Geopolymer-based materials are a promising alternative to cementitious materials for 3D printing in the construction industry due to their sustainability and performance advantages [1]. However, the printability and buildability of geopolymer-based structures depend on various factors such as material properties, printing parameters, and design features [2]. This study investigates the printability and buildability of geopolymer-based 3D printed structures for built-environment applications. The study consists of three main steps: (1) characterization of geopolymer material properties; (2) numerical modeling and simulation of three different structures using finite element analysis and their experimental verification; and (3) sensitivity analysis of different printing parameters using design of experiments approach. The printed structures were compared with the numerical results regarding shape accuracy and buildability. The sensitivity analysis was performed using a factorial design method to evaluate the effects of nozzle diameter, layer height, and printing speed on the buildability of 3D-printed structures. The results show that the numerical model can reliably predict the buildability of geopolymer-based structures with good agreement with experimental data. The sensitivity analysis reveals that nozzle diameter, layer height, and printing speed are the most influential parameters affecting the buildability of 3D-printed structures. The study provides valuable insights for optimizing the 3D printing process of geopolymer-based materials and reducing the cost and time involved in this novel technology.