Across the world, urbanisation is placing marine and coastal habitats under increasing pressure. Seawalls are essential for shoreline protection, recreational activities and renewable energy generation but often lack the structural complexity required to support rich biodiversity. The Living Seawalls project, founded in Sydney, Australia, builds on marine research to design and produce modular ‘habitat tiles’ that mimic the living surface of marine plants and animals. The tiles can be attached to shoreline infrastructure to facilitate the colonisation of intertidal species such as oysters, barnacles, seaweeds and mussels. These species start the growth of an ecosystem by providing food and habitat for marine species and maintaining water quality. Over a thousand panels have been installed globally providing tangible benefits to local marine ecosystems.