CRE Asset Types hard or impossible to finance?

[AP Horvath]

It used to be that self-storage was difficult to finance -- now it looks like many local commercial banks are happy to do so. The upside is that it is easier to get a self-storage deal done -- the downside is, it is easier for the average Joe to get a self-storage deal done too. 

And when money is cheap and a lot of average Joes are jumping in the same asset class -- cap rates plummet. That's obv good if own assets in that class -- but makes the game tougher if you're trying to get in and actively acquiring properties. 

So the question is:

What are the current CRE asset types that are hard to finance? (But will become easier over time.)