Micro location is a problem that many people are working on, but no one has solved yet.
One reason is that any radio frequency device, including Ibeacons, are 360 degree transmitters. So if it’s 30 meters out from a driveway gate, it’s also 30 meters in from that gate, which often takes you inside the house.
And defining a " room" is also tricky, because unlike a motion detector, the iBeacon detects through walls.
There are different approaches you can take, but nothing perfect yet.
Here’s the approach I took: using two devices and a transitional mode.
And here’s a topic with discussion of many microlocation strategies.