Six Storey House by Geraldine McCaughrean
Six Storey House stands in its little garden like a potted palm: tall and thin and brownly dusty. Once, a single family lived there. They kept servants in the loft, where other people keep luggage, and a cook in the cellar, where other people keep wine. Now each floor has a different address: Flats 1 to 6, Six Storey House...Dexi lives on the third floor with his mother, but he knows all his neighbours very well. Each chapter follows the owners of a different flat, bringing each character beautifully to life. Gradually all the neighbours lives are woven more closely together until Dexi's final intervention, in the form of chicken-pox, sees the neighbours changing their lives - and their flats...