Reducing the embodied carbon footprint caused by construction projects is being pushed by many countries. One potential solution is the large-scale use of low-carbon building materials like geopolymers (GPs). GPs result from the chemical activation of aluminosilicate materials using an alkaline liquid, resulting in an inorganic polymeric network; it can also allow repurposing of the waste or by-products of industries. The sustainability of this new type of material is assessed here using Life Cycle Assessment (LCA). This study quantifies the cradle-to-gate environmental impacts of a localized geopolymer process in the Philippines and contrasts the impacts of Ordinary Portland Cement (OPC). The Life Cycle Inventory (LCI) analysis was performed using OpenLCA software and Life Cycle Impact Assessment (LCIA) using IPCC 2013 methodology. LCA results show that GP concrete with an RHA-based activator has a similar Global Warming Potential (GWP) as GP made using a commercial activator. The main contributors to the impacts are the production of the alkali activators, which indicates that the electricity generation mix has a significant influence on the environmental sustainability of GP.