This paper presents a comparative analysis of thermal performance and heating demand for selected residential (single-family houses, SFHs and multi-family houses, MFHs) and non-residential sectors (Offices and Schools). The thermal performance and space heating demand of the Swiss building stock were analysed by a bottom-up element-based archetypal model. SFHs are characterised by the best envelope thermal performance (average envelope U-value = 0.62 W/(m ² K)), followed by MFH (0.73 W/(m ² K)), Schools (0.75 W/(m ² K)), and Offices (0.84 W/(m ² K). Results show significant differences regarding architectural features between building sectors: SFHs are characterised by the highest envelope factor (median value = 2.00), defined as the ratio between external surfaces and heated area, followed by Schools (1.50), MFH (1.30), and Offices (1.25). As a consequence of the above-mentioned differences, SFHs show higher specific final energy demand for space heating (on average 148 kWh/(m ² year)), followed by Schools (117 kWh/(m ² year)), Offices (100 kWh/(m ² year)), and MFH (93 kWh/(m ² year)). Moreover, a high potential for decarbonisation of heating systems in the Swiss building stock was identified: more than 70% of the ERA is heated by fossil fuel-based heating systems, with some differences amongst the studied sectors. This analysis serves as an important starting point to examine possible retrofit pathways and policies across sectors.