As we get used to the idea of consumer virtual reality, we shouldn't forget that architecture firms, construction companies, and research institutions are way more hardcore than you and your paltry living space will ever be. One of the companies that fills this niche is WorldViz, which has been helping these places make walkable VR worlds since long before ordinary people started bashing their hands into walls playing virtual tennis. Today, those two worlds meet as WorldViz adds tracking support for the Unity and Unreal game engines that power many (if not most) virtual reality experiences.
What does this mean for you? If you have a 50 x 50-meter space and nine friends to join you, it's now easier to set up a VR system that will incorporate both those things, using a series of very precise cameras and sensors that can be attached to any headset. Among other things, this could make it relatively simple to do what WorldViz calls "warehouse-scale tracking" with a wireless headset like the Samsung Gear VR or Google's yet-unreleased Daydream viewer, instead of carting around a portable desktop computer or being tethered to a wall. Worldviz also uses its own controller, so you don't have to worry about trying to adapt something like the Gear VR's trackpad to motion-based input.
If you happen to not have the $15,000 or more that this will cost to set up, you could still encounter one of these in a university department like Stanford's Virtual Human Interaction Lab, where researchers study how people think about themselves or communicate with others differently in virtual reality. If you're building a house, you could potentially use it to walk through the space before it exists in the real world. Or you could just stare at the masterful encapsulation of modern human isolation that WorldViz has chosen as its press shot. While you can't see it very well in the picture, the image on that wall is a fairly intimidating "walk the plank" demo that I fell to my death in a couple of years ago. The future is a sharp-dressed man alone in an empty conference room, contemplating his own mortality forever.