There is a growing understanding of sustainability and economic issues of products in the circular economy sector but few studies on the incorporation of waste or maritime by-products of mollusc aquaculture in construction materials. SHELLTER project - Reuse of aquaculture waste in the development of construction materials - will contribute to the creation of opportunities for the exploitation of oyster shell waste from aquaculture or from invasive species as an industrial product for companies that are committed to the sustainability of construction materials. The Instituto Superior Técnico, University of Lisbon (Portugal) will closely work with Nofima (Norway) to improve oyster farming sustainability by recycling shell waste and creating new applications in building materials, boosting the circular economy. The activities carried out within the scope of the project are: Activity A1: Survey, field research and waste data collection; Activity A2: Technical feasibility of oyster shell particle size; Activity A3: Assessment of environmental and economic impacts; Activity A4: Development of a database and roadmap; Activity A5: Communication and dissemination.