A building falling down is read symbolically as a structure in life giving way — a belief, a routine or an arrangement that can no longer hold its weight. It speaks of change, not of literal danger.
Does the traditional reading fit your dream, or did it mean something else to you?
My Cosmic Code has a private dream journal. Write a dream down and the app picks out the symbols in it, shows what dream books say about them and, over time, which words recur across your entries. The journal is stored on your device only.