Inond’Act was created and developed by Master students from the Urban School of Sciences Po, in partnership with the Observatoire de l’Immobilier Durable (OID), from October 2024 to June 2025. The aim of this project was to develop a tool able to run a cost-benefit analysis, specific to flooding costs.

The model uses a component by component methodology to estimate flooding costs on a building. In short, the building is segmented into its different parts, and the model estimates the extent to which each part is damaged by a flood (for example, the damage to walls, floors, etc.). The final cost is then determined by summing up all these damages.

Adaptation measures reduce the flood’s damage, thereby affecting the final cost. Inond’Act automatically calculates which adaptation measures are the most cost effective for the building selected by the user.

You need two enter two types of information to run this model:

• Information regarding the flood you wish to simulate, like a river overflow or runoff flood (find out more here).

• Information regarding your building characteristics: whether it’s a building or apartment; its year of construction; etc.

The results of this model are based on pricing data which is naturally subject to change as each house and flood presents unique properties.

Inond’Act is an experimental model, and should solely be used for informational purposes.