
The opposing idea is that in the long-term picture, choosing to spend more time now in order to figure it out yourself leads to developing the very skills that will let you avoid needing help in the future. Much like coding every day makes you a better coder, debugging things yourself makes you a better debugger.