WhiteMask Hi
If I understand correctly you have an object of type FloorMapV2 and you want to create the building from it?
If that's your question, here is more details:
Inside the FloorMapReader class there is a function you can use called:
DeserializeToScene(FloorMapV2 project)
If you want a demo script you can check out "DemoFloorMapPlayMode.cs" this scripts show how to load a json file, and deserialize it in the scene.
You can see it in action if you run the scene "FloorMap_PlayMode"
And there is more information in the manual as well.
hope that helps!