How does Henrik Ibsen use imagery in The Master Builder?

In Act II, Part II, the building of family homes..... literally on the ashes of the old house is a symbol of the hope possible even after the deepest tragedy. It's an ironic symbol because while building hope and happiness for other people Solness has been unable to build his own, or help Aline to build hers. The way he uses the image "a smoldering heap of ruins" to describe Aline's talent for raising children reinforces both the symbol and its irony.