Digging into the Costs of Urban Soil Restoration[Les coûts de la restauration des sols urbains]

Urbanisation leads to soil compaction, pollution and sealing, degrading soils' ecological functions and ecosystem services essential for urban resilience, such as flood mitigation and climate regulation. Ecological restoration of urban soils is thus critical for sustainable and climate-adapted cities. However, the economic dimensions of urban soil restoration, particularly its costs, remain unexplored. This study estimates that median urban soil restoration costs range from 50 to 320€/m2 for compacted, sealed, or built-up soils, escalating to over 800€/m2 for polluted soils. Urban soil restoration involves a sequence of up to ten steps, combining several techniques, with significant cost variation. Preliminary analysis is the least expensive, while building deconstruction and pollution remediation are the most costly. These new cost estimates will facilitate the prioritization of restoration areas and the development of economic incentives for ecological restoration in cities. These finding also highlight the need for healthy soil preservation, alongside restoration efforts.