Complex sentence: Nebbercracker had finished the house, knowing it was what she would have wanted but, aware that Constance's spirit made the house come alive, he pretended to hate children so as to keep them away.
Split into simpler sentences: Nebbercracker had finished the house, knowing it was what she would have wanted but. Aware that Constance's spirit made the house come alive, he pretended to hate children so as to keep them away.