Urban-scale energy simulations deal with significant challenges, mainly the lack of comprehensive building datasets and the selection of a suitable simulation tool capable of accurately reflecting the complex interactions between urban buildings. In fact, available datasets are often either incomplete or obtained from the combination of multiple sources, thus requiring the homogenization of different data that can lead to errors or inaccuracies. Additionally, although urban-scale energy simulation tools often share a set of common inputs, the approach adopted for the simulation can re-quire peculiar variables for each tool, thus potentially compromising the reliability of the results. This study, conducted within the PRIN project URBEM, focuses on the critical use of building archetypes for urban-scale energy simulations, highlighting the main challenges faced by modelers. Simulations are carried out with two different simulation tools: UMI, based on the EnergyPlus engine, and EUReCA, based on a thermal resistance-capacitance approach. The comparison of the results aims to provide advice concerning the strengths and limitations of each approach while highlighting possible drawbacks in the implementation of the building archetypes already defined within the URBEM project and offering valuable recommendations for future urban-scale energy simulation efforts. Furthermore, the findings can support more informed decision-making for urban planning and tailored energy efficiency strategies.