As early eighteenth-century readers perused the first volume of Paul Decker’s Fürstliche Baumeister, oder Architectura civilis, they encountered an unexpected invitation: they were encouraged to imagine moving through a hypothetical princely palace. From the title of ‘Fürstliche Baumeister’, or ‘Princely Master Builder’, they knew that Decker would be offering them advice on good design – advice useful for a ‘master builder’ – and so would have expected the usual outline of design principles followed by various sample designs. These sequences of sample designs assumed a motionless reader who surveyed an overall structure, for each design was placed on a single page or half-page. On a page from the Italian Sebastiano Serlio’s Tutte l’opere d’architettura, et prospettiva of 1584, for instance, it is easy to evaluate the overall designs of two palaces since their facades and plans are aligned; one can compare how windows are placed across the exterior and illuminate the interior (Figure 1). Only authors of guidebooks led readers on tours of buildings to point out notable features and objects, and these buildings were built structures, in contrast to Decker’s hypothetical palace.

From the very first pages of his book, however, Decker suggests that his invitation to motion through a hypothetical palace is an effective, alternative approach to learning about good design. In his letter to the reader, he explains that his volume is the first of five examining building types from churches to hospitals and so implies a sweeping survey of ‘civil architecture’ that would be useful to a court architect.