The offshore wind (OW) energy plays a crucial role in the transition to a clean energy future aligned with the European Union’s Green Deal and Net Zero 2050 strategy and Norway’s commitment and contribution to achieving the climate goals. According to the International Energy Agency (IEA), the building- and construction sector represented 39% of energy and process-related CO2 emissions in 2018—of which 11% was related to steel and concrete. This work aims to assess the environmental impact of floating offshore wind turbine (FOWT) structures, comparing steel and concrete hulls through life cycle assessment (LCA). While OW offers a low-carbon alternative to fossil fuels, the manufacturing and transportation of FOWT structures contribute to greenhouse gas (GHG) emissions. We address the knowledge gap in LCA studies for FOWT structures by comparing two scenario objectives, (1) Steel hull, produced in China and shipped to Norway and and (2) Concrete hull, produced and installed near the Norwegian deployment site. We performed a literature review, and LCA study, to find CO2-equivalent emissions per ton, by breaking down the calculations in 30 FOWT units in steel versus concrete, by using material data to perform an assessment resulting in the Global Warming Potential (GWP) stated in tons of CO2e/T. The study reveals the importance of material selection and local production in reducing the environmental impact of FOWT structures, and concrete hulls exhibit significantly lower carbon footprint compared to steel hulls, with calculated emissions of 0.404 tons CO2-equivalent (CO2e) per ton of concrete and 2.76 tons CO2e per ton of steel. The study encourages further research in this area, highlighting the need for transparent data on the embodied carbon of materials and the potential benefits of incorporating recycled materials. By choosing FOWT structures with lower carbon footprints, decision-makers in the OW industry can contribute significantly to achieving the UN SDGs.