Several experts focus on the environmental assessment of building materials using LCA methods, which aim to obtain scientifically relevant evidence for the environmentally optimal selection of preferred materials and products by identifying the sources of the most significant environmental impacts. Over the last 5 years, the number of scientific publications and studies dealing with the topic of LCA in the construction industry has doubled. Various methods can be used to calculate and estimate the environmental impacts of buildings and building materials during their life cycle. The paper compares the different LCA methods by analysing the global warming potentials (GWPs) of the selected building. The comparison of the GWPs calculated using the different assessment methods was carried out by identifying the constructions with the lowest and highest GWPs. The compared methods (CML, Environmental Footprint, ReCiPe, Impact World, BEES, TRACI and IPCC) differed from each other in the number and type of environmental impact categories in which the calculated results can be expressed as well as the environmental impact indicators. Although the absolute values of the calculated GWPs for the individual methods differed slightly, all assessment methods produced identical results in identifying structures with minimum and maximum impacts on climate change.