In the era of sustainable development, glass-fiber reinforced polymer (GFRP) composites have made their way into modern engineering, construction, and building sectors due to their exponential characteristics. While considering the rapid growth and development in this sector, this research has assessed the relative environmental and techno-economic sustainability of two sorts of GFRP composite technologies: (a) filament winding and (b) pultrusion to effectively appraise their application, merits, and demerits. This study will help low-middle-income countries like Pakistan toward cleaner production, environmental management, and sustainable industrial development. The techno-economic sustainability is determined by using life cycle costing and techno-economic indicators, i.e., benefit-cost (B/C) ratio, net present value (NVP), internal rate of return (IRR), and payback period. The B/C ratio depicts the relationship between the relative cost and benefits of a technology, and NVP expresses the calculated present value of the future payback stream of a technological investment, while the IRR is an effective techno-economic indicators which can predict the efficacy of an investment, and the payback period is the time forecast for a technology to recover its investments. These techno-economic analytics showed that the net life-cycle cost performance, B/C ratio, and IRR are 5%, 7%, and 15% higher respectively for filament winding-based GFRP technology than the pultrusion-based manufacturing technology, whereas overall net life cycle benefits are about 80% greater for filament winding. Similarly, the payback time is shorter for filament winding compared to pultrusion. The environmental sustainability is determined, by employing a relative life cycle analysis (LCA) for both technologies. The system boundary for the study is "gate to gate," i.e., manufacturing phase, where these technologies are assessed for their environmental externalities. The functional unit of "1 kg finished product," i.e., manufactured by pultrusion and filament winding technology, and eight life cycle impact assessment (LCIA) categories; climate change potential (CCP), terrestrial eco-toxicity potential (TETP), ozone depletion potential (ODP), fossil resource depletion potential (FDP), acidification potential (AP), eutrophication potential (EP), particulate matter (PM) formation, and water consumption potential (WCP) have been selected. The significant ecological impact scores are determined in the categories of CCP (kg CO2 eq.) as 10.8E + 00 and 5.01E + 00 and ETP (kg. 2,4-D eq.) as 1.26E-02 and 9.47E-03 and FDP (kg Oil eq.) as 3.96E + 00 and 2.59E + 00 for filament winding and pultrusion-based GFRP technologies, respectively. These LCIA results depicted that the ecological performance of filament winding technology is specifically better than pultrusion technology in the categories of EP, PM, and WCP, while, for all other life cycle impact categories, the pultrusion technology has depicted significantly lower impact potential and is environmentally more sustainable. The outcomes of this research will be greatly assistive for researchers, developers, manufacturers, and policymakers to effectively appraise the externalities and selection of a more sustainable GFRP technology.