Pluvial floods occur in small urban catchments when intense rainfall exceeds the stormwater drainage capacity. These events have been happening more frequently and with increasing impacts due to ongoing urbanization and the intensification of sub-daily precipitation extremes. Modeling these fast-evolving phenomena at very high spatial resolutions (1-5 m) is crucial to understand their dynamics and mitigate the impacts. In this work, we focus on better quantifying the role of building rooftops in the rainfall-runoff transformation involved in pluvial flooding. We adopt a modeling framework based on the LISFLOOD-FP rain-on-grid hydrodynamic model forced with gridded inputs of net precipitation, which accounts for the roof effects.