The Glass Castle is an imagined solar-powered house made entirely of glass that Dad vows to build once he has enough money. It operates as an important symbol on two levels. On the first level, it represents Dad’s ideal life: sustainable, self-sufficient, and not reliant on any larger authority. For Jeannette, however, the symbolism runs deeper. The Glass Castle comes to stand in for all her hopes and dreams concerning her father. He may be an alcoholic, he may be woefully underemployed, and he may be destructive and cruel at turns, but as long as he still plans to build the Glass Castle, he has the potential to be the kind of loving provider she long expects him to become.

Over the course of the book, this illusion falls apart. One particularly dramatic erosion of Jeannette’s hope in her father comes when Dad tells her to throw their mounting garbage piles into the hole she dug for the Glass Castle’s foundation. Over time, the Glass Castle comes to symbolize failure for Jeannette, while for Dad it comes to represent his preference for dreaming up impossible projects in lieu of doing the hard work of lifting his family out of poverty.