I think the ability of walking through a building in VR is going to be useful not only for marketing but also during the design process (maybe even just with clay models). I listened to a couple VR podcast about that and that’s what they were telling. The interactivity is a gimmick imo. It will get old FAST!
I would focus my energy on composition/mood/story instead of programming complex blueprints just to be able to open a door. No one needs to experience how a door opens, close a light, open a tv, etc. but everyone will want to experience the scale of a building, and how you feel in a given space, etc. That’s the true meaning of virtual reality imo.