Having a VR system figure out how to map and allow a user to interact with an entire building seems like something that's a bit far off, but that seems to be exactly what HTC is currently testing, with Valve's SteamVR as a backend. In the Tweeted video below, sent out by HTC China President Alvin Wang Grayling, shows a multiple room setup for an HTC Vive headset, and a previous Tweet implies that this is available to users. Another Twitter user by the name of Alan Yates managed to get the feature up and running with four trackers at a time.
Testing performed by Yates indicated that the feature can only lock on to up to four sensors per session, and it will normally be the first four that it sees in each session. Grayling actually chimed in on that Twitter thread to say that HTC's testing seems to be going best with one sensor in each room, which means that many users will be able to map out most of their house in VR with this tool. For now, each base station linked to a sensor or set of sensors needs to be on its own channel, and overlapping can cause strange effects. HTC is apparently working on a method, however, that would allow the sensors' sessions to intersect on the same channel, leading to a more accurate overall scan.
This feature is a part of the new SteamVR 2.0 beta, which means that you have to sign up for beta testing updates in order to give it a try, for now. HTC partnered up with Valve to help make the VIVE happen and pad out its library, so it's no surprise to see SteamVR being the first suite to support new features. For the time being, there seems to be no equivalent feature in other VR ecosystems, like with the Oculus Rift. Mutliple rooms in VR has a wide range of possible applications, with things like escape rooms and multiplayer VR games jumping immediately to mind. Valve specializes in software, so with SteamVR being the first VR backend to support this new feature in the VIVE, it's quite likely that Valve will also be the first to put out apps and games that take advantage of it.