Calculating the carbon footprint of buildings is a critical criterion for assessing their sustainability to reduce greenhouse gas emissions, which is anticipated by the new EU’s Energy Performance of Buildings Directive through a mandatory life-cycle carbon assessment of new buildings after 2028. This study examined the upfront embodied carbon of publicly funded multi-apartment buildings in Slovenia, following the methodology outlined in the Guidelines for low-carbon buildings of Slovenian public housing funds (SHF guidelines). The SHF guidelines methodology also includes the parking infrastructure in the calculations, which can include detached or underground parking garages. For selected projects, the material-related carbon footprint hotspots were identified and compared via various normalisation bases (floor area excluding/including parking and per capita). Then, the data was further analysed using descriptive statistics and compared to the data gathered from other countries in the EU (EU-ECB database). The results showed that the largest share of the production-related embodied carbon footprint (A1—A3 per EN 15978) is contributed by the load-bearing structure elements, representing the most significant potential for optimisation. The carbon footprint of the considered buidlings exceeded the median of the EU sample, highlighting specific characteristics of the data sample and an optimisation gap. The data highlight that the normalisation base influences the perception of environmental superiority and that including parking in the floor area scope can lower the GWP results on average by 25%. This indicated that clear rules need to be defined to enable a functional equivalent comparison between building projects.