Glass 3D printing is subject to several fabrication limitations, with the major ones being a restriction to the achievable overhang, the need of a continuous printing path, and a path offset to reflect the nozzle size. It is therefore crucial to implement these limitations already during design stage to be able to generate feasible 3D-printed glass designs for the built environment. Although algorithms that consider such fabrication limitations exist in other 3D printed materials, there is not yet a Topology Optimization (TO) algorithm formulated specifically for glass 3D-printing as a fabrication process. Relevant TO algorithms for glass have been already developed by TU Delft for the design of massive cast glass structures; however, these integrate fabrication limitations linked to casting, which are neither fully encountered, nor fully applicable to glass printing. By building into our existing knowledge on the formulation of TO algorithms for cast glass structures and in collaboration with MIT and Evenline, we introduce the first TO algorithm specifically developed for 3D printed glass, integrating relevant fabrication limitations, such as an overhang restriction, the necessity for a continuous printing path and for path offsetting, while considering the substantial difference between the tensile and compressive strength of glass. The feasibility of the algorithm is validated through the first-ever 3D-printed, topology optimized glass component in the form of a stepping stone. Future research will focus on the further development of the Topology Optimization algorithm and on developing assembly systems for 3D printed glass structures made of numerous components.