La Défense, a high-quality CBD, has seen an increasing vacancy rate year by year. Under this phenomenon caused by health problems and environmental issues, which allows for an exploration of the “Forest Invasion Plan,” the design is based on the understanding of urban forestry and the evolution of the forest ecosystem, using the forest as a carrier.Computation is used as a way to simulate and predict how the forest erodes buildings. This then in turn offers the possibility for design speculation in an opposite fashion to the greenwashing of architecture.