Describe symbolism in Buddenbrooks by Thomas Mann

In Part IX, the house on Mengstrasse is a symbol of the Buddenbrook family. In the same way that the Buddenbrooks bought their house on Mengstrasse as an up and coming family from a family in decline, so too do the up and coming Hagenstroms by the Buddenbrook house. It is clearly a symbol of the families decline and their lack of unity.