Seaweed is a promising potential building material, but so far in 2022, very little market ready seaweed-based building products are available. Because of the success of the sargassum adobe block in Mexico by Omar Vazquez, the potential of a seaweed loam bricks in the Netherlands is researched in this paper, called the seaweed brick. The realization of this seaweed bricks hinges on the seaweed having multiple purposes (water filtering, educational and bricks) and the use of waste streams from the proposed seaweed farms and other manufacturing processes. The production and beneficial functions of growing seaweed in harbor areas are shown in the design of Wierdok. Wierdok is the transformation of the former Petroleumhaven in Amsterdam to a Seaweed farm, Seaweed loam brick factory and exploration site for everyday people. By acknowledging the transforming neighborhood of harbor City and Westpoort, Wierdok transform in the same tempo as it’s surrounding creating the overlap between Industry and Recreation in an appropriate speed. In the meantime it exposed normal citizens to the option of sustainable building materials by highlighting the production process of the seaweed loam brick and the architecture it can create without diminishing the existing industrial harbor elements.