Presenting your VR projects to clients?

What are currently the limitations that prevent UE4 to be used in VR (Oculus or Gear VR) though HTML?
Has anyone succeeded using UE4 with Gear VR or Oculus for architectural walkthroughs (not in HTML)?

I am fairly new to UE4 and still trying to understand where is the technology at the current stage, what is possible and what not.
Thank you in advance!