This chapter explores the various stages of transformation of buildings and architectural styles, from ancient to modern, and discusses the commonalities that were carried forward and the new elements that were introduced at different points of time. It focuses on amalgamating the study of process alongside that of the product with the hope that this would result in a comprehensive understanding of Delhi's built environment. The early forms of Islamic ornamentation were semi-naturalistic until Sunni revival in the medieval period when geometric order was applied to all art forms, including vegetal ornamentation, calligraphy and monumental inscriptions. The chapter explains the importance of geometry in Islamic architecture. In many extreme cases, innovative building forms were created at the compromise of essential functions of the building, and the continuity of this trend was put to halt. The use of an arcuate system in general allowed for the creation of bigger spaces as compared to the trabeated systems of Hindu temples.