I have seen two approaches to modeling properties in relational databases:
Create arbitrary tables that assume all the necessary components of the property. For example, have tables for room, unit, floor, building.
Have a single table 'asset'. Use a linking table to create relations between assets.
In either case, the building is represented as a general tree structure. This seems painful to query.
I need to represent this tree in order to implement an RBAC system. Now I'm not so sure that a relational DB is the best solution.