look at the paradox at the heart of the story namely the act of destruction is a form of creation

This theme is really addressing the cycle of life: the universal truth that things must die for others to be born. Trevor or "T" in the story wants to create art out of old Misery's rotting house. It was once beautiful but now lies in neglect; it is a relic of a structure that should have perished with the other structures during the blitz of WW2. If we can separate from the moral implications of destroying an old man's house, we can see T's existential vision. Misery's house needs to be saved from simply rotting to the ground. The house deserves a destruction as beautiful as its gravity defying staircase. T and the gang destroy it from the inside thus creating a work of art out of its ruin.