The last company I worked for had nothing BUT a P.O. box. We moved a lot for various reasons, but the fact is every document for our organization was delivered to a P.O. box. Yes, it was sometimes dreary to have to run to the post office every morning (4 blocks away), but nothing like changing EVERY mailing address every time we moved. I would say that is fairly normal.
The truth is BIHC may not even have office space, why would you need it?