The architectural historian Andrew Saint records that Shaw sketched out the whole design for the "future fairy palace" in a single afternoon, while Armstrong and his guests were out on a shooting party. After this rapid initial design, Shaw worked on building the house for over 20 years. The long building period, and Armstrong's piecemeal, and changeable, approach to the development of the house, and his desire to retain the original shooting lodge at its core, occasionally led to tensions between client and architect, and to a building that lacks an overall unity. Armstrong changed the purpose of several rooms as his interests developed, and the German architectural historian Hermann Muthesius, writing just after Armstrong's death in 1900, noted that "the house did not find the unqualified favour with Shaw's followers that his previous works had done, nor did it entirely satisfy (Shaw)". Nevertheless, Shaw's abilities, as an architect and as a manager of difficult clients, ensured that Cragside was composed "with memorable force".