Perrelet and colleagues invert the dominant utilitarian logic of ecological engineering. Blue-green infrastructure is conventionally designed for stormwater, water quality or heat mitigation, with biodiversity treated as a secondary co-benefit. The paper argues for a bidirectional model: infrastructure should be engineered both with biodiversity—using ecological processes to improve performance—and for biodiversity—providing habitat and supporting species needs. This reciprocal formulation is its central theoretical innovation. It reveals trade-offs that disappear under one-way ecosystem-service thinking: leaf litter can support species while obstructing drainage; pollutants can be captured while accumulating through food chains. The methodological operation is interdisciplinary synthesis across engineering and ecology, oriented toward design guidance rather than abstract coexistence. Its wider bridge is to multispecies urbanism. Infrastructure becomes a negotiated habitat whose success cannot be defined exclusively by human service delivery; technical performance and ecological flourishing must be designed as interacting objectives.
URBANISM MEETS ART