Materials and techniques of building have a profound influence on architecture, and hence architectural expression. Decorative precast concrete jalis distinguishes the Ahmedabad Panjarapol from any other cattle shed. Photographs of the Canteen for Mill Workers, now demolished, display a celebration of precast technology while some others like the NID, Shreyas School and the Sardar Patel Stadium show an expedient use of precast and cast-in-situ techniques. Precast construction required restructuring of the conventional concrete construction process – the sequential erection of formwork, placing reinforcement, pouring and curing of concrete – to alternating between design phase, production and assembly. Thus the study of precast elements (and the lack of it) across some reinforced concrete buildings in Ahmedabad between 1930 and 1980 throws light on some shifts in the processes of building and some factors that affected it. This paper aims to understand some of the factors that determined whether concrete was to be pre-cast or cast-in-situ and the effect it had in the conceptualisation of making, through some of the buildings that have been built in RCC, between 1930 and 1980 in Ahmedabad. Using the essay option four, I have explored the shift in the use of precast technology in the architecture of Ahmedabad.