This chapter examines how the architectural projects of Philip Augustus forged a new urban space, which ultimately engendered major demographic and topographical shifts, resulting in the building boom that began toward the end of his reign. It discusses the architecture created during this era particularly that of some of the lesser-known buildings of ancien Paris, offers insight on the distinct visual culture that emerged in and around the city during the thirteenth century. A key element in the construction of the urban identity of Paris was its architecture. The chapter presents a brief case-study of the Ste-Chapelle, to explain how elite buildings added prestige to the city as a whole and shaped the way people experienced it. Scholarship on the subject has offered a more democratic perspective, suggesting that Parisian Rayonnant was not specifically royal but rather a broader, more metropolitan architectural mode.