Twelve-year-old Rosie McGrady and her family are being kicked out of their apartment by developers and facing homelessness when they discover that they’ve inherited an enormous treehouse built by Rosie’s long-estranged great-great-grandfather on his estate. Having nowhere else to go, the McGradys move into the treehouse for an idyllic summer. However, come September, when Rosie starts at a new school, life in the treehouse becomes more complicated. Rosie finds it difficult to fit in at school, and when she finally makes a new friend, she lies, saying she inhabits the estate’s manor house, where her mysterious great-great-aunt Lydia lives. One lie leads to another until Rosie finds herself out on a limb with nowhere to go.

Banning’s whimsical first novel is filled with imaginative possibilities. All the details of treehouse life are included, right down to how the family copes without indoor plumbing or a bathroom (they dig an outhouse in the woods and use the community centre for showers). Banning makes her readers aware of both how exciting and difficult this experience is for Rosie, her younger sister, and her parents.

Having Rosie tell her story through a series of notebooks, one for each chapter, gives the story an extremely intimate feeling – it’s diary-like, though not as limiting as a series of diary entries would be. But Banning begins and ends the novel with the voice of great-great-aunt Lydia, a strange choice that distances the reader from Rosie. Still, young readers will finish Out on a Limb wanting to experience more of Rosie, her family, and their treehouse adventures.