A simplified numerical model for rainwater runoff on building facades: Possibilities and limitations

► Development, evaluation and application of simplified rainwater runoff model. ► Transient model based on continuity equation and extension of Nusselt solution. ► Detailed discussion of model possibilities and model limitations. ► Model can easily be implemented in 2D Heat-Air-Moisture transfer models. ► Model evaluation with laboratory experiments and on-site runoff measurements.