Considering the recurring floods in recent years and the cost of disaster management, a need to improve flood damage assessment tools has been identified in Quebec (Canada). The lack of precision in the tools that are currently used can limit the effective management of resources. The objective of this project is to develop a tool to assess potential damage to building envelope components caused by flood events, taking into account the varying heights of water ingress to a building and the duration of exposure of the components to water. The intent is to develop correlations between water levels, duration of water exposure, and the short- and long-term damage to the envelope. The methodology is based on hygrothermal modelling and on hydraulics modelling of historical data to obtain different scenarios for water level and residence time. Given the lack of material properties, water uptake tests were performed in laboratory on typical construction materials used in basement and results from these tests were compared to those obtained by simulation. Thereafter, simulations were conducted of the wetting and drying of typical building envelope systems for different interior and exterior environmental conditions. An assessment was performed on both short- and long-term damage that could arise from various meteorological conditions and subsequent wetting scenarios. The evaluation utilized damage indicators such as swelling (short-term), as well as mold growth and wood biodegradation (rot) for long-term damage. In addition to the potential for improving damage assessment tools, the outcomes from this project will allow for the identification of envelope systems that are more resilient to flooding and the development of drying and retrofit guidelines towards the optimization of management flood mitigation protocols for building assets.